TREM2 mutations are rare in a French cohort of patients with frontotemporal dementia.

PubMed

Lattante, Serena; Le Ber, Isabelle; Camuzat, Agnès; Dayan, Sarah; Godard, Chloé; Van Bortel, Inge; De Septenville, Anne; Ciura, Sorana; Brice, Alexis; Kabashi, Edor

2013-10-01

Homozygous mutations in TREM2 have been recently identified by exome sequencing in families presenting with frontotemporal dementia (FTD)-like phenotype. No study has evaluated the exact frequency of TREM2 mutations in cohorts of FTD patients so far. We sequenced TREM2 in 175 patients with pure FTD, mostly French, to test whether mutations could be implicated in the pathogenesis of the disease. No disease-causing mutation was identified in 175 individuals from the French cohort of FTD patients. We did not identify the polymorphism p.R47H (rs75932628), strongly associated with an increased risk of developing Alzheimer's disease. We conclude that TREM2 mutations are extremely rare in patients with pure FTD, although further investigation in larger populations is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

Defining the association of TMEM106B variants among frontotemporal lobar degeneration patients with GRN mutations and C9orf72 repeat expansions.

PubMed

Lattante, Serena; Le Ber, Isabelle; Galimberti, Daniela; Serpente, Maria; Rivaud-Péchoux, Sophie; Camuzat, Agnès; Clot, Fabienne; Fenoglio, Chiara; Scarpini, Elio; Brice, Alexis; Kabashi, Edor

2014-11-01

TMEM106B was identified as a risk factor for frontotemporal lobar degeneration (FTD) with TAR DNA-binding protein 43 kDa inclusions. It has been reported that variants in this gene are genetic modifiers of the disease and that this association is stronger in patients carrying a GRN mutation or a pathogenic expansion in chromosome 9 open reading frame 72 (C9orf72) gene. Here, we investigated the contribution of TMEM106B polymorphisms in cohorts of FTD and FTD with amyotrophic lateral sclerosis patients from France and Italy. Patients carrying the C9orf72 expansion (n = 145) and patients with GRN mutations (n = 76) were compared with a group of FTD patients (n = 384) negative for mutations and to a group of healthy controls (n = 552). In our cohorts, the presence of the C9orf72 expansion did not correlate with TMEM106B genotypes but the association was very strong in individuals with pathogenic GRN mutations (p = 9.54 × 10(-6)). Our data suggest that TMEM106B genotypes differ in FTD patient cohorts and strengthen the protective role of TMEM106B in GRN carriers. Further studies are needed to determine whether TMEM106B polymorphisms are associated with other genetic causes for FTD, including C9orf72 repeat expansions. Copyright © 2014 Elsevier Inc. All rights reserved.

The First Historically Reported Italian Family with FTD/ALS Teaches a Lesson on C9orf72 RE: Clinical Heterogeneity and Oligogenic Inheritance.

PubMed

Giannoccaro, Maria Pia; Bartoletti-Stella, Anna; Piras, Silvia; Casalena, Alfonsina; Oppi, Federico; Ambrosetto, Giovanni; Montagna, Pasquale; Liguori, Rocco; Parchi, Piero; Capellari, Sabina

2018-01-01

In 1969, Dazzi and Finizio reported the second observation of frontotemporal dementia (FTD) - amyotrophic lateral sclerosis (ALS) association in a large Italian kindred affected by an autosomal dominant form of ALS with high penetrance, frequent bulbar onset, and frequent cognitive decline. To expand the original characterization of this family and report the link with the C9orf72 repeat expansion (RE). We followed or reviewed the medical records of thirteen patients belonging to the original family and performed genetic analyses in four individuals. Eight patients presented with ALS, four with FTD, and one with schizophrenia. The C9orf72 RE was found in three patients but not in the healthy survivor. Additionally, we found a novel possible pathogenic variant in the ITM2B gene in one patient with a complex phenotype, associating movement disorders, psychiatric and cognitive features, deafness, and optic atrophy. The neuropathological examination of this patient did not show the classical features of ITM2B mutation related dementias suggesting that the putative pathogenic mechanism does not involve cellular mislocalization of the protein or the formation of amyloid plaques. We showed that the original Italian pedigree described with FTD/ALS carries the C9orf72 RE. Moreover, the finding of an additional mutation in another dementia causing gene in a patient with a more complex phenotype suggests a possible role of genetic modifiers in the disease. Together with other reports showing the coexistence of mutations in multiple ALS/FTD causative genes in the same family, our study supports an oligogenic etiology of ALS/FTD.

Familial Alzheimer disease-linked mutations specifically disrupt Ca2+ leak function of presenilin 1.

PubMed

Nelson, Omar; Tu, Huiping; Lei, Tianhua; Bentahir, Mostafa; de Strooper, Bart; Bezprozvanny, Ilya

2007-05-01

Mutations in presenilins are responsible for approximately 40% of all early-onset familial Alzheimer disease (FAD) cases in which a genetic cause has been identified. In addition, a number of mutations in presenilin-1 (PS1) have been suggested to be associated with the occurrence of frontal temporal dementia (FTD). Presenilins are highly conserved transmembrane proteins that support cleavage of the amyloid precursor protein by gamma-secretase. Recently, we discovered that presenilins also function as passive ER Ca(2+) leak channels. Here we used planar lipid bilayer reconstitution assays and Ca(2+) imaging experiments with presenilin-null mouse embryonic fibroblasts to analyze ER Ca(2+) leak function of 6 FAD-linked PS1 mutants and 3 known FTD-associated PS1 mutants. We discovered that L166P, A246E, E273A, G384A, and P436Q FAD mutations in PS1 abolished ER Ca(2+) leak function of PS1. In contrast, A79V FAD mutation or FTD-associated mutations (L113P, G183V, and Rins352) did not appear to affect ER Ca(2+) leak function of PS1 in our experiments. We validated our findings in Ca(2+) imaging experiments with primary fibroblasts obtained from an FAD patient possessing mutant PS1-A246E. Our results indicate that many FAD mutations in presenilins are loss-of-function mutations affecting ER Ca(2+) leak activity. In contrast, none of the FTD-associated mutations affected ER Ca(2+) leak function of PS1, indicating that the observed effects are disease specific. Our observations are consistent with the potential role of disturbed Ca(2+) homeostasis in Alzheimer disease pathogenesis.

A Novel Mechanism of Regulating the ATPase VPS4 by Its Cofactor LIP5 and the Endosomal Sorting Complex Required for Transport (ESCRT)-III Protein CHMP5

DOE PAGES

Vild, Cody J.; Li, Yan; Guo, Emily Z.; ...

2015-01-30

Disassembly of the endosomal sorting complex required for transport (ESCRT) machinery from biological membranes is a critical final step in cellular processes that require the ESCRT function. This reaction is catalyzed by VPS4, an AAA-ATPase whose activity is tightly regulated by a host of proteins, including LIP5 and the ESCRT-III proteins. In this paper, we present structural and functional analyses of molecular interactions between human VPS4, LIP5, and the ESCRT-III proteins. The N-terminal domain of LIP5 (LIP5NTD) is required for LIP5-mediated stimulation of VPS4, and the ESCRT-III protein CHMP5 strongly inhibits the stimulation. Both of these observations are distinct frommore » what was previously described for homologous yeast proteins. The crystal structure of LIP5NTD in complex with the MIT (microtubule-interacting and transport)-interacting motifs of CHMP5 and a second ESCRT-III protein, CHMP1B, was determined at 1 Å resolution. It reveals an ESCRT-III binding induced moderate conformational change in LIP5NTD, which results from insertion of a conserved CHMP5 tyrosine residue (Tyr 182) at the core of LIP5NTD structure. Finally, mutation of Tyr 182 partially relieves the inhibition displayed by CHMP5. Together, these results suggest a novel mechanism of VPS4 regulation in metazoans, where CHMP5 functions as a negative allosteric switch to control LIP5-mediated stimulation of VPS4.« less

hnRNPA2B1 and hnRNPA1 mutations are rare in patients with "multisystem proteinopathy" and frontotemporal lobar degeneration phenotypes.

PubMed

Le Ber, Isabelle; Van Bortel, Inge; Nicolas, Gael; Bouya-Ahmed, Kawtar; Camuzat, Agnès; Wallon, David; De Septenville, Anne; Latouche, Morwena; Lattante, Serena; Kabashi, Edor; Jornea, Ludmila; Hannequin, Didier; Brice, Alexis

2014-04-01

hnRNPA2B1 and hnRNPA1 mutations have been recently identified by exome sequencing in three families presenting with multisystem proteinopathy (MSP), a rare complex phenotype associating frontotemporal lobar degeneration (FTLD), Paget disease of bone (PDB), inclusion body myopathy (IBM), and amyotrophic lateral sclerosis (ALS). No study has evaluated the exact frequency of these genes in cohorts of MSP or FTD patients so far. We sequenced both genes in 17 patients with MSP phenotypes, and in 60 patients with FTLD and FTLD-ALS to test whether mutations could be implicated in the pathogenesis of these disorders. No disease-causing mutation was identified. We conclude that hnRNPA2B1 and hnRNPA1 mutations are rare in MSP and FTLD spectrum of diseases, although further investigations in larger populations are needed. Copyright © 2014 Elsevier Inc. All rights reserved.

Anti-CHMP5 single chain variable fragment antibody retrovirus infection induces programmed cell death of AML leukemic cells in vitro.

PubMed

Wang, Hai-rong; Xiao, Zhen-yu; Chen, Miao; Wang, Fei-long; Liu, Jia; Zhong, Hua; Zhong, Ji-hua; Ou-Yang, Ren-rong; Shen, Yan-lin; Pan, Shu-ming

2012-06-01

Over-expressed CHMP5 was found to act as oncogene that probably participated in leukemogenesis. In this study, we constructed the CHMP5 single chain variable fragment antibody (CHMP5-scFv) retrovirus and studied the changes of programmed cell death (PCD) of AML leukemic cells after infection by the retrovirus. The anti-CHMP5 KC14 hybridoma cell line was constructed to generate monoclonal antibody of CHMP5. The protein expression of CHMP5 was studied using immunofluorescence analysis. pMIG-CHMP5 scFv antibody expressible retroviral vector was constructed to prepare CHMP5-scFv retrovirus. AML leukemic U937 cells were infected with the retrovirus, and programmed cell death was studied using confocal microscope, FCM and Western blot. We obtained a monoclonal antibody of CHMP5, and found the expression of CHMP5 was up-regulated in the leukemic cells. After U937 cells were infected with CHMP5-scFv retrovirus, CHMP5 protein was neutralized. Moreover, the infection resulted in a significant increase in apoptosis and necrosis of U937 cells. In U937 cells infected with CHMP5-scFv retrovirus, apoptosis-inducing factor (AIF)-mediated caspase-independent necrotic PCD was activated, but autophagic programmed cell death was not observed. Neither the intrinsic nor extrinsic apoptotic PCD pathway was activated. The granzyme B/perforin-mediated caspase-dependent apoptotic PCD pathway was not activated. CHMP5-scFv retrovirus can neutralize the abnormally high levels of the CHMP5 protein in the cytosol of AML leukemic U937 cells, thereby inducing the programmed cell death of the leukemic cells via AIF-mediated caspase-independent necrosis and apoptosis.

ALS/FTD Mutation-Induced Phase Transition of FUS Liquid Droplets and Reversible Hydrogels into Irreversible Hydrogels Impairs RNP Granule Function

PubMed Central

Murakami, Tetsuro; Qamar, Seema; Lin, Julie Qiaojin; Schierle, Gabriele S. Kaminski; Rees, Eric; Miyashita, Akinori; Costa, Ana R.; Dodd, Roger B.; Chan, Fiona T.S.; Michel, Claire H.; Kronenberg-Versteeg, Deborah; Li, Yi; Yang, Seung-Pil; Wakutani, Yosuke; Meadows, William; Ferry, Rodylyn Rose; Dong, Liang; Tartaglia, Gian Gaetano; Favrin, Giorgio; Lin, Wen-Lang; Dickson, Dennis W.; Zhen, Mei; Ron, David; Schmitt-Ulms, Gerold; Fraser, Paul E.; Shneider, Neil A.; Holt, Christine; Vendruscolo, Michele; Kaminski, Clemens F.; St George-Hyslop, Peter

2015-01-01

Summary The mechanisms by which mutations in FUS and other RNA binding proteins cause ALS and FTD remain controversial. We propose a model in which low-complexity (LC) domains of FUS drive its physiologically reversible assembly into membrane-free, liquid droplet and hydrogel-like structures. ALS/FTD mutations in LC or non-LC domains induce further phase transition into poorly soluble fibrillar hydrogels distinct from conventional amyloids. These assemblies are necessary and sufficient for neurotoxicity in a C. elegans model of FUS-dependent neurodegeneration. They trap other ribonucleoprotein (RNP) granule components and disrupt RNP granule function. One consequence is impairment of new protein synthesis by cytoplasmic RNP granules in axon terminals, where RNP granules regulate local RNA metabolism and translation. Nuclear FUS granules may be similarly affected. Inhibiting formation of these fibrillar hydrogel assemblies mitigates neurotoxicity and suggests a potential therapeutic strategy that may also be applicable to ALS/FTD associated with mutations in other RNA binding proteins. PMID:26526393

SQSTM1 mutations in French patients with frontotemporal dementia or frontotemporal dementia with amyotrophic lateral sclerosis.

PubMed

Le Ber, Isabelle; Camuzat, Agnès; Guerreiro, Rita; Bouya-Ahmed, Kawtar; Bras, Jose; Nicolas, Gael; Gabelle, Audrey; Didic, Mira; De Septenville, Anne; Millecamps, Stéphanie; Lenglet, Timothée; Latouche, Morwena; Kabashi, Edor; Campion, Dominique; Hannequin, Didier; Hardy, John; Brice, Alexis

2013-11-01

Mutations in the SQSTM1 gene, coding for p62, are a cause of Paget disease of bone and amyotrophic lateral sclerosis (ALS). Recently, SQSTM1 mutations were confirmed in ALS, and mutations were also identified in 3 patients with frontotemporal dementia (FTD), suggesting a role for SQSTM1 in FTD. To evaluate the exact contribution of SQSTM1 to FTD and FTD with ALS (FTD-ALS) in an independent cohort of patients. A SQSTM1 mutation was first identified in a multiplex family with FTD by use of whole-exome sequencing. To evaluate the frequency of SQSTM1 mutations, we sequenced this gene in a cohort of patients with FTD or FTD-ALS, with no mutations in known FTD and ALS genes. Primary care or referral center. An overall cohort of 188 French patients, including 132 probands with FTD and 56 probands with FTD-ALS. Frequency of SQSTM1 mutations in patients with FTD or FTD-ALS; description of associated phenotypes. We identified 4 heterozygous missense mutations in 4 unrelated families with FTD; only 1 family had clinical symptoms of Paget disease of bone, and only 1 family had clinical symptoms of FTD-ALS, possibly owing to the low penetrance of some of the clinical manifestations. Although the frequency of the mutations is low in our series (4 of 188 patients [2%]), our results, similar to those already reported, support a direct pathogenic role of p62 in different types of FTD.

Mutations in UBQLN2 and SIGMAR1 genes are rare in Korean patients with amyotrophic lateral sclerosis.

PubMed

Kim, Hee-Jung; Kwon, Min-Jung; Choi, Won-Jun; Oh, Ki-Wook; Oh, Seong-Il; Ki, Chang-Seok; Kim, Seung Hyun

2014-08-01

Mutations in the UBQLN2 and SIGMAR1 genes were recently identified in X-linked dominant amyotrophic lateral sclerosis and/or frontotemporal dementia (ALS and/or FTD) and FTD and/or motor neuron disease, respectively. Subsequent studies, however, found that UBQLN2 mutations were rare, and the pathogenicity of SIGMAR1 mutation in FTD and/or motor neuron disease was controversial. In the present study, we analyzed mutations in the UBQLN2 and SIGMAR1 genes in a Korean cohort of 258 patients with familial ALS (n = 9) or sporadic (sALS; n = 258) ALS. One novel UBQLN2 variant (p.D314E) was observed in 2 patients with sALS and 5 of 727 controls indicating that this variant might be a rare polymorphism rather than a disease-causing mutation. A novel SIGMAR1 gene variant in the 3'-untranslated region (c.*58T>C) was found in 1 sALS and was absent in 727 control samples. Taken together, our data suggest that causative mutations in the UBQLN2 and SIGMAR1 genes are rare in Korean patients with either familial or sporadic ALS. Copyright © 2014 Elsevier Inc. All rights reserved.

Synaptic dysfunction and altered excitability in C9ORF72 ALS/FTD.

PubMed

Starr, Alexander; Sattler, Rita

2018-08-15

Amyotrophic lateral sclerosis (ALS) is characterized by a progressive degeneration of upper and lower motor neurons, resulting in fatal paralysis due to denervation of the muscle. Due to genetic, pathological and symptomatic overlap, ALS is now considered a spectrum disease together with frontotemporal dementia (FTD), the second most common cause of dementia in individuals under the age of 65. Interestingly, in both diseases, there is a large prevalence of RNA binding proteins (RBPs) that are mutated and considered disease-causing, or whose dysfunction contribute to disease pathogenesis. The most common shared genetic mutation in ALS/FTD is a hexanucleuotide repeat expansion within intron 1 of C9ORF72 (C9). Three potentially overlapping, putative toxic mechanisms have been proposed: loss of function due to haploinsufficient expression of the C9ORF72 mRNA, gain of function of the repeat RNA aggregates, or RNA foci, and repeat-associated non-ATG-initiated translation (RAN) of the repeat RNA into toxic dipeptide repeats (DPRs). Regardless of the causative mechanism, disease symptoms are ultimately caused by a failure of neurotransmission in three regions: the brain, the spinal cord, and the neuromuscular junction. Here, we review C9 ALS/FTD-associated synaptic dysfunction and aberrant neuronal excitability in these three key regions, focusing on changes in morphology and synapse formation, excitability, and excitotoxicity in patients, animal models, and in vitro models. We compare these deficits to those seen in other forms of ALS and FTD in search of shared pathways, and discuss the potential targeting of synaptic dysfunctions for therapeutic intervention in ALS and FTD patients. Copyright © 2018 Elsevier B.V. All rights reserved.

Examining the language and behavioural profile in FTD and ALS-FTD.

PubMed

Saxon, Jennifer A; Thompson, Jennifer C; Jones, Matthew; Harris, Jennifer M; Richardson, Anna Mt; Langheinrich, Tobias; Neary, David; Mann, David Ma; Snowden, Julie S

2017-08-01

A proportion of patients with behavioural variant frontotemporal dementia (bvFTD) develop amyotrophic lateral sclerosis (ALS). It is currently unknown whether the behavioural and cognitive syndrome in bvFTD with ALS (ALS-FTD) is indistinguishable from that of bvFTD alone. A retrospective cohort of 241 patients with clinical diagnoses of bvFTD (n=185) or ALS-FTD (n=56) was examined with respect to behavioural, cognitive and neuropsychiatric symptoms. Features were rated as present or absent based on information recorded from clinical interviews and detailed neuropsychological assessment. A number of behavioural and affective changes were reported more frequently in bvFTD than ALS-FTD: social disinhibition (p<0.001), inertia (p<0.001), loss of sympathy and empathy (p = 0.008), repetitive behaviours (p<0.001) and dietary changes (p<0.001). Warmth of affect demonstrated in the clinic setting was reported more often in ALS-FTD than bvFTD (p<0.001). Executive impairments occurred equally in both groups. Language impairments were more common in ALS-FTD than bvFTD: agrammatism (p<0.017) and impaired sentence comprehension (p<0.036). Psychotic features were relatively rare and did not distinguish the groups. Our findings suggest differences between bvFTD and ALS-FTD. In particular, while changes in social behaviour are prominent in bvFTD alone, there may be a comparatively greater degree of language impairment in ALS-FTD. Prospective exploration of the pattern of differences between these groups will be essential. Identification of a distinct neuropsychological phenotype in ALS-FTD may have clinical implications for early diagnosis, disease management and care planning and theoretical implications for our understanding of the relationship between ALS and FTD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

SQSTM1 Mutations in French Patients With Frontotemporal Dementia or Frontotemporal Dementia With Amyotrophic Lateral Sclerosis

PubMed Central

Le Ber, Isabelle; Camuzat, Agnès; Guerreiro, Rita; Bouya-Ahmed, Kawtar; Bras, Jose; Nicolas, Gael; Gabelle, Audrey; Didic, Mira; De Septenville, Anne; Millecamps, Stéphanie; Lenglet, Timothée; Latouche, Morwena; Kabashi, Edor; Campion, Dominique; Hannequin, Didier; Hardy, John; Brice, Alexis

2014-01-01

IMPORTANCE Mutations in the SQSTM1 gene, coding for p62, are a cause of Paget disease of bone and amyotrophic lateral sclerosis (ALS). Recently, SQSTM1 mutations were confirmed in ALS, and mutations were also identified in 3 patients with frontotemporal dementia (FTD), suggesting a role for SQSTM1 in FTD. OBJECTIVE To evaluate the exact contribution of SQSTM1 to FTD and FTD with ALS (FTD-ALS) in an independent cohort of patients. DESIGN A SQSTM1 mutation was first identified in a multiplex family with FTD by use of whole-exome sequencing. To evaluate the frequency of SQSTM1 mutations, we sequenced this gene in a cohort of patients with FTD or FTD-ALS, with no mutations in known FTD and ALS genes. SETTING Primary care or referral center. PARTICIPANTS An overall cohort of 188 French patients, including 132 probands with FTD and 56 probands with FTD-ALS. MAIN OUTCOMES AND MEASURES Frequency of SQSTM1 mutations in patients with FTD or FTD-ALS; description of associated phenotypes. RESULTS We identified 4 heterozygous missense mutations in 4 unrelated families with FTD; only 1 family had clinical symptoms of Paget disease of bone, and only 1 family had clinical symptoms of FTD-ALS, possibly owing to the low penetrance of some of the clinical manifestations. CONCLUSIONS AND RELEVANCE Although the frequency of the mutations is low in our series (4 of 188 patients [2%]), our results, similar to those already reported, support a direct pathogenic role of p62 in different types of FTD. PMID:24042580

Mutation of Breast Cancer Cell Genomic DNA by APOBEC3B

DTIC Science & Technology

2012-09-01

down Yes, A3B expression increases the steady-state level of genomic uracil Fig. 2a-2c 2) Can A3B mutate a target gene to escape drug...somatic mutation in human cancer genomes. Nature 446, 153-158 (2007). 10 2 Jones, S. et al. Frequent mutations of chromatin remodeling gene ARID1A in...processes molding the genomes of 21 breast cancers. Cell 149, 979-993 (2012). 9 Stephens, P. J. et al. The landscape of cancer genes and mutational

Defining the genetic connection linking amyotrophic lateral sclerosis (ALS) with frontotemporal dementia (FTD).

PubMed

Lattante, Serena; Ciura, Sorana; Rouleau, Guy A; Kabashi, Edor

2015-05-01

Several genetic causes have been recently described for neurological diseases, increasing our knowledge of the common pathological mechanisms involved in these disorders. Mutation analysis has shown common causative factors for two major neurodegenerative disorders, ALS and FTD. Shared pathological and genetic markers as well as common neurological signs between these diseases have given rise to the notion of an ALS/FTD spectrum. This overlap among genetic factors causing ALS/FTD and the coincidence of mutated alleles (including causative, risk and modifier variants) have given rise to the notion of an oligogenic model of disease. In this review we summarize major advances in the elucidation of novel genetic factors in these diseases which have led to a better understanding of the common pathogenic factors leading to neurodegeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

TFAP2B mutation and dental anomalies.

PubMed

Tanasubsinn, Natchaya; Sittiwangkul, Rekwan; Pongprot, Yupada; Kawasaki, Katsushige; Ohazama, Atsushi; Sastraruji, Thanapat; Kaewgahya, Massupa; Kantaputra, Piranit Nik

2017-08-01

Mutations inTFAP2B has been reported in patients with isolated patent ductus arteriosus (PDA) and Char syndrome. We performed mutation analysis of TFAP2B in 43 patients with isolated PDA, 7 patients with PDA with other congenital heart defects and 286 patients with isolated tooth agenesis with or without other dental anomalies. The heterozygous c.1006G>A mutation was identified in 20 individuals. Those mutation carriers consisted of 1 patient with term PDA (1/43), 16 patients with isolated tooth agenesis with or without other dental anomalies (16/286; 5.6%), 1 patient with PDA and severe valvular aortic stenosis and tooth agenesis (1/4) and 2 normal controls (2/100; 1%). The mutation is predicted to cause an amino-acid substitution p.Val336Ile in the TFAP2B protein. Tfap2b expression during early mouse tooth development supports the association of TFAP2B mutation and dental anomalies. It is hypothesized that this incidence might have been the result of founder effect. Here we report for the first time that TFAP2B mutation is associated with tooth agenesis, microdontia, supernumerary tooth and root maldevelopment. In addition, we also found that TFAP2B mutations, the common causes of PDA in Caucasian, are not the common cause of PDA in Thai population.

The behavioural variant frontotemporal dementia (bvFTD) syndrome in psychiatry

PubMed Central

Lanata, Serggio C; Miller, Bruce L

2016-01-01

The primary goal of this article is to critically discuss the syndromic overlap that exists between early behavioural variant frontotemporal dementia (bvFTD)—the most common clinical syndrome associated with frontotemporal lobar degeneration (FTLD)—and several primary psychiatric disorders. We begin by summarising the current state of knowledge regarding FTLD, including the recent discovery of FTLD-causative genetic mutations. Clinicopathological correlations in FTLD are subsequently discussed, while emphasising that clinical syndromes of FTD are dictated by the distribution of FTLD pathology in the brain. We then review a large number of cases with suspected and confirmed bvFTD that had previously been diagnosed with a primary psychiatric disorder. The clinical and neuroscientific implications of this overlap are discussed, focusing on the importance of early diagnosis for clinical and therapeutic reasons. We propose that largely due to the paucity of biomarkers for primary psychiatric disorders, and the limited use of FTLD-related biomarkers by psychiatrists at present, it is very difficult to separate patients with early bvFTD from those with primary psychiatric disorders based on clinical grounds. Furthermore, specific limitations of the Diagnostic and Statistical Manual of Mental Disorders (DSM) 5 criteria for bvFTD may inadvertently discourage recognition of bvFTD in mental health settings. Clinically, more research is needed to develop tools that allow early differentiation of bvFTD from primary psychiatric disease, as bvFTD therapies will likely be most effective in the earliest stages of disease. From a neuroscience perspective, we argue that bvFTD provides an excellent paradigm for investigating the neural basis of psychiatric disorders. PMID:26216940

The Spectrum of Mutations in Progranulin

PubMed Central

Yu, Chang-En; Bird, Thomas D.; Bekris, Lynn M.; Montine, Thomas J.; Leverenz, James B.; Steinbart, Ellen; Galloway, Nichole M.; Feldman, Howard; Woltjer, Randall; Miller, Carol A.; Wood, Elisabeth McCarty; Grossman, Murray; McCluskey, Leo; Clark, Christopher M.; Neumann, Manuela; Danek, Adrian; Galasko, Douglas R.; Arnold, Steven E.; Chen-Plotkin, Alice; Karydas, Anna; Miller, Bruce L.; Trojanowski, John Q.; Lee, Virginia M.-Y.; Schellenberg, Gerard D.; Van Deerlin, Vivianna M.

2010-01-01

Background Mutation in the progranulin gene (GRN) can cause frontotemporal dementia (FTD). However, it is unclear whether some rare FTD-related GRN variants are pathogenic and whether neurodegenerative disorders other than FTD can also be caused by GRN mutations. Objectives To delineate the range of clinical presentations associated with GRN mutations and to define pathogenic candidacy of rare GRN variants. Design Case-control study. Setting Clinical and neuropathology dementia research studies at 8 academic centers. Participants Four hundred thirty-four patients with FTD, including primary progressive aphasia, semantic dementia, FTD/amyotrophic lateral sclerosis (ALS), FTD/motor neuron disease, corticobasal syndrome/corticobasal degeneration, progressive supranuclear palsy, Pick disease, dementia lacking distinctive histopathology, and pathologically confirmed cases of frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U); and 111 non-FTD cases (controls) in which TDP-43 deposits were a prominent neuropathological feature, including subjects with ALS, Guam ALS and/or parkinsonism dementia complex, Guam dementia, Alzheimer disease, multiple system atrophy, and argyrophilic grain disease. Main Outcome Measures Variants detected on sequencing of all 13 GRN exons and at least 80 base pairs of flanking introns, and their pathogenic candidacy determined by in silico and ex vivo splicing assays. Results We identified 58 genetic variants that included 26 previously unknown changes. Twenty-four variants appeared to be pathogenic, including 8 novel mutations. The frequency of GRN mutations was 6.9% (30 of 434) of all FTD-spectrum cases, 21.4% (9 of 42) of cases with a pathological diagnosis of FTLD-U, 16.0% (28 of 175) of FTD-spectrum cases with a family history of a similar neurodegenerative disease, and 56.2% (9 of 16) of cases of FTLD-U with a family history. Conclusions Pathogenic mutations were found only in FTD-spectrum cases and not in other

Pre-S2 Start Codon Mutation of Hepatitis B Virus Subgenotype B3 Effects on NF-κB Expression and Activation in Huh7 Cell Lines.

PubMed

Siburian, Marlinang Diarta; Suriapranata, Ivet Marita; Wanandi, Septelia Inawati

2018-03-19

A cross-sectional study on hepatitis B patients in Indonesia showed association of pre-S2 start codon mutation (M120 V) with cirrhosis and hepatocellular carcinoma (HCC), which was dissimilar from studies from other populations where pre-S2 deletion mutation was more prevalent. Different mutation patterns were attributed to different hepatitis B virus (HBV) subgenotypes in each population study. HBV surface proteins are reported to induce the activation of NF-κB, a transcriptional factor known to play an important role in the development of liver disease. This study aimed to see the effects of HBs variants in HBV subgenotype B3 on the expression and activation of NF-κB as one of the mechanisms in inducing advanced liver disease. HBV subgenotypes B3, each carrying wild-type (wt) HBs, M120 V, and pre-S2 deletion mutation were isolated from three HCC patients. HBs genes were amplified and cloned into pcDNA3.1 and were transfected using Lipofectamine into a Huh7 cell line. NF-κB activation was measured through IκB-α expression, which is regulated by NF-κB. RNA expressions for HBs, IκB-α, and NF-κB subunit (p50) were evaluated using real-time PCR. M120 V mutant had a significantly higher mRNA level compared with wt and pre-S2 deletion mutant; however, there were no significant differences in HBs protein expressions. The transcription level of p50 was higher in M120 V mutation compared with HBs wild-type and pre-S2 deletion mutant. NF-κB activation was higher in HBs wild-type compared with the two mutant variants. Pre-S2 mutations had no effect on the increment of NF-κB activation. However, M120 V mutation may utilize a different pathway in liver disease progression that involves high expression of NF-κB subunit, p50.

Reducing inflammation and rescuing FTD-related behavioral deficits in progranulin-deficient mice with α7 nicotinic acetylcholine receptor agonists.

PubMed

Minami, S Sakura; Shen, Vivian; Le, David; Krabbe, Grietje; Asgarov, Rustam; Perez-Celajes, Liberty; Lee, Chih-Hung; Li, Jinhe; Donnelly-Roberts, Diana; Gan, Li

2015-10-15

Mutations in the progranulin gene cause frontotemporal dementia (FTD), a debilitating neurodegenerative disease that involves atrophy of the frontal and temporal lobes and affects personality, behavior, and language. Progranulin-deficient mouse models of FTD exhibit deficits in compulsive and social behaviors reminiscent of patients with FTD, and develop excessive microgliosis and increased release of inflammatory cytokines. Activation of nicotinic acetylcholine receptors (nAChRs) by nicotine or specific α7 nAChR agonists reduces neuroinflammation. Here, we investigated whether activation of nAChRs by nicotine or α7 agonists improved the excessive inflammatory and behavioral phenotypes of a progranulin-deficient FTD mouse model. We found that treatment with selective α7 agonists, PHA-568487 or ABT-107, strongly suppressed the activation of NF-κB in progranulin-deficient cells. Treatment with ABT-107 also reduced microgliosis, decreased TNFα levels, and reduced compulsive behavior in progranulin-deficient mice. Collectively, these data suggest that targeting activation of the α7 nAChR pathway may be beneficial in decreasing neuroinflammation and reversing some of the behavioral deficits observed in progranulin-deficient FTD. Copyright © 2015. Published by Elsevier Inc.

Automatic measurement of prosody in behavioral variant FTD.

PubMed

Nevler, Naomi; Ash, Sharon; Jester, Charles; Irwin, David J; Liberman, Mark; Grossman, Murray

2017-08-15

To help understand speech changes in behavioral variant frontotemporal dementia (bvFTD), we developed and implemented automatic methods of speech analysis for quantification of prosody, and evaluated clinical and anatomical correlations. We analyzed semi-structured, digitized speech samples from 32 patients with bvFTD (21 male, mean age 63 ± 8.5, mean disease duration 4 ± 3.1 years) and 17 matched healthy controls (HC). We automatically extracted fundamental frequency (f0, the physical property of sound most closely correlating with perceived pitch) and computed pitch range on a logarithmic scale (semitone) that controls for individual and sex differences. We correlated f0 range with neuropsychiatric tests, and related f0 range to gray matter (GM) atrophy using 3T T1 MRI. We found significantly reduced f0 range in patients with bvFTD (mean 4.3 ± 1.8 ST) compared to HC (5.8 ± 2.1 ST; p = 0.03). Regression related reduced f0 range in bvFTD to GM atrophy in bilateral inferior and dorsomedial frontal as well as left anterior cingulate and anterior insular regions. Reduced f0 range reflects impaired prosody in bvFTD. This is associated with neuroanatomic networks implicated in language production and social disorders centered in the frontal lobe. These findings support the feasibility of automated speech analysis in frontotemporal dementia and other disorders. © 2017 American Academy of Neurology.

Characterization of the 3p12.3-pcen region associated with tumor suppression in a novel ovarian cancer cell line model genetically modified by chromosome 3 fragment transfer.

PubMed

Cody, Neal A L; Shen, Zhen; Ripeau, Jean-Sebastien; Provencher, Diane M; Mes-Masson, Anne-Marie; Chevrette, Mario; Tonin, Patricia N

2009-12-01

The genetic analysis of nontumorigenic radiation hybrids generated by transfer of chromosome 3 fragments into the tumorigenic OV-90 ovarian cancer cell line identified the 3p12.3-pcen region as a candidate tumor suppressor gene (TSG) locus. In the present study, polymorphic microsatellite repeat analysis of the hybrids further defined the 3p12.3-pcen interval to a 16.1 Mb common region containing 12 known or hypothetical genes: 3ptel-ROBO2-ROBO1-GBE1-CADM2-VGLL3-CHMP2B-POU1F1-HTR1F-CGGBP1-ZNF654-C3orf38-EPHA3-3pcen. Seven of these genes, ROBO1, GBE1, VGLL3, CHMP2B, CGGBP1, ZNF654, and C3orf38, exhibited gene expression in the hybrids, placing them as top TSG candidates for further analysis. The expression of all but one (VGLL3) of these genes was also detected in the parental OV-90 cell line. Mutations were not identified in a comparative sequence analysis of the predicted protein coding regions of these candidates in OV-90 and donor normal chromosome 3 contig. However, the nondeleterious sequence variants identified in the transcribed regions distinguished parent of origin alleles for ROBO1, VGLL3, CHMP2B, and CGGBP1 and cDNA sequencing of the hybrids revealed biallelic expression of these genes. Interestingly, underexpression of VGLL3 and ZNF654 were observed in malignant ovarian tumor samples as compared with primary cultures of normal ovarian surface epithelial cells or benign ovarian tumors, and this occurred regardless of allelic content of 3p12.3-pcen. The results taken together suggest that dysregulation of VGLL3 and/or ZNF654 expression may have affected pathways important in ovarian tumorigenesis which was offset by the transfer of chromosome 3 fragments in OV-90, a cell line hemizygous for 3p.

Quantitative EEG and LORETA: valuable tools in discerning FTD from AD?

PubMed

Caso, Francesca; Cursi, Marco; Magnani, Giuseppe; Fanelli, Giovanna; Falautano, Monica; Comi, Giancarlo; Leocani, Letizia; Minicucci, Fabio

2012-10-01

Drawing a clinical distinction between frontotemporal dementia (FTD) and Alzheimer's disease (AD) is tricky, particularly at the early stages of disease. This study evaluates the possibility in differentiating 39 FTD, 39 AD, and 39 controls (CTR) by means of power spectral analysis and standardized low resolution brain electromagnetic tomography (sLORETA) within delta, theta, alpha 1 and 2, beta 1, 2, and 3 frequency bands. Both analyses revealed in AD patients, relative to CTR, higher expression of diffuse delta/theta and lower central/posterior fast frequency (from alpha1 to beta2) bands. FTD patients showed diffuse increased theta power compared with CTR and lower delta relative to AD patients. Compared with FTD, AD patients showed diffuse higher theta power at spectral analysis and, at sLORETA, decreased alpha2 and beta1 values in central/temporal regions. Spectral analysis and sLORETA provided complementary information that might help characterizing different patterns of electroencephalogram (EEG) oscillatory activity in AD and FTD. Nevertheless, this differentiation was possible only at the group level because single patients could not be discerned with sufficient accuracy. Copyright © 2012 Elsevier Inc. All rights reserved.

A proteomic network approach across the ALS-FTD disease spectrum resolves clinical phenotypes and genetic vulnerability in human brain.

PubMed

Umoh, Mfon E; Dammer, Eric B; Dai, Jingting; Duong, Duc M; Lah, James J; Levey, Allan I; Gearing, Marla; Glass, Jonathan D; Seyfried, Nicholas T

2018-01-01

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative diseases with overlap in clinical presentation, neuropathology, and genetic underpinnings. The molecular basis for the overlap of these disorders is not well established. We performed a comparative unbiased mass spectrometry-based proteomic analysis of frontal cortical tissues from postmortem cases clinically defined as ALS, FTD, ALS and FTD (ALS/FTD), and controls. We also included a subset of patients with the C9orf72 expansion mutation, the most common genetic cause of both ALS and FTD Our systems-level analysis of the brain proteome integrated both differential expression and co-expression approaches to assess the relationship of these differences to clinical and pathological phenotypes. Weighted co-expression network analysis revealed 15 modules of co-expressed proteins, eight of which were significantly different across the ALS-FTD disease spectrum. These included modules associated with RNA binding proteins, synaptic transmission, and inflammation with cell-type specificity that showed correlation with TDP-43 pathology and cognitive dysfunction. Modules were also examined for their overlap with TDP-43 protein-protein interactions, revealing one module enriched with RNA-binding proteins and other causal ALS genes that increased in FTD/ALS and FTD cases. A module enriched with astrocyte and microglia proteins was significantly increased in ALS cases carrying the C9orf72 mutation compared to sporadic ALS cases, suggesting that the genetic expansion is associated with inflammation in the brain even without clinical evidence of dementia. Together, these findings highlight the utility of integrative systems-level proteomic approaches to resolve clinical phenotypes and genetic mechanisms underlying the ALS-FTD disease spectrum in human brain. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Clinical characterization of bvFTD due to FUS neuropathology

PubMed Central

Lee, Suzee E.; Seeley, William W.; Poorzand, Pardis; Rademakers, Rosa; Karydas, Anna; Stanley, Christine M.; Miller, Bruce L.; Rankin, Katherine P.

2011-01-01

In 2009, inclusions containing the fused in sarcoma (FUS) protein were identified as a third major molecular class of pathology underlying the behavioral variant frontotemporal dementia (bvFTD) syndrome. Due to the low prevalence of FUS pathology, few clinical descriptions have been published and none provides information about specific social-emotional deficits despite evidence for severe behavioral manifestations in this disorder. We evaluated a patient with bvFTD due to FUS pathology using a comprehensive battery of cognitive and social-emotional tests. A structural MRI scan and genetic tests for tau, progranulin, and FUS mutations were also performed. The patient showed preserved general cognitive functioning and superior working memory, but severe deficits in emotion attribution, sensitivity to punishment, and the capacity for interpersonal warmth and empathy. The gray matter atrophy pattern corresponded to this focal deficit profile, with preservation of dorsolateral fronto-parietal regions associated with executive functioning but severe damage to right worse than left frontoinsula, temporal pole, subgenual anterior cingulate, medial orbitofrontal cortex, amygdala, and caudate. This patient demonstrates the striking focality associated with FUS neuropathology in patients with bvFTD. PMID:22060063

Clinical spectrum of 4H leukodystrophy caused by POLR3A and POLR3B mutations

PubMed Central

Vanderver, Adeline; van Spaendonk, Rosalina M.L.; Schiffmann, Raphael; Brais, Bernard; Bugiani, Marianna; Sistermans, Erik; Catsman-Berrevoets, Coriene; Kros, Johan M.; Pinto, Pedro Soares; Pohl, Daniela; Tirupathi, Sandya; Strømme, Petter; de Grauw, Ton; Fribourg, Sébastien; Demos, Michelle; Pizzino, Amy; Naidu, Sakkubai; Guerrero, Kether; van der Knaap, Marjo S.; Bernard, Geneviève

2014-01-01

Objective: To study the clinical and radiologic spectrum and genotype–phenotype correlation of 4H (hypomyelination, hypodontia, hypogonadotropic hypogonadism) leukodystrophy caused by mutations in POLR3A or POLR3B. Methods: We performed a multinational cross-sectional observational study of the clinical, radiologic, and molecular characteristics of 105 mutation-proven cases. Results: The majority of patients presented before 6 years with gross motor delay or regression. Ten percent had an onset beyond 10 years. The disease course was milder in patients with POLR3B than in patients with POLR3A mutations. Other than the typical neurologic, dental, and endocrine features, myopia was seen in almost all and short stature in 50%. Dental and hormonal findings were not invariably present. Mutations in POLR3A and POLR3B were distributed throughout the genes. Except for French Canadian patients, patients from European backgrounds were more likely to have POLR3B mutations than other populations. Most patients carried the common c.1568T>A POLR3B mutation on one allele, homozygosity for which causes a mild phenotype. Systematic MRI review revealed that the combination of hypomyelination with relative T2 hypointensity of the ventrolateral thalamus, optic radiation, globus pallidus, and dentate nucleus, cerebellar atrophy, and thinning of the corpus callosum suggests the diagnosis. Conclusions: 4H is a well-recognizable clinical entity if all features are present. Mutations in POLR3A are associated with a more severe clinical course. MRI characteristics are helpful in addressing the diagnosis, especially if patients lack the cardinal non-neurologic features. PMID:25339210

A gain-of-function mutation in Tnni2 impeded bone development through increasing Hif3a expression in DA2B mice.

PubMed

Zhu, Xiaoquan; Wang, Fengchao; Zhao, Yanyang; Yang, Peng; Chen, Jun; Sun, Hanzi; Liu, Lei; Li, Wenjun; Pan, Lin; Guo, Yanru; Kou, Zhaohui; Zhang, Yu; Zhou, Cheng; He, Jiang; Zhang, Xue; Li, Jianxin; Han, Weitian; Li, Jian; Liu, Guanghui; Gao, Shaorong; Yang, Ze

2014-10-01

Distal arthrogryposis type 2B (DA2B) is an important genetic disorder in humans. However, the mechanisms governing this disease are not clearly understood. In this study, we generated knock-in mice carrying a DA2B mutation (K175del) in troponin I type 2 (skeletal, fast) (TNNI2), which encodes a fast-twitch skeletal muscle protein. Tnni2K175del mice (referred to as DA2B mice) showed typical DA2B phenotypes, including limb abnormality and small body size. However, the current knowledge concerning TNNI2 could not explain the small body phenotype of DA2B mice. We found that Tnni2 was expressed in the osteoblasts and chondrocytes of long bone growth plates. Expression profile analysis using radii and ulnae demonstrated that Hif3a expression was significantly increased in the Tnni2K175del mice. Chromatin immunoprecipitation assays indicated that both wild-type and mutant tnni2 protein can bind to the Hif3a promoter using mouse primary osteoblasts. Moreover, we showed that the mutant tnni2 protein had a higher capacity to transactivate Hif3a than the wild-type protein. The increased amount of hif3a resulted in impairment of angiogenesis, delay in endochondral ossification, and decrease in chondrocyte differentiation and osteoblast proliferation, suggesting that hif3a counteracted hif1a-induced Vegf expression in DA2B mice. Together, our data indicated that Tnni2K175del mutation led to abnormally increased hif3a and decreased vegf in bone, which explain, at least in part, the small body size of Tnni2K175del mice. Furthermore, our findings revealed a new function of tnni2 in the regulation of bone development, and the study of gain-of-function mutation in Tnni2 in transgenic mice opens a new avenue to understand the pathological mechanism of human DA2B disorder.

Partial Tmem106b reduction does not correct abnormalities due to progranulin haploinsufficiency.

PubMed

Arrant, Andrew E; Nicholson, Alexandra M; Zhou, Xiaolai; Rademakers, Rosa; Roberson, Erik D

2018-06-22

Loss of function mutations in progranulin (GRN) are a major cause of frontotemporal dementia (FTD). Progranulin is a secreted glycoprotein that localizes to lysosomes and is critical for proper lysosomal function. Heterozygous GRN mutation carriers develop FTD with TDP-43 pathology and exhibit signs of lysosomal dysfunction in the brain, with increased levels of lysosomal proteins and lipofuscin accumulation. Homozygous GRN mutation carriers develop neuronal ceroid lipofuscinosis (NCL), an earlier-onset lysosomal storage disorder caused by severe lysosomal dysfunction. Multiple genome-wide association studies have shown that risk of FTD in GRN mutation carriers is modified by polymorphisms in TMEM106B, which encodes a lysosomal membrane protein. Risk alleles of TMEM106B may increase TMEM106B levels through a variety of mechanisms. Brains from FTD patients with GRN mutations exhibit increased TMEM106B expression, and protective TMEM106B polymorphisms are associated with decreased TMEM106B expression. Together, these data raise the possibility that reduction of TMEM106B levels may protect against the pathogenic effects of progranulin haploinsufficiency. We crossed Tmem106b +/- mice with Grn +/- mice, which model the progranulin haploinsufficiency of GRN mutation carriers and develop age-dependent social deficits and lysosomal abnormalities in the brain. We tested whether partial Tmem106b reduction could normalize the social deficits and lysosomal abnormalities of Grn +/- mice. Partial reduction of Tmem106b levels did not correct the social deficits of Grn +/- mice. Tmem106b reduction also failed to normalize most lysosomal abnormalities of Grn +/- mice, except for β-glucuronidase activity, which was suppressed by Tmem106b reduction and increased by progranulin insufficiency. These data do not support the hypothesis that Tmem106b reduction protects against the pathogenic effects of progranulin haploinsufficiency, but do show that Tmem106b reduction normalizes some

Avoidance of APOBEC3B-induced mutation by error-free lesion bypass

PubMed Central

Hoopes, James I.; Hughes, Amber L.; Hobson, Lauren A.; Cortez, Luis M.; Brown, Alexander J.

2017-01-01

Abstract APOBEC cytidine deaminases mutate cancer genomes by converting cytidines into uridines within ssDNA during replication. Although uracil DNA glycosylases limit APOBEC-induced mutation, it is unknown if subsequent base excision repair (BER) steps function on replication-associated ssDNA. Hence, we measured APOBEC3B-induced CAN1 mutation frequencies in yeast deficient in BER endonucleases or DNA damage tolerance proteins. Strains lacking Apn1, Apn2, Ntg1, Ntg2 or Rev3 displayed wild-type frequencies of APOBEC3B-induced canavanine resistance (CanR). However, strains without error-free lesion bypass proteins Ubc13, Mms2 and Mph1 displayed respective 4.9-, 2.8- and 7.8-fold higher frequency of APOBEC3B-induced CanR. These results indicate that mutations resulting from APOBEC activity are avoided by deoxyuridine conversion to abasic sites ahead of nascent lagging strand DNA synthesis and subsequent bypass by error-free template switching. We found this mechanism also functions during telomere re-synthesis, but with a diminished requirement for Ubc13. Interestingly, reduction of G to C substitutions in Ubc13-deficient strains uncovered a previously unknown role of Ubc13 in controlling the activity of the translesion synthesis polymerase, Rev1. Our results highlight a novel mechanism for error-free bypass of deoxyuridines generated within ssDNA and suggest that the APOBEC mutation signature observed in cancer genomes may under-represent the genomic damage these enzymes induce. PMID:28334887

ANXA11 mutations prevail in Chinese ALS patients with and without cognitive dementia.

PubMed

Zhang, Kang; Liu, Qing; Liu, Keqiang; Shen, Dongchao; Tai, Hongfei; Shu, Shi; Ding, Qingyun; Fu, Hanhui; Liu, Shuangwu; Wang, Zhili; Li, Xiaoguang; Liu, Mingsheng; Zhang, Xue; Cui, Liying

2018-06-01

To investigate the genetic contribution of ANXA11 , a gene associated with amyotrophic lateral sclerosis (ALS), in Chinese ALS patients with and without cognitive dementia. Sequencing all the coding exons of ANXA11 and intron-exon boundaries in 18 familial amyotrophic lateral sclerosis (FALS), 353 unrelated sporadic amyotrophic lateral sclerosis (SALS), and 12 Chinese patients with ALS-frontotemporal lobar dementia (ALS-FTD). The transcripts in peripheral blood generated from a splicing mutation were examined by reverse transcriptase PCR. We identified 6 nonsynonymous heterozygous mutations (5 novel and 1 recurrent), 1 splice site mutation, and 1 deletion of 10 amino acids (not accounted in the mutant frequency) in 11 unrelated patients, accounting for a mutant frequency of 5.6% (1/18) in FALS, 2.3% (8/353) in SALS, and 8.3% (1/12) in ALS-FTD. The deletion of 10 amino acids was detected in 1 clinically undetermined male with an ALS family history who had atrophy in hand muscles and myotonic discharges revealed by EMG. The novel p. P36R mutation was identified in 1 FALS index, 1 patient with SALS, and 1 ALS-FTD. The splicing mutation (c.174-2A>G) caused in-frame skipping of the entire exon 6. The rest missense mutations including p.D40G, p.V128M, p.S229R, p.R302C and p.G491R were found in 6 unrelated patients with SALS. The ANXA11 gene is one of the most frequently mutated genes in Chinese patients with SALS. A canonical splice site mutation leading to skipping of the entire exon 6 further supports the loss-of-function mechanism. In addition, the study findings further expand the ANXA11 phenotype, first highlighting its pathogenic role in ALS-FTD.

C9orf72 BAC Mouse Model with Motor Deficits and Neurodegenerative Features of ALS/FTD.

PubMed

Liu, Yuanjing; Pattamatta, Amrutha; Zu, Tao; Reid, Tammy; Bardhi, Olgert; Borchelt, David R; Yachnis, Anthony T; Ranum, Laura P W

2016-05-04

To define how the C9orf72 GGGGCC expansion mutation causes ALS/FTD and to facilitate therapy development, a mouse model that recapitulates the molecular and phenotypic features of the disease is urgently needed. Two groups recently reported BAC mouse models that produce RNA foci and RAN proteins but, surprisingly, do not develop the neurodegenerative or behavioral features of ALS/FTD. We now report a BAC mouse model of C9orf72 ALS/FTD that shows decreased survival, paralysis, muscle denervation, motor neuron loss, anxiety-like behavior, and cortical and hippocampal neurodegeneration. These mice express C9orf72 sense transcripts and upregulated antisense transcripts. In contrast to sense RNA foci, antisense foci preferentially accumulate in ALS/FTD-vulnerable cell populations. RAN protein accumulation increases with age and disease, and TDP-43 inclusions are found in degenerating brain regions in end-stage animals. The ALS/FTD phenotypes in our mice provide a unique tool that will facilitate developing therapies targeting pathways that prevent neurodegeneration and increase survival. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic screening in sporadic ALS and FTD.

PubMed

Turner, Martin R; Al-Chalabi, Ammar; Chio, Adriano; Hardiman, Orla; Kiernan, Matthew C; Rohrer, Jonathan D; Rowe, James; Seeley, William; Talbot, Kevin

2017-12-01

The increasing complexity of the genetic landscape in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) presents a significant resource and physician training challenge. At least 10% of those diagnosed with ALS or FTD are known to carry an autosomal dominant genetic mutation. There is no consensus on what constitutes a positive family history, and ascertainment is unreliable for many reasons. However, symptomatic individuals often wish to understand as much as possible about the cause of their disease, and to share this knowledge with their family. While the right of an individual not to know is a key aspect of patient autonomy, and despite the absence of definitive therapy, many newly diagnosed individuals are likely to elect for genetic testing if offered. It is incumbent on the practitioner to ensure that they are adequately informed, counselled and supported in this decision. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Mutations in STT3A and STT3B cause two congenital disorders of glycosylation

PubMed Central

Shrimal, Shiteshu; Ng, Bobby G.; Losfeld, Marie-Estelle; Gilmore, Reid; Freeze, Hudson H.

2013-01-01

We describe two unreported types of congenital disorders of glycosylation (CDG) which are caused by mutations in different isoforms of the catalytic subunit of the oligosaccharyltransferase (OST). Each isoform is encoded by a different gene (STT3A or STT3B), resides in a different OST complex and has distinct donor and acceptor substrate specificities with partially overlapping functions in N-glycosylation. The two cases from unrelated consanguineous families both show neurologic abnormalities, hypotonia, intellectual disability, failure to thrive and feeding problems. A homozygous mutation (c.1877T > C) in STT3A causes a p.Val626Ala change and a homozygous intronic mutation (c.1539 + 20G > T) in STT3B causes the other disorder. Both mutations impair glycosylation of a GFP biomarker and are rescued with the corresponding cDNA. Glycosylation of STT3A- and STT3B-specific acceptors is decreased in fibroblasts carrying the corresponding mutated gene and expression of the STT3A (p.Val626Ala) allele in STT3A-deficient HeLa cells does not rescue glycosylation. No additional cases were found in our collection or in reviewing various databases. The STT3A mutation significantly impairs glycosylation of the biomarker transferrin, but the STT3B mutation only slightly affects its glycosylation. Additional cases of STT3B-CDG may be missed by transferrin analysis and will require exome or genome sequencing. PMID:23842455

Frontotemporal dementia: insights into the biological underpinnings of disease through gene co-expression network analysis.

PubMed

Ferrari, Raffaele; Forabosco, Paola; Vandrovcova, Jana; Botía, Juan A; Guelfi, Sebastian; Warren, Jason D; Momeni, Parastoo; Weale, Michael E; Ryten, Mina; Hardy, John

2016-02-24

In frontotemporal dementia (FTD) there is a critical lack in the understanding of biological and molecular mechanisms involved in disease pathogenesis. The heterogeneous genetic features associated with FTD suggest that multiple disease-mechanisms are likely to contribute to the development of this neurodegenerative condition. We here present a systems biology approach with the scope of i) shedding light on the biological processes potentially implicated in the pathogenesis of FTD and ii) identifying novel potential risk factors for FTD. We performed a gene co-expression network analysis of microarray expression data from 101 individuals without neurodegenerative diseases to explore regional-specific co-expression patterns in the frontal and temporal cortices for 12 genes (MAPT, GRN, CHMP2B, CTSC, HLA-DRA, TMEM106B, C9orf72, VCP, UBQLN2, OPTN, TARDBP and FUS) associated with FTD and we then carried out gene set enrichment and pathway analyses, and investigated known protein-protein interactors (PPIs) of FTD-genes products. Gene co-expression networks revealed that several FTD-genes (such as MAPT and GRN, CTSC and HLA-DRA, TMEM106B, and C9orf72, VCP, UBQLN2 and OPTN) were clustering in modules of relevance in the frontal and temporal cortices. Functional annotation and pathway analyses of such modules indicated enrichment for: i) DNA metabolism, i.e. transcription regulation, DNA protection and chromatin remodelling (MAPT and GRN modules); ii) immune and lysosomal processes (CTSC and HLA-DRA modules), and; iii) protein meta/catabolism (C9orf72, VCP, UBQLN2 and OPTN, and TMEM106B modules). PPI analysis supported the results of the functional annotation and pathway analyses. This work further characterizes known FTD-genes and elaborates on their biological relevance to disease: not only do we indicate likely impacted regional-specific biological processes driven by FTD-genes containing modules, but also do we suggest novel potential risk factors among the FTD

Mutations in POLR3A and POLR3B Encoding RNA Polymerase III Subunits Cause an Autosomal-Recessive Hypomyelinating Leukoencephalopathy

PubMed Central

Saitsu, Hirotomo; Osaka, Hitoshi; Sasaki, Masayuki; Takanashi, Jun-ichi; Hamada, Keisuke; Yamashita, Akio; Shibayama, Hidehiro; Shiina, Masaaki; Kondo, Yukiko; Nishiyama, Kiyomi; Tsurusaki, Yoshinori; Miyake, Noriko; Doi, Hiroshi; Ogata, Kazuhiro; Inoue, Ken; Matsumoto, Naomichi

2011-01-01

Congenital hypomyelinating disorders are a heterogeneous group of inherited leukoencephalopathies characterized by abnormal myelin formation. We have recently reported a hypomyelinating syndrome characterized by diffuse cerebral hypomyelination with cerebellar atrophy and hypoplasia of the corpus callosum (HCAHC). We performed whole-exome sequencing of three unrelated individuals with HCAHC and identified compound heterozygous mutations in POLR3B in two individuals. The mutations include a nonsense mutation, a splice-site mutation, and two missense mutations at evolutionally conserved amino acids. Using reverse transcription-PCR and sequencing, we demonstrated that the splice-site mutation caused deletion of exon 18 from POLR3B mRNA and that the transcript harboring the nonsense mutation underwent nonsense-mediated mRNA decay. We also identified compound heterozygous missense mutations in POLR3A in the remaining individual. POLR3A and POLR3B encode the largest and second largest subunits of RNA Polymerase III (Pol III), RPC1 and RPC2, respectively. RPC1 and RPC2 together form the active center of the polymerase and contribute to the catalytic activity of the polymerase. Pol III is involved in the transcription of small noncoding RNAs, such as 5S ribosomal RNA and all transfer RNAs (tRNA). We hypothesize that perturbation of Pol III target transcription, especially of tRNAs, could be a common pathological mechanism underlying POLR3A and POLR3B mutations. PMID:22036171

INPP4B promotes cell survival via SGK3 activation in NPM1-mutated leukemia.

PubMed

Jin, Hongjun; Yang, Liyuan; Wang, Lu; Yang, Zailin; Zhan, Qian; Tao, Yao; Zou, Qin; Tang, Yuting; Xian, Jingrong; Zhang, Shuaishuai; Jing, Yipei; Zhang, Ling

2018-01-17

Acute myeloid leukemia (AML) with mutated nucleophosmin (NPM1) has been recognized as a distinct leukemia entity in the 2016 World Health Organization (WHO) classification. The genetic events underlying oncogenesis in NPM1-mutated AML that is characterized by a normal karyotype remain unclear. Inositol polyphosphate 4-phosphatase type II (INPP4B), a new factor in the phosphoinositide-3 kinase (PI3K) pathway-associated cancers, has been recently found a clinically relevant role in AML. However, little is known about the specific mechanistic function of INPP4B in NPM1-mutated AML. The INPP4B expression levels in NPM1-mutated AML primary blasts and AML OCI-AML3 cell lines were determined by qRT-PCR and western blotting. The effect of INPP4B knockdown on OCI-AML3 leukemia cell proliferation was evaluated, using the Cell Counting Kit-8 and colony formation assay. After INPP4B overexpression or knockdown, the activation of serum and glucocorticoid-regulated kinase 3 (SGK3) and AKT was assessed. The effects of PI3K signaling pathway inhibitors on the levels of p-SGK3 in OCI-AML3 cells were tested. The mass of PI (3,4) P 2 and PI (3) P was analyzed by ELISA upon INPP4B overexpression. Knockdown of SGK3 by RNA interference and a rescue assay were performed to confirm the critical role of SGK3 in INPP4B-mediated cell survival. In addition, the molecular mechanism underlying INPP4B expression in NPM1-mutated leukemia cells was explored. Finally, Kaplan-Meier survival analysis was conducted on the NPM1-mutated AML cohort stratified into quartiles for INPP4B expression in The Cancer Genome Atlas (TCGA) dataset. High expression of INPP4B was observed in NPM1-mutated AML. Knockdown of INPP4B repressed cell proliferation in OCI-AML3 cells, whereas recovered INPP4B rescued this inhibitory effect in vitro. Mechanically, INPP4B enhanced phosphorylated SGK3 (p-SGK3) status, but did not affect AKT activation. SGK3 was required for INPP4B-induced cell proliferation in OCI-AML3 cells

Adaptation and validation of a Spanish-language version of the Frontotemporal Dementia Rating Scale (FTD-FRS).

PubMed

Turró-Garriga, O; Hermoso Contreras, C; Olives Cladera, J; Mioshi, E; Pelegrín Valero, C; Olivera Pueyo, J; Garre-Olmo, J; Sánchez-Valle, R

2017-06-01

The Frontotemporal Dementia Rating Scale (FTD-FRS) is a tool designed to aid with clinical staging and assessment of the progression of frontotemporal dementia (FTD-FRS). Present a multicentre adaptation and validation study of a Spanish version of the FRS. The adapted version was created using 2 translation-back translation processes (English to Spanish, Spanish to English) and verified by the scale's original authors. We validated the adapted version in a sample of consecutive patients diagnosed with FTD. The procedure included evaluating internal consistency, testing unidimensionality with the Rasch model, analysing construct validity and discriminant validity, and calculating the degree of agreement between the Clinical Dementia Rating scale (CDR) and FTD-FRS for FTD cases. The study included 60 patients with DFT. The mean score on the FRS was 12.1 points (SD=6.5; range, 2-25) with inter-group differences (F=120.3; df=3; P<.001). Cronbach's alpha was 0.897 and principal component analysis of residuals delivered an acceptable eigenvalue for 5 contrasts (1.6-2.7) and 36.1% raw variance. FRS was correlated with the Mini-mental State Examination (r=0.572; P<.001) and functional capacity (DAD; r=0.790; P<.001). FTD-FRS also showed a significant correlation with CDR (r=-0.641; P<.001), but we did observe variability in the severity levels; cases appeared to be less severe according to the CDR than when measured with the FTD-FRS (kappa=0.055). This process of validating the Spanish translation of the FTD-FRS yielded satisfactory results for validity and unidimensionality (severity) in the assessment of patients with FTD. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

SF3B1 and BAP1 mutations in blue nevus-like melanoma.

PubMed

Griewank, Klaus G; Müller, Hansgeorg; Jackett, Louise A; Emberger, Michael; Möller, Inga; van de Nes, Johannes Ap; Zimmer, Lisa; Livingstone, Elisabeth; Wiesner, Thomas; Scholz, Simone L; Cosgarea, Ioana; Sucker, Antje; Schimming, Tobias; Hillen, Uwe; Schilling, Bastian; Paschen, Annette; Reis, Henning; Mentzel, Thomas; Kutzner, Heinz; Rütten, Arno; Murali, Rajmohan; Scolyer, Richard A; Schadendorf, Dirk

2017-07-01

Blue nevi are melanocytic tumors originating in the cutaneous dermis. Malignant tumors may arise in association with or resembling blue nevi, so called 'blue nevus-like melanoma', which can metastasize and result in patient death. Identifying which tumors will behave in a clinically aggressive manner can be challenging. Identifying genetic alterations in such tumors may assist in their diagnosis and prognostication. Blue nevi are known to be genetically related to uveal melanomas (eg, both harboring GNAQ and GNA11 mutations). In this study, we analyzed a large cohort (n=301) of various morphologic variants of blue nevi and related tumors including tumors diagnosed as atypical blue nevi (n=21), and blue nevus-like melanoma (n=12), screening for all gene mutations known to occur in uveal melanoma. Similar to published reports, we found the majority of blue nevi harbored activating mutations in GNAQ (53%) or GNA11 (15%). In addition, rare CYSLTR2 (1%) and PLCB4 (1%) mutations were identified. EIF1AX, SF3B1, and BAP1 mutations were also detected, with BAP1 and SF3B1 R625 mutations being present only in clearly malignant tumors (17% (n=2) and 25% (n=3) of blue nevus-like melanoma, respectively). In sequencing data from a larger cohort of cutaneous melanomas, this genetic profile was also identified in tumors not originally diagnosed as blue nevus-like melanoma. Our findings suggest that the genetic profile of coexistent GNAQ or GNA11 mutations with BAP1 or SF3B1 mutations can aid the histopathological diagnosis of blue nevus-like melanoma and distinguish blue nevus-like melanoma from conventional epidermal-derived melanomas. Future studies will need to further elucidate the prognostic implications and appropriate clinical management for patients with tumors harboring these mutation profiles.

A fresh perspective on comparing the FDA and the CHMP/EMA: approval of antineoplastic tyrosine kinase inhibitors

PubMed Central

Shah, Rashmi R; Roberts, Samantha A; Shah, Devron R

2013-01-01

We compared and determined the reasons for any differences in the review and approval times of tyrosine kinase inhibitors (TKIs) by the US Food and Drug Administration (FDA) and the European EMA/CHMP. Applications for these novel cancer drugs were submitted to them within a mean of 31.2 days of each other, providing a fair basis for comparison. The FDA had granted priority review to 12 TKIs but the EMA/CHMP did not grant the equivalent accelerated assessment to any. The FDA granted accelerated approvals to six (38%) and CHMP granted (the equivalent) conditional approvals to four (29%) of these agents. On average, the review and approval times were 205.3 days in the US compared with 409.6 days in the European Union (EU). The active review times, however, were comparable (225.4 days in the EU and 205.3 days in the US). Since oncology drug development lasts about 7 years, the 20 days difference in review times between the two agencies is inconsequential. Clock stops during review and the time required to issue an approval had added the extra 184.2 days to review time in the EU. We suggest possible solutions to expedite the EU review and approval processes. However, post-marketing emergence of adverse efficacy and safety data on gefitinib and lapatinib, respectively, indicate potential risks of expedited approvals. We challenge the widely prevalent myth that early approval translates into early access or beneficial impact on public health. Both the agencies collaborate closely but conduct independent assessments and make decisions based on distinct legislation, procedures, precedents and societal expectations. PMID:23362829

Genetic loss of SH2B3 in acute lymphoblastic leukemia.

PubMed

Perez-Garcia, Arianne; Ambesi-Impiombato, Alberto; Hadler, Michael; Rigo, Isaura; LeDuc, Charles A; Kelly, Kara; Jalas, Chaim; Paietta, Elisabeth; Racevskis, Janis; Rowe, Jacob M; Tallman, Martin S; Paganin, Maddalena; Basso, Giuseppe; Tong, Wei; Chung, Wendy K; Ferrando, Adolfo A

2013-10-03

The SH2B adaptor protein 3 (SH2B3) gene encodes a negative regulator of cytokine signaling with a critical role in the homeostasis of hematopoietic stem cells and lymphoid progenitors. Here, we report the identification of germline homozygous SH2B3 mutations in 2 siblings affected with developmental delay and autoimmunity, one in whom B-precursor acute lymphoblastic leukemia (ALL) developed. Mechanistically, loss of SH2B3 increases Janus kinase-signal transducer and activator of transcription signaling, promotes lymphoid cell proliferation, and accelerates leukemia development in a mouse model of NOTCH1-induced ALL. Moreover, extended mutation analysis showed homozygous somatic mutations in SH2B3 in 2 of 167 ALLs analyzed. Overall, these results demonstrate a Knudson tumor suppressor role for SH2B3 in the pathogenesis of ALL and highlight a possible link between genetic predisposition factors in the pathogenesis of autoimmunity and leukemogenesis.

SF3B1 mutations constitute a novel therapeutic target in breast cancer

PubMed Central

Maguire, Sarah L; Leonidou, Andri; Wai, Patty; Marchiò, Caterina; Ng, Charlotte KY; Sapino, Anna; Salomon, Anne-Vincent; Reis-Filho, Jorge S; Weigelt, Britta; Natrajan, Rachael C

2015-01-01

Mutations in genes encoding proteins involved in RNA splicing have been found to occur at relatively high frequencies in several tumour types including myelodysplastic syndromes, chronic lymphocytic leukaemia, uveal melanoma, and pancreatic cancer, and at lower frequencies in breast cancer. To investigate whether dysfunction in RNA splicing is implicated in the pathogenesis of breast cancer, we performed a re-analysis of published exome and whole genome sequencing data. This analysis revealed that mutations in spliceosomal component genes occurred in 5.6% of unselected breast cancers, including hotspot mutations in the SF3B1 gene, which were found in 1.8% of unselected breast cancers. SF3B1 mutations were significantly associated with ER-positive disease, AKT1 mutations, and distinct copy number alterations. Additional profiling of hotspot mutations in a panel of special histological subtypes of breast cancer showed that 16% and 6% of papillary and mucinous carcinomas of the breast harboured the SF3B1 K700E mutation. RNA sequencing identified differentially spliced events expressed in tumours with SF3B1 mutations including the protein coding genes TMEM14C, RPL31, DYNL11, UQCC, and ABCC5, and the long non-coding RNA CRNDE. Moreover, SF3B1 mutant cell lines were found to be sensitive to the SF3b complex inhibitor spliceostatin A and treatment resulted in perturbation of the splicing signature. Albeit rare, SF3B1 mutations result in alternative splicing events, and may constitute drivers and a novel therapeutic target in a subset of breast cancers. © 2014 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. PMID:25424858

Mutations in the PP2A regulatory subunit B family genes PPP2R5B, PPP2R5C and PPP2R5D cause human overgrowth.

PubMed

Loveday, Chey; Tatton-Brown, Katrina; Clarke, Matthew; Westwood, Isaac; Renwick, Anthony; Ramsay, Emma; Nemeth, Andrea; Campbell, Jennifer; Joss, Shelagh; Gardner, McKinlay; Zachariou, Anna; Elliott, Anna; Ruark, Elise; van Montfort, Rob; Rahman, Nazneen

2015-09-01

Overgrowth syndromes comprise a group of heterogeneous disorders characterised by excessive growth parameters, often in association with intellectual disability. To identify new causes of human overgrowth, we have been undertaking trio-based exome sequencing studies in overgrowth patients and their unaffected parents. Prioritisation of functionally relevant genes with multiple unique de novo mutations revealed four mutations in protein phosphatase 2A (PP2A) regulatory subunit B family genes protein phosphatase 2, regulatory Subunit B', beta (PPP2R5B); protein phosphatase 2, regulatory Subunit B', gamma (PPP2R5C); and protein phosphatase 2, regulatory Subunit B', delta (PPP2R5D). This observation in 3 related genes in 111 individuals with a similar phenotype is greatly in excess of the expected number, as determined from gene-specific de novo mutation rates (P = 1.43 × 10(-10)). Analysis of exome-sequencing data from a follow-up series of overgrowth probands identified a further pathogenic mutation, bringing the total number of affected individuals to 5. Heterozygotes shared similar phenotypic features including increased height, increased head circumference and intellectual disability. The mutations clustered within a region of nine amino acid residues in the aligned protein sequences (P = 1.6 × 10(-5)). We mapped the mutations onto the crystal structure of the PP2A holoenzyme complex to predict their molecular and functional consequences. These studies suggest that the mutations may affect substrate binding, thus perturbing the ability of PP2A to dephosphorylate particular protein substrates. PP2A is a major negative regulator of v-akt murine thymoma viral oncogene homolog 1 (AKT). Thus, our data further expand the list of genes encoding components of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT signalling cascade that are disrupted in human overgrowth conditions. © The Author 2015. Published by Oxford University Press.

Identify mutation in amyotrophic lateral sclerosis cases using HaloPlex target enrichment system.

PubMed

Liu, Zhi-Jun; Li, Hong-Fu; Tan, Guo-He; Tao, Qing-Qing; Ni, Wang; Cheng, Xue-Wen; Xiong, Zhi-Qi; Wu, Zhi-Ying

2014-12-01

To date, at least 18 causative genes have been identified in amyotrophic lateral sclerosis (ALS). Because of the clinical and genetic heterogeneity, molecular diagnosis for ALS faces great challenges. HaloPlex target enrichment system is a new targeted sequencing approach, which can detect already known mutations or candidate genes. We performed this approach to screen 18 causative genes of ALS, including SOD1, SETX, FUS, ANG, TARDBP, ALS2, FIG4, VAPB, OPTN, DAO, VCP, UBQLN2, SPG11, SIGMAR1, DCTN1, SQSTM1, PFN1, and CHMP2B in 8 ALS probands. Using this approach, we got an average of 9.5 synonymous or missense mutations per sample. After validation by Sanger sequencing, we identified 3 documented SOD1 mutations (p.F21C, p.G148D, and p.C147R) and 1 novel DCTN1 p.G59R mutation in 4 probands. The novel DCTN1 mutation appeared to segregate with the disease in the pedigree and was absent in 200 control subjects. The high throughput and efficiency of this approach indicated that it could be applied to diagnose ALS and other inherited diseases with multiple causative genes in clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

Mutations in SULT2B1 Cause Autosomal-Recessive Congenital Ichthyosis in Humans.

PubMed

Heinz, Lisa; Kim, Gwang-Jin; Marrakchi, Slaheddine; Christiansen, Julie; Turki, Hamida; Rauschendorf, Marc-Alexander; Lathrop, Mark; Hausser, Ingrid; Zimmer, Andreas D; Fischer, Judith

2017-06-01

Ichthyoses are a clinically and genetically heterogeneous group of genodermatoses associated with abnormal scaling of the skin over the whole body. Mutations in nine genes are known to cause non-syndromic forms of autosomal-recessive congenital ichthyosis (ARCI). However, not all genetic causes for ARCI have been discovered to date. Using whole-exome sequencing (WES) and multigene panel screening, we identified 6 ARCI-affected individuals from three unrelated families with mutations in Sulfotransferase family 2B member 1 (SULT2B1), showing their causative association with ARCI. Cytosolic sulfotransferases form a large family of enzymes that are involved in the synthesis and metabolism of several steroids in humans. We identified four distinct mutations including missense, nonsense, and splice site mutations. We demonstrated the loss of SULT2B1 expression at RNA and protein levels in keratinocytes from individuals with ARCI by functional analyses. Furthermore, we succeeded in reconstructing the morphologic skin alterations in a 3D organotypic tissue culture model with SULT2B1-deficient keratinocytes and fibroblasts. By thin layer chromatography (TLC) of extracts from these organotypic cultures, we could show the absence of cholesterol sulfate, the metabolite of SULT2B1, and an increased level of cholesterol, indicating a disturbed cholesterol metabolism of the skin upon loss-of-function mutation in SULT2B1. In conclusion, our study reveals an essential role for SULT2B1 in the proper development of healthy human skin. Mutation in SULT2B1 leads to an ARCI phenotype via increased proliferation of human keratinocytes, thickening of epithelial layers, and altered epidermal cholesterol metabolism. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Disturbance of proteasomal and autophagic protein degradation pathways by amyotrophic lateral sclerosis-linked mutations in ubiquilin 2.

PubMed

Osaka, Mayuko; Ito, Daisuke; Suzuki, Norihiro

2016-04-01

Ubiquilin (UBQLN), a member of the ubiquitin-like (UBL)-ubiquitin-associated (UBA) family, is a dual regulator of both the proteasomal and autophagic branches of the cellular protein degradation system. Mutations in the UBQLN2 gene encoding ubiquilin 2 cause X-linked amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD), and UBQLN2-positive inclusions have been identified in ALS patients with UBQLN2 mutations as well as in cases of both familial and sporadic ALS without UBQLN2 mutations. Compelling evidence links UBQLN2 to disturbance of the protein quality control network in neurons, but the pathomechanisms remain obscure. This study aimed to clarify how ALS-linked mutations in UBQLN2 affect the protein degradation system. Overexpression of a UBQLN2 with ALS-associated mutations resulted in the accumulation of polyubiquitinated proteins in neuronal cells, including the ALS-associated protein TDP-43. This effect was dependent on the UBA domain but not on inclusion formation. Immunocytochemistry and protein fractionation analysis of IVm-UBQLN2 cellular distribution indicated that it sequesters ubiquitinated substrates from both the proteasomal and autophagic branches of the protein degradation system, resulting in accumulation of polyubiquitinated substrates. These findings provide a molecular basis for the development of ALS/FTD-associated proteinopathy and establish novel therapeutic targets for ALS. Copyright © 2016. Published by Elsevier Inc.

BAG3 Directly Interacts with Mutated alphaB-Crystallin to Suppress Its Aggregation and Toxicity

PubMed Central

Hishiya, Akinori; Salman, Mortada Najem; Carra, Serena; Kampinga, Harm H.; Takayama, Shinichi

2011-01-01

A homozygous disruption or genetic mutation of the bag3 gene causes progressive myofibrillar myopathy in mouse and human skeletal and cardiac muscle disorder while mutations in the small heat shock protein αB-crystallin gene (CRYAB) are reported to be responsible for myofibrillar myopathy. Here, we demonstrate that BAG3 directly binds to wild-type αB-crystallin and the αB-crystallin mutant R120G, via the intermediate domain of BAG3. Peptides that inhibit this interaction in an in vitro binding assay indicate that two conserved Ile-Pro-Val regions of BAG3 are involved in the interaction with αB-crystallin, which is similar to results showing BAG3 binding to HspB8 and HspB6. BAG3 overexpression increased αB-crystallin R120G solubility and inhibited its intracellular aggregation in HEK293 cells. BAG3 suppressed cell death induced by αB-crystallin R120G overexpression in differentiating C2C12 mouse myoblast cells. Our findings indicate a novel function for BAG3 in inhibiting protein aggregation caused by the genetic mutation of CRYAB responsible for human myofibrillar myopathy. PMID:21423662

Enhancement of B-cell receptor signaling by a point mutation of adaptor protein 3BP2 identified in human inherited disease cherubism.

PubMed

Ogi, Kazuhiro; Nakashima, Kenji; Chihara, Kazuyasu; Takeuchi, Kenji; Horiguchi, Tomoko; Fujieda, Shigeharu; Sada, Kiyonao

2011-09-01

Tyrosine phosphorylation of adaptor protein c-Abl-Src homology 3 (SH3) domain-binding protein-2 (3BP2, also referred to SH3BP2) positively regulates the B-cell antigen receptor (BCR)-mediated signal transduction, leading to the activation of nuclear factor of activated T cells (NFAT). Here we showed the effect of the proline to arginine substitution of 3BP2 in which is the most common mutation in patients with cherubism (P418R) on B-cell receptor signaling. Comparing to the wild type, overexpression of the mutant form of 3BP2 (3BP2-P416R, corresponding to P418R in human protein) enhanced BCR-mediated activation of NFAT. 3BP2-P416R increased the signaling complex formation with Syk, phospholipase C-γ2 (PLC-γ2), and Vav1. In contrast, 3BP2-P416R could not change the association with the negative regulator 14-3-3. Loss of the association mutant that was incapable to associate with 14-3-3 could not mimic BCR-mediated NFAT activation in Syk-deficient cells. Moreover, BCR-mediated phosphorylation of extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was not affected by P416R mutation. These results showed that P416R mutation of 3BP2 causes the gain of function in B cells by increasing the interaction with specific signaling molecules. © 2011 The Authors. Journal compilation © 2011 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

NEK1 genetic variability in a Belgian cohort of ALS and ALS-FTD patients.

PubMed

Nguyen, Hung Phuoc; Van Mossevelde, Sara; Dillen, Lubina; De Bleecker, Jan L; Moisse, Matthieu; Van Damme, Philip; Van Broeckhoven, Christine; van der Zee, Julie

2018-01-01

We evaluated the genetic impact of the amyotrophic lateral sclerosis (ALS) risk gene never in mitosis gene a-related kinase 1 (NEK1) in a Belgian cohort of 278 patients with ALS (n = 245) or ALS with frontotemporal dementia (ALS-FTD, n = 33) and 609 control individuals. We identified 2 ALS patients carrying a loss-of-function (LOF) mutation, p.Leu854Tyrfs*2 and p.Tyr871Valfs*17, that was absent in the control group. A third LOF variant p.Ser1036* was present in 2 sibs with familial ALS but also in an unrelated control person. Missense variants were common in both patients (3.6%) and controls (3.0%). The missense variant, p.Arg261His, which was previously associated with ALS risk, was detected with a minor allele frequency of 0.90% in patients compared to 0.33% in controls. Taken together, NEK1 LOF variants accounted for 1.1% of patients, although interpretation of pathogenicity and penetrance is complicated by the observation of occasional LOF variants in unaffected individuals (0.16%). Furthermore, enrichment of additional ALS gene mutations was observed in NEK1 carriers, suggestive of a "second hit" model were NEK1 variants may modify disease presentation of driving mutations. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

APOBEC3B upregulation and genomic mutation patterns in serous ovarian carcinoma

PubMed Central

Leonard, Brandon; Hart, Steven N.; Burns, Michael B.; Carpenter, Michael A.; Temiz, Nuri A.; Rathore, Anurag; Vogel, Rachel Isaksson; Nikas, Jason B.; Law, Emily K.; Brown, William L.; Li, Ying; Zhang, Yuji; Maurer, Matthew J.; Oberg, Ann L.; Cunningham, Julie M.; Shridhar, Viji; Bell, Debra A.; April, Craig; Bentley, David; Bibikova, Marina; Cheetham, R. Keira; Fan, Jian-Bing; Grocock, Russell; Humphray, Sean; Kingsbury, Zoya; Peden, John; Chien, Jeremy; Swisher, Elizabeth M.; Hartmann, Lynn C.; Kalli, Kimberly R.; Goode, Ellen L.; Sicotte, Hugues; Kaufmann, Scott H.; Harris, Reuben S.

2013-01-01

Ovarian cancer is a clinically and molecularly heterogeneous disease. The driving forces behind this variability are unknown. Here we report wide variation in expression of the DNA cytosine deaminase APOBEC3B, with elevated expression in a majority of ovarian cancer cell lines (3 standard deviations above the mean of normal ovarian surface epithelial cells) and high grade primary ovarian cancers. APOBEC3B is active in the nucleus of several ovarian cancer cell lines and elicits a biochemical preference for deamination of cytosines in 5′TC dinucleotides. Importantly, examination of whole-genome sequence from 16 ovarian cancers reveals that APOBEC3B expression correlates with total mutation load as well as elevated levels of transversion mutations. In particular, high APOBEC3B expression correlates with C-to-A and C-to-G transversion mutations within 5′TC dinucleotide motifs in early-stage high grade serous ovarian cancer genomes, suggesting that APOBEC3B-catalyzed genomic uracil lesions are further processed by downstream DNA ‘repair’ enzymes including error-prone translesion polymerases. These data identify a potential role for APOBEC3B in serous ovarian cancer genomic instability. PMID:24154874

Mitochondrial DNA depletion syndrome due to mutations in the RRM2B gene.

PubMed

Bornstein, Belén; Area, Estela; Flanigan, Kevin M; Ganesh, Jaya; Jayakar, Parul; Swoboda, Kathryn J; Coku, Jorida; Naini, Ali; Shanske, Sara; Tanji, Kurenai; Hirano, Michio; DiMauro, Salvatore

2008-06-01

Mitochondrial DNA depletion syndrome (MDS) is characterized by a reduction in mtDNA copy number and has been associated with mutations in eight nuclear genes, including enzymes involved in mitochondrial nucleotide metabolism (POLG, TK2, DGUOK, SUCLA2, SUCLG1, PEO1) and MPV17. Recently, mutations in the RRM2B gene, encoding the p53-controlled ribonucleotide reductase subunit, have been described in seven infants from four families, who presented with various combinations of hypotonia, tubulopathy, seizures, respiratory distress, diarrhea, and lactic acidosis. All children died before 4 months of age. We sequenced the RRM2B gene in three unrelated cases with unexplained severe mtDNA depletion. The first patient developed intractable diarrhea, profound weakness, respiratory distress, and died at 3 months. The other two unrelated patients had a much milder phenotype and are still alive at ages 27 and 36 months. All three patients had lactic acidosis and severe depletion of mtDNA in muscle. Muscle histochemistry showed RRF and COX deficiency. Sequencing the RRM2B gene revealed three missense mutations and two single nucleotide deletions in exons 6, 8, and 9, confirming that RRM2B mutations are important causes of MDS and that the clinical phenotype is heterogeneous and not invariably fatal in infancy.

CC2D1A and CC2D1B regulate degradation and signaling of EGFR and TLR4.

PubMed

Deshar, Rakesh; Cho, Eun-Bee; Yoon, Sungjoo Kim; Yoon, Jong-Bok

2016-11-11

Signaling through many transmembrane receptors is terminated by their sorting to the intraluminal vesicles (ILVs) of multivescular bodies (MVBs) and subsequent lysosomal degradation. ILV formation requires the endosomal sorting complex required for transport (ESCRT) machinery. CC2D1A and CC2D1B interact with the CHMP4 family of proteins, the major subunit of the ESCRT-III complex, however, their roles in receptor degradation and signaling are poorly defined. Here, we report that CC2D1A binds to CHMP4B polymers formed on endosomes to regulate the endosomal sorting pathway. We show that depletion of CC2D1A and B accelerates degradation of EGFR and elicits rapid termination of its downstream signaling through ERK1 and 2. Depletion of CC2D1A and B promotes sorting of EGFR to ILV leading to its rapid lysosomal degradation. In addition, we show that knockdown of CC2D1A and B has similar effects on degradation and downstream signaling of another membrane receptor, TLR4. Thus, these findings suggest that CC2D1A and B may have broad effects on transmembrane receptors by preventing premature ILV sorting and termination of signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

De novo design of RNA-binding proteins with a prion-like domain related to ALS/FTD proteinopathies.

PubMed

Mitsuhashi, Kana; Ito, Daisuke; Mashima, Kyoko; Oyama, Munenori; Takahashi, Shinichi; Suzuki, Norihiro

2017-12-04

Aberrant RNA-binding proteins form the core of the neurodegeneration cascade in spectrums of disease, such as amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). Six ALS-related molecules, TDP-43, FUS, TAF15, EWSR1, heterogeneous nuclear (hn)RNPA1 and hnRNPA2 are RNA-binding proteins containing candidate mutations identified in ALS patients and those share several common features, including harboring an aggregation-prone prion-like domain (PrLD) containing a glycine/serine-tyrosine-glycine/serine (G/S-Y-G/S)-motif-enriched low-complexity sequence and rich in glutamine and/or asparagine. Additinally, these six molecules are components of RNA granules involved in RNA quality control and become mislocated from the nucleus to form cytoplasmic inclusion bodies (IBs) in the ALS/FTD-affected brain. To reveal the essential mechanisms involved in ALS/FTD-related cytotoxicity associated with RNA-binding proteins containing PrLDs, we designed artificial RNA-binding proteins harboring G/S-Y-G/S-motif repeats with and without enriched glutamine residues and nuclear-import/export-signal sequences and examined their cytotoxicity in vitro. These proteins recapitulated features of ALS-linked molecules, including insoluble aggregation, formation of cytoplasmic IBs and components of RNA granules, and cytotoxicity instigation. These findings indicated that these artificial RNA-binding proteins mimicked features of ALS-linked molecules and allowed the study of mechanisms associated with gain of toxic functions related to ALS/FTD pathogenesis.

Progranulin mutation causes frontotemporal dementia in the Swedish Karolinska family.

PubMed

Chiang, Huei-Hsin; Rosvall, Lina; Brohede, Jesper; Axelman, Karin; Björk, Behnosh F; Nennesmo, Inger; Robins, Tiina; Graff, Caroline

2008-11-01

Frontotemporal dementia (FTD) is a neurodegenerative disease characterized by cognitive impairment, language dysfunction, and/or changes in personality. Recently it has been shown that progranulin (GRN) mutations can cause FTD as well as other neurodegenerative phenotypes. DNA from 30 family members, of whom seven were diagnosed with FTD, in the Karolinska family was available for GRN sequencing. Fibroblast cell mRNA from one affected family member and six control individuals was available for relative quantitative real-time polymerase chain reaction to investigate the effect of the mutation. Furthermore, the cDNA of an affected individual was sequenced. Clinical and neuropathologic findings of a previously undescribed family branch are presented. A frameshift mutation in GRN (g.102delC) was detected in all affected family members and absent in four unaffected family members older than 70 years. Real-time polymerase chain reaction data showed an approximately 50% reduction of GRN fibroblast mRNA in an affected individual. The mutated mRNA transcripts were undetectable by cDNA sequencing. Segregation and RNA analyses showed that the g.102delC mutation, previously reported, causes FTD in the Karolinska family. Our findings add further support to the significance of GRN in FTD etiology and the presence of modifying genes, which emphasize the need for further studies into the mechanisms of clinical heterogeneity. However, the results already call for attention to the complexity of predictive genetic testing of GRN mutations.

Evidence for a role of the rare p.A152T variant in MAPT in increasing the risk for FTD-spectrum and Alzheimer's diseases

PubMed Central

Coppola, Giovanni; Chinnathambi, Subashchandrabose; Lee, Jason JiYong; Dombroski, Beth A.; Baker, Matt C.; Soto-Ortolaza, Alexandra I.; Lee, Suzee E.; Klein, Eric; Huang, Alden Y.; Sears, Renee; Lane, Jessica R.; Karydas, Anna M.; Kenet, Robert O.; Biernat, Jacek; Wang, Li-San; Cotman, Carl W.; DeCarli, Charles S.; Levey, Allan I.; Ringman, John M.; Mendez, Mario F.; Chui, Helena C.; Le Ber, Isabelle; Brice, Alexis; Lupton, Michelle K.; Preza, Elisavet; Lovestone, Simon; Powell, John; Graff-Radford, Neill; Petersen, Ronald C.; Boeve, Bradley F.; Lippa, Carol F.; Bigio, Eileen H.; Mackenzie, Ian; Finger, Elizabeth; Kertesz, Andrew; Caselli, Richard J.; Gearing, Marla; Juncos, Jorge L.; Ghetti, Bernardino; Spina, Salvatore; Bordelon, Yvette M.; Tourtellotte, Wallace W.; Frosch, Matthew P.; Vonsattel, Jean Paul G.; Zarow, Chris; Beach, Thomas G.; Albin, Roger L.; Lieberman, Andrew P.; Lee, Virginia M.; Trojanowski, John Q.; Van Deerlin, Vivianna M.; Bird, Thomas D.; Galasko, Douglas R.; Masliah, Eliezer; White, Charles L.; Troncoso, Juan C.; Hannequin, Didier; Boxer, Adam L.; Geschwind, Michael D.; Kumar, Satish; Mandelkow, Eva-Maria; Wszolek, Zbigniew K.; Uitti, Ryan J.; Dickson, Dennis W.; Haines, Jonathan L.; Mayeux, Richard; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Ross, Owen A.; Rademakers, Rosa; Schellenberg, Gerard D.; Miller, Bruce L.; Mandelkow, Eckhard; Geschwind, Daniel H.

2012-01-01

Rare mutations in the gene encoding for tau (MAPT, microtubule-associated protein tau) cause frontotemporal dementia-spectrum (FTD-s) disorders, including FTD, progressive supranuclear palsy (PSP) and corticobasal syndrome, and a common extended haplotype spanning across the MAPT locus is associated with increased risk of PSP and Parkinson's disease. We identified a rare tau variant (p.A152T) in a patient with a clinical diagnosis of PSP and assessed its frequency in multiple independent series of patients with neurodegenerative conditions and controls, in a total of 15 369 subjects. Tau p.A152T significantly increases the risk for both FTD-s (n = 2139, OR = 3.0, CI: 1.6–5.6, P = 0.0005) and Alzheimer's disease (AD) (n = 3345, OR = 2.3, CI: 1.3–4.2, P = 0.004) compared with 9047 controls. Functionally, p.A152T (i) decreases the binding of tau to microtubules and therefore promotes microtubule assembly less efficiently; and (ii) reduces the tendency to form abnormal fibers. However, there is a pronounced increase in the formation of tau oligomers. Importantly, these findings suggest that other regions of the tau protein may be crucial in regulating normal function, as the p.A152 residue is distal to the domains considered responsible for microtubule interactions or aggregation. These data provide both the first genetic evidence and functional studies supporting the role of MAPT p.A152T as a rare risk factor for both FTD-s and AD and the concept that rare variants can increase the risk for relatively common, complex neurodegenerative diseases, but since no clear significance threshold for rare genetic variation has been established, some caution is warranted until the findings are further replicated. PMID:22556362

Disease progression in C9orf72 mutation carriers.

PubMed

Floeter, Mary K; Traynor, Bryan J; Farren, Jennifer; Braun, Laura E; Tierney, Michael; Wiggs, Edythe A; Wu, Tianxia

2017-07-18

To assess changes in 3 clinical measures, the Revised ALS Functional Rating Scale (ALSFRS-R), letter fluency, and Frontal Behavioral Inventory (FBI), over time in C9orf72 mutation carriers (C9+) with varied clinical phenotypes. Thirty-four unrelated participants with mutations in C9orf72 were enrolled in a prospective natural history study. Participants were classified as asymptomatic, amyotrophic lateral sclerosis (ALS), ALS-familial frontotemporal dementia (FTD), or behavioral-variant FTD by clinical diagnostic criteria. Diagnostic cognitive and motor tests were repeated at 6 and 18 months. The ALSFRS-R, letter fluency, and FBI were administered at baseline and follow-up visits at 6, 12, and 18 months. The clinical diagnosis of most patients did not change over the follow-up. ALSFRS-R scores correlated with measures of motor function. Letter fluency correlated with FBI and cognitive tests. ALSFRS-R, letter fluency, and FBI differed among the C9+ diagnostic subgroups at enrollment and worsened over follow-up in symptomatic patients, with different slopes among the subgroups. Most patients survived to the 6-month time point after enrollment. Survival of C9+ patients with ALS and C9+ patients with ALS-FTD declined over the 12- and 18-month follow-up. The pattern of scores of the ALSFRS-R, letter fluency, and FBI distinguished between ALS, ALS-FTD, and FTD presentations of C9orf72 mutation carriers and asymptomatic carriers. Longitudinal changes in these measures occurred with disease progression in a manner consistent with presenting phenotype. © 2017 American Academy of Neurology.

CHMP6 and VPS4A mediate recycling of Ras to the plasma membrane to promote growth factor signaling

PubMed Central

Zheng, Ze-Yi; Cheng, Chiang-Min; Fu, Xin-Rong; Chen, Liuh-Yow; Xu, Lizhong; Terrillon, Sonia; Wong, Stephen T.; Bar-Sagi, Dafna; Songyang, Zhou; Chang, Eric C.

2011-01-01

While Ras is well-known to function on the plasma membrane (PM) to mediate growth factor signaling, increasing evidence suggests that Ras has complex roles in the cytoplasm. To uncover these roles, we screened a cDNA library and isolated H-Ras-binding proteins that also influence Ras functions. Many isolated proteins regulate trafficking involving endosomes; CHMP6/VPS20 and VPS4A, which interact with ESCRT-III, were chosen for further study. We showed that the binding is direct and occurs in endosomes. Furthermore, the binding is most efficient when H-Ras has a functional effector-binding-loop and is GTP-bound and ubiquitylated. CHMP6 and VPS4A also bound N-Ras, but not K-Ras. Repressing CHMP6 and VPS4A blocked Ras-induced transformation, which correlated with inefficient Ras localization to the PM as measured by cell fractionation and photobleaching. Moreover, silencing CHMP6 and VPS4A also blocked EGFR recycling. These data suggest that Ras interacts with key ESCRT-III components to promote recycling of itself and EGFR back to the PM to create a positive feedback loop to enhance growth factor signaling. PMID:22231449

Neonatal-Onset Chronic Diarrhea Caused by Homozygous Nonsense WNT2B Mutations.

PubMed

O'Connell, Amy E; Zhou, Fanny; Shah, Manasvi S; Murphy, Quinn; Rickner, Hannah; Kelsen, Judith; Boyle, John; Doyle, Jefferson J; Gangwani, Bharti; Thiagarajah, Jay R; Kamin, Daniel S; Goldsmith, Jeffrey D; Richmond, Camilla; Breault, David T; Agrawal, Pankaj B

2018-06-04

Homozygous nonsense mutations in WNT2B were identified in three individuals from two unrelated families with severe, neonatal-onset osmotic diarrhea after whole-exome sequencing was performed on trios from the two families. Intestinal biopsy samples from affected individuals were used for histology and immunofluorescence and to generate enteroids ex vivo. Histopathologic evaluation demonstrated chronic inflammatory changes in the stomach, duodenum, and colon. Immunofluorescence demonstrated diminished staining for OLFM4, a marker for intestinal stem cells (ISCs). The enteroids generated from WNT2B-deficient intestinal epithelium could not be expanded and did not survive passage. Addition of CHIR-99021 (a GSK3A and GSK3B inhibitor and activator of canonical WNT/β-CATENIN signaling) could not rescue WNT2B-deficient enteroids. Addition of supplemental recombinant murine WNT2B was able to perpetuate small enteroids for multiple passages but failed to expand their number. Enteroids showed a 10-fold increase in the expression of LEF1 mRNA and a 100-fold reduction in TLR4 expression, compared with controls by quantitative RT-PCR, indicating alterations in canonical WNT and microbial pattern-recognition signaling. In summary, individuals with homozygous nonsense mutations in WNT2B demonstrate severe intestinal dysregulation associated with decreased ISC number and function, likely explaining their diarrheal phenotype. WNT2B deficiency should be considered for individuals with neonatal-onset diarrhea. Copyright © 2018 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Intracellular Proteolysis of Progranulin Generates Stable, Lysosomal Granulins that Are Haploinsufficient in Patients with Frontotemporal Dementia Caused by GRN Mutations

PubMed Central

Taylor, Georgia; Deng, Qiudong

2017-01-01

Homozygous or heterozygous mutations in the GRN gene, encoding progranulin (PGRN), cause neuronal ceroid lipofuscinosis (NCL) or frontotemporal dementia (FTD), respectively. NCL and FTD are characterized by lysosome dysfunction and neurodegeneration, indicating PGRN is important for lysosome homeostasis in the brain. PGRN is trafficked to the lysosome where its functional role is unknown. PGRN can be cleaved into seven 6-kDa proteins called granulins (GRNs); however, little is known about how GRNs are produced or if levels of GRNs are altered in FTD-GRN mutation carriers. Here, we report the identification and characterization of antibodies that reliably detect several human GRNs by immunoblot and immunocytochemistry. Using these tools, we find that endogenous GRNs are present within multiple cell lines and are constitutively produced. Further, extracellular PGRN is endocytosed and rapidly processed into stable GRNs within lysosomes. Processing of PGRN into GRNs is conserved between humans and mice and is modulated by sortilin expression and mediated by cysteine proteases (i.e. cathpesin L). Induced lysosome dysfunction caused by alkalizing agents or increased expression of transmembrane protein 106B (TMEM106B) inhibit processing of PGRN into GRNs. Finally, we find that multiple GRNs are haploinsufficient in primary fibroblasts and cortical brain tissue from FTD-GRN patients. Taken together, our findings raise the interesting possibility that GRNs carry out critical lysosomal functions and that loss of GRNs should be explored as an initiating factor in lysosomal dysfunction and neurodegeneration caused by GRN mutations. PMID:28828399

TET2 mutations in B cells of patients affected by angioimmunoblastic T-cell lymphoma.

PubMed

Schwartz, Friederike H; Cai, Qian; Fellmann, Eva; Hartmann, Sylvia; Mäyränpää, Mikko I; Karjalainen-Lindsberg, Marja-Liisa; Sundström, Christer; Scholtysik, René; Hansmann, Martin-Leo; Küppers, Ralf

2017-06-01

Angioimmunoblastic T-cell lymphomas (AITLs) frequently carry mutations in the TET2 and IDH2 genes. TET2 mutations represent early genetic lesions as they had already been detected in haematopoietic precursor cells of AITL patients. We show by analysis of whole-tissue sections and microdissected PD1 + cells that the frequency of TET2-mutated AITL is presumably even higher than reported (12/13 cases in our collection; 92%). In two-thirds of informative AITLs (6/9), a fraction of B cells was also TET2-mutated. Investigation of four AITLs by TET2 and IGHV gene sequencing of single microdissected B cells showed that between 10% and 60% of polyclonal B cells in AITL lymph nodes harboured the identical TET2 mutations of the respective T-cell lymphoma clone. Thus, TET2-mutated haematopoietic precursor cells in AITL patients not only give rise to the T-cell lymphoma but also generate a large population of mutated mature B cells. Future studies will show whether this is a reason why AITL patients frequently also develop B-cell lymphomas. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Individual Patient Diagnosis of AD and FTD via High-Dimensional Pattern Classification of MRI

PubMed Central

Davatzikos, C.; Resnick, S. M.; Wu, X.; Parmpi, P.; Clark, C. M.

2008-01-01

The purpose of this study is to determine the diagnostic accuracy of MRI-based high-dimensional pattern classification in differentiating between patients with Alzheimer’s Disease (AD), Frontotemporal Dementia (FTD), and healthy controls, on an individual patient basis. MRI scans of 37 patients with AD and 37 age-matched cognitively normal elderly individuals, as well as 12 patients with FTD and 12 age-matched cognitively normal elderly individuals, were analyzed using voxel-based analysis and high-dimensional pattern classification. Diagnostic sensitivity and specificity of spatial patterns of regional brain atrophy found to be characteristic of AD and FTD were determined via cross-validation and via split-sample methods. Complex spatial patterns of relatively reduced brain volumes were identified, including temporal, orbitofrontal, parietal and cingulate regions, which were predominantly characteristic of either AD or FTD. These patterns provided 100% diagnostic accuracy, when used to separate AD or FTD from healthy controls. The ability to correctly distinguish AD from FTD averaged 84.3%. All estimates of diagnostic accuracy were determined via cross-validation. In conclusion, AD- and FTD-specific patterns of brain atrophy can be detected with high accuracy using high-dimensional pattern classification of MRI scans obtained in a typical clinical setting. PMID:18474436

Interaction of ApoE3 and ApoE4 isoforms with an ITM2b/BRI2 mutation linked to the Alzheimer disease-like Danish dementia: Effects on learning and memory

PubMed Central

Biundo, Fabrizio; Ishiwari, Keita; Del Prete, Dolores; D’Adamio, Luciano

2015-01-01

Mutations in Amyloid β Precursor Protein (APP) and in genes that regulate APP processing – such as PSEN1/2 and ITM2b/BRI2 – cause familial dementia, such Familial Alzheimer disease (FAD), Familial Danish (FDD) and British (FBD) dementias. The ApoE gene is the major genetic risk factor for sporadic AD. Three major variants of ApoE exist in humans (ApoE2, ApoE3, and ApoE4), with the ApoE4 allele being strongly associated with AD. ITM2b/BRI2 is also a candidate regulatory node genes predicted to mediate the common patterns of gene expression shared by healthy ApoE4 carriers and late-onset AD patients not carrying ApoE4. This evidence provides a direct link between ITM2b/BRI2 and ApoE4. To test whether ApoE4 and pathogenic ITM2b/BRI2 interact to modulate learning and memory, we crossed a mouse carrying the ITM2b/BRI2 mutations that causes FDD knocked-in the endogenous mouse Itm2b/Bri2 gene (FDDKI mice) with human ApoE3 and ApoE4 targeted replacement mice. The resultant ApoE3, FDDKI/ApoE3, ApoE4, FDDKI/ApoE4 male mice were assessed longitudinally for learning and memory at 4, 6, 12, and 16– 17 months of age. The results showed that ApoE4-carrying mice displayed spatial working/short-term memory deficits relative to ApoE3-carrying mice starting in early middle age, while long-term spatial memory of ApoE4 mice was not adversely affected even at 16–17 months, and that the FDD mutation impaired working/short-term spatial memory in ApoE3-carrying mice and produced impaired long-term spatial memory in ApoE4-carrying mice in middle age. The present results suggest that the FDD mutation may differentially affect learning and memory in ApoE4 carriers and non-carriers. PMID:26528887

Interaction of ApoE3 and ApoE4 isoforms with an ITM2b/BRI2 mutation linked to the Alzheimer disease-like Danish dementia: Effects on learning and memory.

PubMed

Biundo, Fabrizio; Ishiwari, Keita; Del Prete, Dolores; D'Adamio, Luciano

2015-12-01

Mutations in Amyloid β Precursor Protein (APP) and in genes that regulate APP processing--such as PSEN1/2 and ITM2b/BRI2--cause familial dementia, such Familial Alzheimer disease (FAD), Familial Danish (FDD) and British (FBD) dementias. The ApoE gene is the major genetic risk factor for sporadic AD. Three major variants of ApoE exist in humans (ApoE2, ApoE3, and ApoE4), with the ApoE4 allele being strongly associated with AD. ITM2b/BRI2 is also a candidate regulatory node genes predicted to mediate the common patterns of gene expression shared by healthy ApoE4 carriers and late-onset AD patients not carrying ApoE4. This evidence provides a direct link between ITM2b/BRI2 and ApoE4. To test whether ApoE4 and pathogenic ITM2b/BRI2 interact to modulate learning and memory, we crossed a mouse carrying the ITM2b/BRI2 mutations that causes FDD knocked-in the endogenous mouse Itm2b/Bri2 gene (FDDKI mice) with human ApoE3 and ApoE4 targeted replacement mice. The resultant ApoE3, FDDKI/ApoE3, ApoE4, FDDKI/ApoE4 male mice were assessed longitudinally for learning and memory at 4, 6, 12, and 16-17 months of age. The results showed that ApoE4-carrying mice displayed spatial working/short-term memory deficits relative to ApoE3-carrying mice starting in early middle age, while long-term spatial memory of ApoE4 mice was not adversely affected even at 16-17 months, and that the FDD mutation impaired working/short-term spatial memory in ApoE3-carrying mice and produced impaired long-term spatial memory in ApoE4-carrying mice in middle age. The present results suggest that the FDD mutation may differentially affect learning and memory in ApoE4 carriers and non-carriers. Copyright © 2015 Elsevier Inc. All rights reserved.

Mutations in POLR3A and POLR3B are a major cause of hypomyelinating leukodystrophies with or without dental abnormalities and/or hypogonadotropic hypogonadism.

PubMed

Daoud, Hussein; Tétreault, Martine; Gibson, William; Guerrero, Kether; Cohen, Ana; Gburek-Augustat, Janina; Synofzik, Matthis; Brais, Bernard; Stevens, Cathy A; Sanchez-Carpintero, Rocio; Goizet, Cyril; Naidu, Sakkubai; Vanderver, Adeline; Bernard, Geneviève

2013-03-01

Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterised by abnormal central nervous system white matter. Mutations in POLR3A and POLR3B genes were recently reported to cause four clinically overlapping hypomyelinating leukodystrophy phenotypes. Our aim was to investigate the presence and frequency of POLR3A and POLR3B mutations in patients with genetically unexplained hypomyelinating leukodystrophies with typical clinical and/or radiologic features of Pol III-related leukodystrophies. The entire coding region and the flanking exon/intron boundaries of POLR3A and/or POLR3B genes were amplified and sequenced in 14 patients. Recessive mutations in POLR3A or POLR3B were uncovered in all 14 patients. Eight novel mutations were identified in POLR3A: six missenses, one nonsense, and one frameshift mutation. Seven patients carried compound heterozygous mutations in POLR3B, of whom six shared the common mutation in exon 15 (p.V523E). Seven novel mutations were identified in POLR3B: four missenses, two splice sites, and one intronic mutation. To date, our group has described 37 patients, of whom 27 have mutations in POLR3A and 10 in POLR3B, respectively. Altogether, our results further support the proposal that POLR3A and POLR3B mutations are a major cause of hypomyelinating leukodystrophies and suggest that POLR3A mutations are more frequent.

Characterization of an FTLD-PDB family with the coexistence of SQSTM1 mutation and hexanucleotide (G₄C₂) repeat expansion in C9orf72 gene.

PubMed

Almeida, Maria Rosário; Letra, Liliana; Pires, Paula; Santos, Ana; Rebelo, Olinda; Guerreiro, Rita; van der Zee, Julie; Van Broeckhoven, Christine; Santana, Isabel

2016-04-01

The C9orf72 expansion is considered a major genetic cause of familial frontotemporal dementia (FTD) in several patients' cohorts. Interestingly, C9orf72 expansion carriers, present also abundant neuronal p62-positive inclusions. Although p62/SQSTM1 mutations were initially associated with Paget disease of bone (PDB), they have been also identified in FTD. We describe an FTD-PDB family in which the proband presented with behavioral FTD phenotype and concomitant Paget disease. The molecular genetic analysis revealed the co-occurrence of 2 mutations; the pathogenic C9orf72 expansion and p.P392L heterozygous missense mutation in SQSTM1 gene. Amongst the 6 family members analyzed, the p.P392L SQSTM1 mutation segregated as expected with PDB, whereas the C9orf72 expansion segregated with frontal cognitive impairment or dementia in all but one carrier. The coexistence of these conditions could be underestimated since neither patients with FTD nor patients with PDB undergo bone scintigraphy or cognitive assessment, respectively. The number of cases with double mutations could also be over looked as the molecular strategy adopted in most laboratories ends with the identification of one pathogenic mutation in one of the known causative genes. Therefore, we advocate for further clinical and molecular evaluation in suspect cases. Copyright © 2016 Elsevier Inc. All rights reserved.

A Novel MAPT Mutation, G55R, in a Frontotemporal Dementia Patient Leads to Altered Tau Function

PubMed Central

Guzman, Elmer; Barczak, Anna; Chodakowska-Żebrowska, Małgorzata; Barcikowska, Maria; Feinstein, Stuart

2013-01-01

Over two dozen mutations in the gene encoding the microtubule associated protein tau cause a variety of neurodegenerative dementias known as tauopathies, including frontotemporal dementia (FTD), PSP, CBD and Pick's disease. The vast majority of these mutations map to the C-terminal region of tau possessing microtubule assembly and microtubule dynamics regulatory activities as well as the ability to promote pathological tau aggregation. Here, we describe a novel and non-conservative tau mutation (G55R) mapping to an alternatively spliced exon encoding part of the N-terminal region of the protein in a patient with the behavioral variant of FTD. Although less well understood than the C-terminal region of tau, the N-terminal region can influence both MT mediated effects as well as tau aggregation. The mutation changes an uncharged glycine to a basic arginine in the midst of a highly conserved and very acidic region. In vitro, 4-repeat G55R tau nucleates microtubule assembly more effectively than wild-type 4-repeat tau; surprisingly, this effect is tau isoform specific and is not observed in a 3-repeat G55R tau versus 3-repeat wild-type tau comparison. In contrast, the G55R mutation has no effect upon the abilities of tau to regulate MT growing and shortening dynamics or to aggregate. Additionally, the mutation has no effect upon kinesin translocation in a microtubule gliding assay. Together, (i) we have identified a novel tau mutation mapping to a mutation deficient region of the protein in a bvFTD patient, and (ii) the G55R mutation affects the ability of tau to nucleate microtubule assembly in vitro in a 4-repeat tau isoform specific manner. This altered capability could markedly affect in vivo microtubule function and neuronal cell biology. We consider G55R to be a candidate mutation for bvFTD since additional criteria required to establish causality are not yet available for assessment. PMID:24086739

Two patients with Hermansky Pudlak syndrome type 2 and novel mutations in AP3B1

PubMed Central

Wenham, Matt; Grieve, Samantha; Cummins, Michelle; Jones, Matthew L.; Booth, Sarah; Kilner, Rachel; Ancliff, Philip J.; Griffiths, Gillian M.; Mumford, Andrew D.

2010-01-01

Hermansky Pudlak syndrome type 2 (HPS2) is a rare disorder associated with mutations in the Adaptor Protein 3 (AP-3) complex, which is involved in sorting transmembrane proteins to lysosomes and related organelles. We now report 2 unrelated subjects with HPS2 who show a characteristic clinical phenotype of oculocutaneous albinism, platelet and T-lymphocyte dysfunction and neutropenia. The subjects were homozygous for different deletions within AP3B1 (g.del180242-180866, c.del153-156), which encodes the AP-3β3A subunit, resulting in frame shifts and introduction of nonsense substitutions (p.E693fsX13, p.E52fsX11). In the subject with p.E693fsX13, this resulted in expression of a truncated variant β3A protein. Cytotoxic T-lymphocyte (CTL) clones from both study subjects showed increased cell-surface expression of CD63 and reduced cytotoxicity. Platelets showed impaired aggregation and reduced uptake of 3H-serotonin. These findings are consistent with CTL granule and platelet dense granule defects, respectively. This report extends the clinical and laboratory description of HPS2. PMID:19679886

Mutations in TP53 and JAK2 are independent prognostic biomarkers in B-cell precursor acute lymphoblastic leukaemia.

PubMed

Forero-Castro, Maribel; Robledo, Cristina; Benito, Rocío; Bodega-Mayor, Irene; Rapado, Inmaculada; Hernández-Sánchez, María; Abáigar, María; Maria Hernández-Sánchez, Jesús; Quijada-Álamo, Miguel; María Sánchez-Pina, José; Sala-Valdés, Mónica; Araujo-Silva, Fernanda; Kohlmann, Alexander; Luis Fuster, José; Arefi, Maryam; de Las Heras, Natalia; Riesco, Susana; Rodríguez, Juan N; Hermosín, Lourdes; Ribera, Jordi; Camos Guijosa, Mireia; Ramírez, Manuel; de Heredia Rubio, Cristina Díaz; Barragán, Eva; Martínez, Joaquín; Ribera, José M; Fernández-Ruiz, Elena; Hernández-Rivas, Jesús-María

2017-07-11

In B-cell precursor acute lymphoblastic leukaemia (B-ALL), the identification of additional genetic alterations associated with poor prognosis is still of importance. We determined the frequency and prognostic impact of somatic mutations in children and adult cases with B-ALL treated with Spanish PETHEMA and SEHOP protocols. Mutational status of hotspot regions of TP53, JAK2, PAX5, LEF1, CRLF2 and IL7R genes was determined by next-generation deep sequencing in 340 B-ALL patients (211 children and 129 adults). The associations between mutation status and clinicopathological features at the time of diagnosis, treatment outcome and survival were assessed. Univariate and multivariate survival analyses were performed to identify independent prognostic factors associated with overall survival (OS), event-free survival (EFS) and relapse rate (RR). A mutation rate of 12.4% was identified. The frequency of adult mutations was higher (20.2% vs 7.6%, P=0.001). TP53 was the most frequently mutated gene (4.1%), followed by JAK2 (3.8%), CRLF2 (2.9%), PAX5 (2.4%), LEF1 (0.6%) and IL7R (0.3%). All mutations were observed in B-ALL without ETV6-RUNX1 (P=0.047) or BCR-ABL1 fusions (P<0.0001). In children, TP53mut was associated with lower OS (5-year OS: 50% vs 86%, P=0.002) and EFS rates (5-year EFS: 50% vs 78.3%, P=0.009) and higher RR (5-year RR: 33.3% vs 18.6% P=0.037), and was independently associated with higher RR (hazard ratio (HR)=4.5; P=0.04). In adults, TP53mut was associated with a lower OS (5-year OS: 0% vs 43.3%, P=0.019) and a higher RR (5-year RR: 100% vs 61.4%, P=0.029), whereas JAK2mut was associated with a lower EFS (5-year EFS: 0% vs 30.6%, P=0.035) and a higher RR (5-year RR: 100% vs 60.4%, P=0.002). TP53mut was an independent risk factor for shorter OS (HR=2.3; P=0.035) and, together with JAK2mut, also were independent markers of poor prognosis for RR (TP53mut: HR=5.9; P=0.027 and JAK2mut: HR=5.6; P=0.036). TP53mut and JAK2mut are potential biomarkers associated

Modeling ALS and FTD with iPSC-derived Neurons

PubMed Central

Lee, Sebum; Huang, Eric J.

2015-01-01

Recent advances in genetics and neuropathology support the idea that amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTD) are two ends of a disease spectrum. Although several animal models have been developed to investigate the pathogenesis and disease progression in ALS and FTD, there are significant limitations that hamper our ability to connect these models with the neurodegenerative processes in human diseases. With the technical breakthrough in reprogramming biology, it is now possible to generate patient-specific induced pluripotent stem cells (iPSCs) and disease-relevant neuron subtypes. This review provides a comprehensive summary of studies that use iPSC-derived neurons to model ALS and FTD. We discuss the unique capabilities of iPSC-derived neurons that capture some key features of ALS and FTD, and underscore their potential roles in drug discovery. There are, however, several critical caveats that require improvements before iPSC-derived neurons can become highly effective disease models. PMID:26462653

MITOCHONDRIAL DNA DEPLETION SYNDROME DUE TO MUTATIONS IN THE RRM2B GENE

PubMed Central

Bornstein, Belén; Area, Estela; Flanigan, Kevin M.; Ganesh, Jaya; Jayakar, Parul; Swoboda, Kathryn J.; Coku, Jorida; Naini, Ali; Shanske, Sara; Tanji, Kurenai; Hirano, Michio; DiMauro, Salvatore

2014-01-01

Mitochondrial DNA depletion syndrome (MDS) is characterized by a reduction in mtDNA copy number and has been associated with mutations in eight nuclear genes, including enzymes involved in mitochondrial nucleotide metabolism (POLG, TK2, DGUOK, SUCLA2, SUCLG1, PEO1) and MPV17. Recently, mutations in The RRM2B gene, encoding the p53-controlled ribonucleotide reductase subunit, have been described in 7 infants from 4 families, who presented with various combinations of hypotonia, tubulopathy, seizures, respiratory distress, diarrhea, and lactic acidosis. All children died before 4 months of age. We sequenced the RRM2B gene in three unrelated cases with unexplained severe mtDNA depletion. The first patient developed intractable diarrhea, profound weakness, respiratory distress, and died at three months. The other two unrelated patients had a much milder phenotype and are still alive at ages 27 and 36 months. All three patients had lactic acidosis and severe depletion of mtDNA in muscle. Muscle histochemistry showed RRF and COX deficiency. Sequencing the RRM2B gene revealed three missense mutations and two single nucleotide deletions in exon 6, 8 and 9, confirming that RRM2B mutations are important causes of MDS and that the clinical phenotype is heterogeneous and not invariably fatal in infancy. PMID:18504129

Mutation of A677 in histone methyltransferase EZH2 in human B-cell lymphoma promotes hypertrimethylation of histone H3 on lysine 27 (H3K27)

PubMed Central

McCabe, Michael T.; Graves, Alan P.; Ganji, Gopinath; Diaz, Elsie; Halsey, Wendy S.; Jiang, Yong; Smitheman, Kimberly N.; Ott, Heidi M.; Pappalardi, Melissa B.; Allen, Kimberly E.; Chen, Stephanie B.; Della Pietra, Anthony; Dul, Edward; Hughes, Ashley M.; Gilbert, Seth A.; Thrall, Sara H.; Tummino, Peter J.; Kruger, Ryan G.; Brandt, Martin; Schwartz, Benjamin; Creasy, Caretha L.

2012-01-01

Trimethylation of histone H3 on lysine 27 (H3K27me3) is a repressive posttranslational modification mediated by the histone methyltransferase EZH2. EZH2 is a component of the polycomb repressive complex 2 and is overexpressed in many cancers. In B-cell lymphomas, its substrate preference is frequently altered through somatic mutation of the EZH2 Y641 residue. Herein, we identify mutation of EZH2 A677 to a glycine (A677G) among lymphoma cell lines and primary tumor specimens. Similar to Y641 mutant cell lines, an A677G mutant cell line revealed aberrantly elevated H3K27me3 and decreased monomethylated H3K27 (H3K27me1) and dimethylated H3K27 (H3K27me2). A677G EZH2 possessed catalytic activity with a substrate specificity that was distinct from those of both WT EZH2 and Y641 mutants. Whereas WT EZH2 displayed a preference for substrates with less methylation [unmethylated H3K27 (H3K27me0):me1:me2 kcat/Km ratio = 9:6:1] and Y641 mutants preferred substrates with greater methylation (H3K27me0:me1:me2 kcat/Km ratio = 1:2:13), the A677G EZH2 demonstrated nearly equal efficiency for all three substrates (H3K27me0:me1:me2 kcat/Km ratio = 1.1:0.6:1). When transiently expressed in cells, A677G EZH2, but not WT EZH2, increased global H3K27me3 and decreased H3K27me2. Structural modeling of WT and mutant EZH2 suggested that the A677G mutation acquires the ability to methylate H3K27me2 through enlargement of the lysine tunnel while preserving activity with H3K27me0/me1 substrates through retention of the Y641 residue that is crucial for orientation of these smaller substrates. This mutation highlights the interplay between Y641 and A677 residues in the substrate specificity of EZH2 and identifies another lymphoma patient population that harbors an activating mutation of EZH2. PMID:22323599

Mutation of A677 in histone methyltransferase EZH2 in human B-cell lymphoma promotes hypertrimethylation of histone H3 on lysine 27 (H3K27).

PubMed

McCabe, Michael T; Graves, Alan P; Ganji, Gopinath; Diaz, Elsie; Halsey, Wendy S; Jiang, Yong; Smitheman, Kimberly N; Ott, Heidi M; Pappalardi, Melissa B; Allen, Kimberly E; Chen, Stephanie B; Della Pietra, Anthony; Dul, Edward; Hughes, Ashley M; Gilbert, Seth A; Thrall, Sara H; Tummino, Peter J; Kruger, Ryan G; Brandt, Martin; Schwartz, Benjamin; Creasy, Caretha L

2012-02-21

Trimethylation of histone H3 on lysine 27 (H3K27me3) is a repressive posttranslational modification mediated by the histone methyltransferase EZH2. EZH2 is a component of the polycomb repressive complex 2 and is overexpressed in many cancers. In B-cell lymphomas, its substrate preference is frequently altered through somatic mutation of the EZH2 Y641 residue. Herein, we identify mutation of EZH2 A677 to a glycine (A677G) among lymphoma cell lines and primary tumor specimens. Similar to Y641 mutant cell lines, an A677G mutant cell line revealed aberrantly elevated H3K27me3 and decreased monomethylated H3K27 (H3K27me1) and dimethylated H3K27 (H3K27me2). A677G EZH2 possessed catalytic activity with a substrate specificity that was distinct from those of both WT EZH2 and Y641 mutants. Whereas WT EZH2 displayed a preference for substrates with less methylation [unmethylated H3K27 (H3K27me0):me1:me2 k(cat)/K(m) ratio = 9:6:1] and Y641 mutants preferred substrates with greater methylation (H3K27me0:me1:me2 k(cat)/K(m) ratio = 1:2:13), the A677G EZH2 demonstrated nearly equal efficiency for all three substrates (H3K27me0:me1:me2 k(cat)/K(m) ratio = 1.1:0.6:1). When transiently expressed in cells, A677G EZH2, but not WT EZH2, increased global H3K27me3 and decreased H3K27me2. Structural modeling of WT and mutant EZH2 suggested that the A677G mutation acquires the ability to methylate H3K27me2 through enlargement of the lysine tunnel while preserving activity with H3K27me0/me1 substrates through retention of the Y641 residue that is crucial for orientation of these smaller substrates. This mutation highlights the interplay between Y641 and A677 residues in the substrate specificity of EZH2 and identifies another lymphoma patient population that harbors an activating mutation of EZH2.

Novel GATAD2B loss-of-function mutations cause intellectual disability in two unrelated cases.

PubMed

Luo, Xiaomei; Zou, Yongyi; Tan, Bo; Zhang, Yue; Guo, Jing; Zeng, Lanlan; Zhang, Rui; Tan, Hu; Wei, Xianda; Hu, Yiqiao; Zheng, Yu; Liang, Desheng; Wu, Lingqian

2017-04-01

GATA zinc finger domain-containing 2B (GATAD2B) is a subunit of the methyl-CpG-binding protein-1 complex (MECP1), which deacetylates methylated nucleosomes and regresses transcriptional activity. Recently, GATAD2B has been elucidated as a candidate gene in patients with intellectual disability (ID). In this study, we identified two novel heterozygous frameshift mutations of GATAD2B in two unrelated ID cases through next-generation sequencing (NGS). Both of the mutations c.80_81insGATGT and c.552_555delGAAA cause truncated proteins that might be detrimental to neurodevelopment. We performed western blotting and observed a reduction in the target protein compared with normal controls. This is the first report of GATAD2B in Chinese ID patients. Our findings will broaden the spectrum of GATAD2B mutations and facilitate genetic diagnosis and counseling.

Late onset bipolar disorder and frontotemporal dementia with mutation in progranulin gene: a case report.

PubMed

Rubino, Elisa; Vacca, Alessandro; Gallone, Salvatore; Govone, Flora; Zucca, Milena; Gai, Annalisa; Ferrero, Patrizia; Fenoglio, Pierpaola; Giordana, Maria Teresa; Rainero, Innocenzo

2017-11-01

Bipolar disorder is a chronic psychiatric illness characterised by fluctuation in mood state, with a relapsing and remitting course. Frontotemporal dementia (FTD) is a clinically and genetically heterogeneous syndrome, with the most frequent phenotype being behavioural variant frontotemporal dementia (bvFTD). Here, we report the case of an Italian male presenting with late-onset bipolar disorder that developed into bvFTD over time, carrying a mutation in the GRN gene. Interestingly, the patient carried the c.1639 C > T variant in the GRN gene, resulting in a R547C substitution. Our case report further corroborates the notion that, in addition to FTD, progranulin may be involved in the neurobiology of bipolar disorder type 1, and suggests to screen patients with late-onset bipolar disorder for GRN mutations.

Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

PubMed

Liu, Harry; Wu, Chengbiao

2017-02-04

Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B) is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M) in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s) enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF) in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A "gain of toxicity" model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s) causes a "loss of function", resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons) of CMT2B are needed to precisely define the disease mechanisms.

Mutation of RNA polymerase beta subunit (rpoB) promotes hVISA-to-VISA phenotypic conversion of strain Mu3.

PubMed

Matsuo, Miki; Hishinuma, Tomomi; Katayama, Yuki; Cui, Longzhu; Kapi, Maria; Hiramatsu, Keiichi

2011-09-01

The clinical vancomycin-intermediate Staphylococcus aureus (VISA) strain Mu50 carries two mutations in the vraSR and graRS two-component regulatory systems (TCRSs), namely, vraS(I5N) and graR(N197S) (hereinafter designated graR). The clinical heterogeneously vancomycin-intermediate S. aureus (hVISA) strain Mu3 shares with Mu50 the mutation in vraS that encodes the VraS two-component histidine kinase. Previously, we showed that introduction of the plasmid pgraR, carrying the mutated two-component response regulator graR, converted the hVISA strain Mu3 into VISA (vancomycin MIC = 4 mg/liter). Subsequently, however, we found that the introduction of a single copy of graR into the Mu3 chromosome by a gene replacement method did not confer on Mu3 the VISA phenotype. The gene-replaced strain Mu3graR thus obtained remained hVISA (MIC ≤ 2 mg/liter), although a small increase in vancomycin MIC was observed compared to that of the parent strain Mu3. Reevaluation of the Mu3 and Mu50 genomes revealed the presence of another mutation responsible for the expression of the VISA phenotype in Mu50. Here, we demonstrate that in addition to the two regulator mutations, a third mutation found in the Mu50 rpoB gene, encoding the RNA polymerase β subunit, was required for Mu3 to achieve the level of vancomycin resistance of Mu50. The selection of strain Mu3graR with rifampin gave rise to rpoB mutants with various levels of increased vancomycin resistance. Furthermore, 3 (33%) of 10 independently isolated VISA strains established from the heterogeneous subpopulations of Mu3graR were found to possess rpoB mutations with or without an accompanying rifampin-resistance phenotype. The data indicate that a sizable proportion of the resistant hVISA cell subpopulations is composed of spontaneous rpoB mutants with various degrees of increased vancomycin resistance.

[A novel homozygous mutation p.E25X in the HSD3B2 gene causing salt wasting 3β-hydroxysteroid dehydrogenases deficiency in a Chinese pubertal girl: a delayed diagnosis until recurrent ovary cysts].

PubMed

Huang, Yonglan; Zheng, Jipeng; Xie, Ting; Xiao, Qing; Lu, Shaomei; Li, Xiuzhen; Cheng, Jing; Chen, Lihe; Liu, Li

2014-12-01

3β- hydroxysteroid dehydrogenase deficiency (3βHSD), a rare form of congenital adrenal hyperplasia (CAH) resulted from mutations in the HSD3B2 gene that impair steroidogenesis in both adrenals and gonads. We report clinical features and the results of HSD3B2 gene analysis of a Chinese pubertal girl with salt wasting 3βHSD deficiency. We retrospectively reviewed clinical presentations and steroid profiles of the patient diagnosed in Guangzhou Women and Children's Medical Center in 2013. PCR and direct sequencing were used to identify any mutation in the HSD3B2 gene. A 13-year-old girl was diagnosed as CAH after birth because of salt-wasting with mild clitorimegaly and then was treated with glucocorticoid replacement. Breast and pubic hair development were normal, and menarche occurred at 12 yr, followed by menstrual bleeding about every 45 days. In the last one year laparoscopic operation and ovariocentesis were performed one after another for recurrent ovary cysts. Under corticoid acetate therapy, ACTH 17.10 pmol/L (normal 0-10.12), testosterone 1.31 nmol/L (normal <0.7), dehydroepiandrosterone sulfate 13.30 µmol/L (normal 0.95 - 11.67), cortisol 720 nmol/L (normal 130-772.8), androstenedione, 17-hydroxyprogesterone and progesterone were normal. Estradiol 461 pmol/L, follicle-stimulating hormone 3.04 IU/L, luteinizing hormone 8.52 IU/L in follicular phase. A pelvic ultrasound showed lateral ovaries cysts (58 mm × 50 mm × 35 mm) and a midcycle-type endometrium. A novel nonsense mutation c.73G >T (p.E25X) was identified in HSD3B2 gene. The girl was homozygous and her mother was heterozygous, while her father was not identified with this mutation. A classic 3βHSD deficiency is characterized by salt wasting and mild virilization in female. Ovary cysts may be the one of features of gonad phenotype indicating ovary 3βHSD deficiency. A novel homozygous mutation c.73G >T(p.E25X) was related to the classical phenotype.

TP53 mutation and survival in aggressive B cell lymphoma.

PubMed

Zenz, Thorsten; Kreuz, Markus; Fuge, Maxi; Klapper, Wolfram; Horn, Heike; Staiger, Annette M; Winter, Doris; Helfrich, Hanne; Huellein, Jennifer; Hansmann, Martin-Leo; Stein, Harald; Feller, Alfred; Möller, Peter; Schmitz, Norbert; Trümper, Lorenz; Loeffler, Markus; Siebert, Reiner; Rosenwald, Andreas; Ott, German; Pfreundschuh, Michael; Stilgenbauer, Stephan

2017-10-01

TP53 is mutated in 20-25% of aggressive B-cell lymphoma (B-NHL). To date, no studies have addressed the impact of TP53 mutations in prospective clinical trial cohorts. To evaluate the impact of TP53 mutation to current risk models in aggressive B-NHL, we investigated TP53 gene mutations within the RICOVER-60 trial. Of 1,222 elderly patients (aged 61-80 years) enrolled in the study and randomized to six or eight cycles of CHOP-14 with or without Rituximab (NCT00052936), 265 patients were analyzed for TP53 mutations. TP53 mutations were demonstrated in 63 of 265 patients (23.8%). TP53 mutation was associated with higher LDH (65% vs. 37%; p < 0.001), higher international prognostic index-Scores (IPI 4/5 27% vs. 12%; p = 0.025) and B-symptoms (41% vs. 24%; p = 0.011). Patients with TP53 mutation were less likely to obtain a complete remission CR/CRu (CR unconfirmed) 61.9% (mut) vs. 79.7% (wt) (p = 0.007). TP53 mutations were associated with decreased event-free (EFS), progression-free (PFS) and overall survival (OS) (median observation time of 40.2 months): the 3 year EFS, PFS and OS were 42% (vs. 60%; p = 0.012), 42% (vs. 67.5%; p < 0.001) and 50% (vs. 76%; p < 0.001) for the TP53 mutation group. In a Cox proportional hazard analysis adjusting for IPI-factors and treatment arms, TP53 mutation was shown to be an independent predictor of EFS (HR 1.5), PFS (HR 2.0) and OS (HR 2.3; p < 0.001). TP53 mutations are independent predictors of survival in untreated patients with aggressive CD20+ lymphoma. TP53 mutations should be considered for risk models in DLBCL and strategies to improve outcome for patients with mutant TP53 must be developed. © 2017 UICC.

Germline mosaicism of PHOX2B mutation accounts for familial recurrence of congenital central hypoventilation syndrome (CCHS).

PubMed

Rand, Casey M; Yu, Min; Jennings, Lawrence J; Panesar, Kelvin; Berry-Kravis, Elizabeth M; Zhou, Lili; Weese-Mayer, Debra E

2012-09-01

Congenital central hypoventilation syndrome (CCHS), a rare disorder characterized by alveolar hypoventilation and autonomic dysregulation, is caused by mutations in the PHOX2B gene. Most mutations occur de novo, but recent evidence suggests that up to 25% are inherited from asymptomatic parents with somatic mosaicism for these mutations. However, to date, germline mosaicism has not been reported. This report describes a family with recurrence of PHOX2B mutation-confirmed CCHS due to germline mosaicism. The first occurrence was a baby girl, noted on day 2 of life to have multiple episodes of apnea, bradycardia, and cyanosis while breathing room air. PHOX2B gene testing confirmed the diagnosis of CCHS with a heterozygous polyalanine repeat expansion mutation (PARM); genotype 20/27 (normal 20/20). Both parents tested negative for this mutation using fragment analysis (limit of detection<1%). Upon subsequent pregnancy [paternity confirmed using short tandem repeat (STR) analysis], amniocentesis testing identified the PHOX2B 20/27 genotype, confirmed with repeat testing. Elective abortion was performed at 21.5 weeks gestation. Testing of abortus tissue confirmed amniocentesis testing. The PHOX2B 20/27 expansion was not observed in a paternal sperm sample. This case represents the first reported family with recurrence of PHOX2B mutation-confirmed CCHS without detection of a parental carrier state or mosaicism, confirming the previously hypothesized possibility of germline mosaicism for PHOX2B mutations. This is an important finding for genetic counseling of CCHS families, suggesting that even if somatic mosaicism is not detected in parental samples, there is still reason for careful genetic counseling and consideration of prenatal testing during subsequent pregnancies. Copyright © 2012 Wiley Periodicals, Inc.

A novel mutation in HSD11B2 causes apparent mineralocorticoid excess in an Omani kindred.

PubMed

Yau, Mabel; Azkawi, Hanan Said Al; Haider, Shozeb; Khattab, Ahmed; Badi, Maryam Al; Abdullah, Wafa; Senani, Aisha Al; Wilson, Robert C; Yuen, Tony; Zaidi, Mone; New, Maria I

2016-07-01

Apparent mineralocorticoid excess (AME) is a rare autosomal recessive genetic disorder causing severe hypertension in childhood due to a deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), which is encoded by HSD11B2. Without treatment, chronic hypertension leads to early development of end-organ damage. Approximately 40 causative mutations in HSD11B2 have been identified in ∼100 AME patients worldwide. We have studied the clinical presentation, biochemical parameters, and molecular genetics in six patients from a consanguineous Omani family with AME. DNA sequence analysis of affected members of this family revealed homozygous c.799A>G mutations within exon 4 of HSD11B2, corresponding to a p.T267A mutation of 11βHSD2. The structural change and predicted consequences owing to the p.T267A mutation have been modeled in silico. We conclude that this novel mutation is responsible for AME in this family. © 2016 New York Academy of Sciences.

Epistatic interactions between mutations of TACI (TNFRSF13B) and TCF3 result in a severe primary immunodeficiency disorder and systemic lupus erythematosus

PubMed Central

Ameratunga, Rohan; Koopmans, Wikke; Woon, See-Tarn; Leung, Euphemia; Lehnert, Klaus; Slade, Charlotte A; Tempany, Jessica C; Enders, Anselm; Steele, Richard; Browett, Peter; Hodgkin, Philip D; Bryant, Vanessa L

2017-01-01

Common variable immunodeficiency disorders (CVID) are a group of primary immunodeficiencies where monogenetic causes account for only a fraction of cases. On this evidence, CVID is potentially polygenic and epistatic although there are, as yet, no examples to support this hypothesis. We have identified a non-consanguineous family, who carry the C104R (c.310T>C) mutation of the Transmembrane Activator Calcium-modulator and cyclophilin ligand Interactor (TACI, TNFRSF13B) gene. Variants in TNFRSF13B/TACI are identified in up to 10% of CVID patients, and are associated with, but not solely causative of CVID. The proband is heterozygous for the TNFRSF13B/TACI C104R mutation and meets the Ameratunga et al. diagnostic criteria for CVID and the American College of Rheumatology criteria for systemic lupus erythematosus (SLE). Her son has type 1 diabetes, arthritis, reduced IgG levels and IgA deficiency, but has not inherited the TNFRSF13B/TACI mutation. Her brother, homozygous for the TNFRSF13B/TACI mutation, is in good health despite profound hypogammaglobulinemia and mild cytopenias. We hypothesised that a second unidentified mutation contributed to the symptomatic phenotype of the proband and her son. Whole-exome sequencing of the family revealed a de novo nonsense mutation (T168fsX191) in the Transcription Factor 3 (TCF3) gene encoding the E2A transcription factors, present only in the proband and her son. We demonstrate mutations of TNFRSF13B/TACI impair immunoglobulin isotype switching and antibody production predominantly via T-cell-independent signalling, while mutations of TCF3 impair both T-cell-dependent and -independent pathways of B-cell activation and differentiation. We conclude that epistatic interactions between mutations of the TNFRSF13B/TACI and TCF3 signalling networks lead to the severe CVID-like disorder and SLE in the proband. PMID:29114388

Disease-associated missense mutations in GluN2B subunit alter NMDA receptor ligand binding and ion channel properties.

PubMed

Fedele, Laura; Newcombe, Joseph; Topf, Maya; Gibb, Alasdair; Harvey, Robert J; Smart, Trevor G

2018-03-06

Genetic and bioinformatic analyses have identified missense mutations in GRIN2B encoding the NMDA receptor GluN2B subunit in autism, intellectual disability, Lennox Gastaut and West Syndromes. Here, we investigated several such mutations using a near-complete, hybrid 3D model of the human NMDAR and studied their consequences with kinetic modelling and electrophysiology. The mutants revealed reductions in glutamate potency; increased receptor desensitisation; and ablation of voltage-dependent Mg 2+ block. In addition, we provide new views on Mg 2+ and NMDA channel blocker binding sites. We demonstrate that these mutants have significant impact on excitatory transmission in developing neurons, revealing profound changes that could underlie their associated neurological disorders. Of note, the NMDAR channel mutant GluN2B V618G unusually allowed Mg 2+ permeation, whereas nearby N615I reduced Ca 2+ permeability. By identifying the binding site for an NMDAR antagonist that is used in the clinic to rescue gain-of-function phenotypes, we show that drug binding may be modified by some GluN2B disease-causing mutations.

EZH2 and CD79B mutational status over time in B-cell non-Hodgkin lymphomas detected by high-throughput sequencing using minimal samples

PubMed Central

Saieg, Mauro Ajaj; Geddie, William R; Boerner, Scott L; Bailey, Denis; Crump, Michael; da Cunha Santos, Gilda

2013-01-01

BACKGROUND: Numerous genomic abnormalities in B-cell non-Hodgkin lymphomas (NHLs) have been revealed by novel high-throughput technologies, including recurrent mutations in EZH2 (enhancer of zeste homolog 2) and CD79B (B cell antigen receptor complex-associated protein beta chain) genes. This study sought to determine the evolution of the mutational status of EZH2 and CD79B over time in different samples from the same patient in a cohort of B-cell NHLs, through use of a customized multiplex mutation assay. METHODS: DNA that was extracted from cytological material stored on FTA cards as well as from additional specimens, including archived frozen and formalin-fixed histological specimens, archived stained smears, and cytospin preparations, were submitted to a multiplex mutation assay specifically designed for the detection of point mutations involving EZH2 and CD79B, using MassARRAY spectrometry followed by Sanger sequencing. RESULTS: All 121 samples from 80 B-cell NHL cases were successfully analyzed. Mutations in EZH2 (Y646) and CD79B (Y196) were detected in 13.2% and 8% of the samples, respectively, almost exclusively in follicular lymphomas and diffuse large B-cell lymphomas. In one-third of the positive cases, a wild type was detected in a different sample from the same patient during follow-up. CONCLUSIONS: Testing multiple minimal tissue samples using a high-throughput multiplex platform exponentially increases tissue availability for molecular analysis and might facilitate future studies of tumor progression and the related molecular events. Mutational status of EZH2 and CD79B may vary in B-cell NHL samples over time and support the concept that individualized therapy should be based on molecular findings at the time of treatment, rather than on results obtained from previous specimens. Cancer (Cancer Cytopathol) 2013;121:377–386. © 2013 American Cancer Society. PMID:23361872

Profiling Speech and Pausing in Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD)

PubMed Central

Yunusova, Yana; Graham, Naida L.; Shellikeri, Sanjana; Phuong, Kent; Kulkarni, Madhura; Rochon, Elizabeth; Tang-Wai, David F.; Chow, Tiffany W.; Black, Sandra E.; Zinman, Lorne H.; Green, Jordan R.

2016-01-01

Objective This study examines reading aloud in patients with amyotrophic lateral sclerosis (ALS) and those with frontotemporal dementia (FTD) in order to determine whether differences in patterns of speaking and pausing exist between patients with primary motor vs. primary cognitive-linguistic deficits, and in contrast to healthy controls. Design 136 participants were included in the study: 33 controls, 85 patients with ALS, and 18 patients with either the behavioural variant of FTD (FTD-BV) or progressive nonfluent aphasia (FTD-PNFA). Participants with ALS were further divided into 4 non-overlapping subgroups—mild, respiratory, bulbar (with oral-motor deficit) and bulbar-respiratory—based on the presence and severity of motor bulbar or respiratory signs. All participants read a passage aloud. Custom-made software was used to perform speech and pause analyses, and this provided measures of speaking and articulatory rates, duration of speech, and number and duration of pauses. These measures were statistically compared in different subgroups of patients. Results The results revealed clear differences between patient groups and healthy controls on the passage reading task. A speech-based motor function measure (i.e., articulatory rate) was able to distinguish patients with bulbar ALS or FTD-PNFA from those with respiratory ALS or FTD-BV. Distinguishing the disordered groups proved challenging based on the pausing measures. Conclusions and Relevance This study demonstrated the use of speech measures in the identification of those with an oral-motor deficit, and showed the usefulness of performing a relatively simple reading test to assess speech versus pause behaviors across the ALS—FTD disease continuum. The findings also suggest that motor speech assessment should be performed as part of the diagnostic workup for patients with FTD. PMID:26789001

[The role of the Committee for Medicinal Products for Human Use (CHMP) in the European centralised procedure].

PubMed

Enzmann, Harald; Schneider, C

2008-07-01

The centralised procedure for marketing authorisation at the European Medicines Agency (EMEA) started more than 10 years ago, offering marketing authorisation for all member states of the European Union in a single procedure. Originally it was a purely optional alternative to the established national procedures; however, its importance has been growing ever since. The introduction of the mandatory scope for several important indications was a crucial step. The increasing importance of the centralised procedure was paralleled by the increasing weight of the EMEA and of the Committee for Human Medicinal Products (CHMP) who is responsible for scientific evaluation in the centralised procedure. This paper describes the basic principles of the centralised procedure including the definitions of the mandatory and optional scope, and how the CHMP works including its responsibility in European referrals that provide a link to national procedures.

31 CFR 203.15 - Tax deposits using FTD coupons.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Tax deposits using FTD coupons. 203.15 Section 203.15 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE PAYMENT OF FEDERAL TAXES AND THE...

Clinical and pathological features of amyotrophic lateral sclerosis caused by mutation in the C9ORF72 gene on chromosome 9p.

PubMed

Stewart, Heather; Rutherford, Nicola J; Briemberg, Hannah; Krieger, Charles; Cashman, Neil; Fabros, Marife; Baker, Matt; Fok, Alice; DeJesus-Hernandez, Mariely; Eisen, Andrew; Rademakers, Rosa; Mackenzie, Ian R A

2012-03-01

Two studies recently identified a GGGGCC hexanucleotide repeat expansion in a non-coding region of the chromosome 9 open-reading frame 72 gene (C9ORF72) as the cause of chromosome 9p-linked amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In a cohort of 231 probands with ALS, we identified the C9ORF72 mutation in 17 familial (27.4%) and six sporadic (3.6%) cases. Patients with the mutation presented with typical motor features of ALS, although subjects with the C9ORF72 mutation had more frequent bulbar onset, compared to those without this mutation. Dementia was significantly more common in ALS patients and families with the C9ORF72 mutation and was usually early-onset FTD. There was striking clinical heterogeneity among the members of individual families with the mutation. The associated neuropathology was a combination of ALS with TDP-ir inclusions and FTLD-TDP. In addition to TDP-43-immunoreactive pathology, a consistent and specific feature of cases with the C9ORF72 mutation was the presence of ubiquitin-positive, TDP-43-negative inclusions in a variety of neuroanatomical regions, such as the cerebellar cortex. These findings support the C9ORF72 mutation as an important newly recognized cause of ALS, provide a more detailed characterization of the associated clinical and pathological features and further demonstrate the clinical and molecular overlap between ALS and FTD.

Combined fulminant frontotemporal dementia and amyotrophic lateral sclerosis associated with an I113T SOD1 mutation.

PubMed

Katz, Jonathan S; Katzberg, Hans D; Woolley, Susan C; Marklund, Stefan L; Andersen, Peter M

2012-10-01

Mutations in the gene for superoxide dismutase type 1 cause amyotrophic lateral sclerosis (ALS), but are not thought to be associated with frontotemporal dementia (FTD). A lack of detailed case reports is one reason, among others, for this skepticism. This case report comments on a patient with familial ALS caused by I113T mutation in the SOD1 gene presenting with progressive cognitive and behavioral decline two years before developing progressive motor degeneration. In conclusion, this case provides evidence that SOD1 mutations can be associated with FTD.

Frontotemporal dementia with Pick-type histology associated with Q336R mutation in the tau gene.

PubMed

Pickering-Brown, S M; Baker, M; Nonaka, T; Ikeda, K; Sharma, S; Mackenzie, J; Simpson, S A; Moore, J W; Snowden, J S; de Silva, R; Revesz, T; Hasegawa, M; Hutton, M; Mann, D M A

2004-06-01

In this report, we describe the clinical and neuropathological features of a case of familial frontotemporal dementia (FTD), with onset at 58 years of age and disease duration of 10 years, associated with a novel mutation, Q336R, in the tau gene (tau). In vitro studies concerning the properties of tau proteins bearing this mutation, with respect to microtubule assembly and tau filament aggregation, are reported. Clinically, the patient showed alterations in memory, language and executive functions and marked behavioural change consistent with FTD, although the extent of memory impairment was more than is characteristic of FTD. At autopsy, there was degeneration of the frontal and temporal lobes associated with the presence of hyperphosphorylated tau proteins in swollen (Pick) cells and intraneuronal inclusions (Pick bodies). By immunohistochemistry, the Pick bodies contained both 3-repeat and 4-repeat tau proteins although, because no fresh tissues were available for analysis, the exact isoform composition of the aggregated tau proteins could not be determined. Neurons within frontal cortex contained neurofibrillary tangle-like structures, comprising both straight and twisted tubules, or Pick bodies in which the filaments were short and randomly orientated. In vitro, and in common with other tau missense mutations, Q336R caused an increase in tau fibrillogenesis. However, in contrast to most other tau missense mutations, Q336R increased, not decreased, the ability of mutant tau to promote microtubule assembly. Nonetheless, this latter functional change may likewise be detrimental to neuronal function by inducing a compensatory phosphorylation that may yield increased intracellular hyperphosphorylated tau species that are also liable to fibrillize. We believe the mutation is indeed pathogenic and disease causing and not simply a coincidental rare and benign polymorphism. Since this mutation is segregating with the FTD clinical and neuropathological phenotype, it has

Identifying bvFTD Within the Wide Spectrum of Late Onset Frontal Lobe Syndrome: A Clinical Approach.

PubMed

Krudop, Welmoed A; Kerssens, Cora J; Dols, Annemiek; Prins, Niels D; Möller, Christiane; Schouws, Sigfried; van der Flier, Wiesje M; Scheltens, Philip; Sikkes, Sietske; Stek, Max L; Pijnenburg, Yolande A L

2015-10-01

The behavioral variant of frontotemporal dementia (bvFTD) can be difficult to diagnose because of the extensive differential diagnosis, including many other diseases presenting with a frontal lobe syndrome. We aimed to identify the diagnostic spectrum causing a late onset frontal lobe syndrome and examine the quality of commonly used instruments to distinguish between bvFTD and non-bvFTD patients, within this syndrome. A total of 137 patients fulfilling the criteria of late onset frontal lobe syndrome, aged 45 to 75 years, were included in a prospective observational study. Diagnoses were made after clinical and neuropsychological examination, and neuroimaging and cerebral spinal fluid results were taken into account. Baseline characteristics and the scores on the Mini-Mental State Exam (MMSE), frontal assessment battery (FAB), Frontal Behavioral Inventory (FBI), and Stereotypy Rating Inventory (SRI) were compared between the bvFTD and the non-bvFTD group. Fifty-five (40%) of the patients received a bvFTD diagnosis (33% probable and 7% possible bvFTD). Fifty-one patients (37%) had a psychiatric disorder, including 20 with major depressive disorder. Thirty-one patients received an alternative neurological, including neurodegenerative, diagnosis. MMSE and FAB scores were unspecific for a particular diagnosis. A score above 12 on the positive FBI subscale or a score above 5 on the SRI were indicative of a bvFTD diagnosis. A broad spectrum of both neurological and psychiatric disorders underlies late onset frontal lobe syndrome, of which bvFTD was the most prevalent diagnosis in our cohort. The commonly used MMSE and the FAB could not successfully distinguish between bvFTD and non-bvFTD, but this could be achieved with the more specific FBI and SRI. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Alteration of the SETBP1 gene and splicing pathway genes SF3B1, U2AF1, and SRSF2 in childhood acute myeloid leukemia.

PubMed

Choi, Hyun-Woo; Kim, Hye-Ran; Baek, Hee-Jo; Kook, Hoon; Cho, Duck; Shin, Jong-Hee; Suh, Soon-Pal; Ryang, Dong-Wook; Shin, Myung-Geun

2015-01-01

Recurrent somatic SET-binding protein 1 (SETBP1) and splicing pathway gene mutations have recently been found in atypical chronic myeloid leukemia and other hematologic malignancies. These mutations have been comprehensively analyzed in adult AML, but not in childhood AML. We investigated possible alteration of the SETBP1, splicing factor 3B subunit 1 (SF3B1), U2 small nuclear RNA auxiliary factor 1 (U2AF1), and serine/arginine-rich splicing factor 2 (SRSF2) genes in childhood AML. Cytogenetic and molecular analyses were performed to reveal chromosomal and genetic alterations. Sequence alterations in the SETBP1, SF3B1, U2AF1, and SRSF2 genes were examined by using direct sequencing in a cohort of 53 childhood AML patients. Childhood AML patients did not harbor any recurrent SETBP1 gene mutations, although our study did identify a synonymous mutation in one patient. None of the previously reported aberrations in the mutational hotspot of SF3B1, U2AF1, and SRSF2 were identified in any of the 53 patients. Alterations of the SETBP1 gene or SF3B1, U2AF1, and SRSF2 genes are not common genetic events in childhood AML, implying that the mutations are unlikely to exert a driver effect in myeloid leukemogenesis during childhood.

Systemic deregulation of autophagy upon loss of ALS- and FTD-linked C9orf72.

PubMed

Ji, Yon Ju; Ugolino, Janet; Brady, Nathan Ryan; Hamacher-Brady, Anne; Wang, Jiou

2017-07-03

A genetic mutation in the C9orf72 gene causes the most common forms of neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The C9orf72 protein, predicted to be a DENN-family protein, is reduced in ALS and FTD, but its functions remain poorly understood. Using a 3110043O21Rik/C9orf72 knockout mouse model, as well as cellular analysis, we have found that loss of C9orf72 causes alterations in the signaling states of central autophagy regulators. In particular, C9orf72 depletion leads to reduced activity of MTOR, a negative regulator of macroautophagy/autophagy, and concomitantly increased TFEB levels and nuclear translocation. Consistent with these alterations, cells exhibit enlarged lysosomal compartments and enhanced autophagic flux. Loss of the C9orf72 interaction partner SMCR8 results in similar phenotypes. Our findings suggest that C9orf72 functions as a potent negative regulator of autophagy, with a central role in coupling the cellular metabolic state with autophagy regulation. We thus propose C9orf72 as a fundamental component of autophagy signaling with implications in basic cell physiology and pathophysiology, including neurodegeneration.

Comparison of Detection Rate and Mutational Pattern of Drug-Resistant Mutations Between a Large Cohort of Genotype B and Genotype C Hepatitis B Virus-Infected Patients in North China.

PubMed

Li, Xiaodong; Liu, Yan; Xin, Shaojie; Ji, Dong; You, Shaoli; Hu, Jinhua; Zhao, Jun; Wu, Jingjing; Liao, Hao; Zhang, Xin-Xin; Xu, Dongping

2017-06-01

The study aimed to investigate the association of prevalent genotypes in China (HBV/C and HBV/B) with HBV drug-resistant mutations. A total of 13,847 nucleos(t)ide analogue (NA)-treated patients with chronic HBV infection from North China were enrolled. HBV genotypes and resistant mutations were determined by direct sequencing and confirmed by clonal sequencing if necessary. HBV/B, HBV/C, and HBV/D occupied 14.3%, 84.9%, and 0.8% across the study population, respectively. NA usage had no significant difference between HBV/B- and HBV/C-infected patients. Lamivudine-resistant mutations were more frequently detected in HBV/C-infected patients, compared with HBV/B-infected patients (31.67% vs. 25.26%, p < 0.01). Adefovir- and entecavir-resistant mutation detection rates were similar, but the mutational pattern was different between the two genotypes. For adefovir-resistant mutations, HBV/C-infected patients had a higher detection rate of rtA181 V (HBV/C 5.29% vs. HBV/B 1.36%, p < 0.01) and a lower detection rate of rtN236T (2.70% vs. 6.54%, p < 0.01). For entecavir-resistant mutations, HBV/C-infected patients had a higher detection rate of rtM204 V/I+T184 substitution or S202G/C (3.66% vs. 2.16%, p < 0.01) and a lower detection rate of rtM204 V/I+M250 V/I/L substitution (0.67% vs. 1.46%, p < 0.01). Multidrug-resistant mutations (defined as coexistence of mutation to nucleoside and nucleotide analogues) were detected in 104 patients. HBV/C-infected patients had a higher detection rate of multidrug-resistant mutation than HBV/B-infected patients (0.83% vs. 0.35%, p < 0.05). The study for the first time clarified that HBV/C-infected patients had a higher risk to develop multidrug-resistant mutations, compared with HBV/B-infected patients; and HBV/C- and HBV/B-infected patients had different inclinations in the ETV-resistant mutational pattern.

The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Myers, Dwight L.

2011-01-01

The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.

MicroRNA-29b Regulates the Expression Level of Human Progranulin, a Secreted Glycoprotein Implicated in Frontotemporal Dementia

PubMed Central

Jiao, Jian; Herl, Lauren D.; Farese, Robert V.; Gao, Fen-Biao

2010-01-01

Progranulin deficiency is thought to cause some forms of frontotemporal dementia (FTD), a major early-onset age-dependent neurodegenerative disease. How progranulin (PGRN) expression is regulated is largely unknown. We identified an evolutionarily conserved binding site for microRNA-29b (miR-29b) in the 3′ untranslated region (3′UTR) of the human PGRN (hPGRN) mRNA. miR-29b downregulates the expression of luciferase through hPGRN or mouse PGRN (mPGRN) 3′UTRs, and the regulation was abolished by mutations in the miR-29b binding site. To examine the direct effect of manipulating endogenous miR-29b on hPGRN expression, we established a stable NIH3T3 cell line that expresses hPGRN under the control of the cytomegalovirus promoter. Ectopic expression of miR-29b decreased hPGRN expression at the both mRNA and protein levels. Conversely, knockdown of endogenous miR-29b with locked nucleic acid increased the production and secretion of hPGRN in NIH3T3 cells. Endogenous hPGRN in HEK 293 cells was also regulated by miR-29b. These findings identify miR-29b as a novel posttranscriptional regulator of PGRN expression, raising the possibility that miR-29b or other miRNAs might be targeted therapeutically to increase hPGRN levels in some FTD patients. PMID:20479936

Cerebrospinal Fluid Progranulin, but Not Serum Progranulin, Is Reduced in GRN-Negative Frontotemporal Dementia.

PubMed

Wilke, Carlo; Gillardon, Frank; Deuschle, Christian; Hobert, Markus A; Jansen, Iris E; Metzger, Florian G; Heutink, Peter; Gasser, Thomas; Maetzler, Walter; Blauwendraat, Cornelis; Synofzik, Matthis

2017-01-01

Reduced progranulin levels are a hallmark of frontotemporal dementia (FTD) caused by loss-of-function (LoF) mutations in the progranulin gene (GRN). However, alterations of central nervous progranulin expression also occur in neurodegenerative disorders unrelated to GRN mutations, such as Alzheimer's disease. We hypothesised that central nervous progranulin levels are also reduced in GRN-negative FTD. Progranulin levels were determined in both cerebrospinal fluid (CSF) and serum in 75 subjects (37 FTD patients and 38 controls). All FTD patients were assessed by whole-exome sequencing for GRN mutations, yielding a target cohort of 34 patients without pathogenic mutations in GRN (GRN-negative cohort) and 3 GRN mutation carriers (2 LoF variants and 1 novel missense variant). Not only the GRN mutation carriers but also the GRN-negative patients showed decreased CSF levels of progranulin (serum levels in GRN-negative patients were normal). The decreased CSF progranulin levels were unrelated to patients' increased CSF levels of total tau, possibly indicating different destructive neuronal processes within FTD neurodegeneration. The patient with the novel GRN missense variant (c.1117C>T, p.P373S) showed substantially decreased CSF levels of progranulin, comparable to the 2 patients with GRN LoF mutations, suggesting a pathogenic effect of this missense variant. Our results indicate that central nervous progranulin reduction is not restricted to the relatively rare cases of FTD caused by GRN LoF mutations, but also contributes to the more common GRN-negative forms of FTD. Central nervous progranulin reduction might reflect a partially distinct pathogenic mechanism underlying FTD neurodegeneration and is not directly linked to tau alterations. © 2016 S. Karger AG, Basel.

Laboratory diagnosis of von Willebrand disease type 1/2E (2A subtype IIE), type 1 Vicenza and mild type 1 caused by mutations in the D3, D4, B1-B3 and C1-C2 domains of the von Willebrand factor gene. Role of von Willebrand factor multimers and the von Willebrand factor propeptide/antigen ratio.

PubMed

Gadisseur, Alain; Berneman, Zwi; Schroyens, Wilfried; Michiels, Jan Jacques

2009-01-01

Autosomal dominant von Willebrand disease (VWD) type 1/2E is a quantitative/qualitative defect in the von Willebrand factor (VWF) caused by heterozygous cysteine and non-cysteine mutations in the D3 domain of the VWF gene and results in a secretion-multimerization-clearance defect in mutant VWF with the loss of large VWF multimers not due to proteolysis. The multimers of patients with dominant VWD type 1/2E due to mutations in the D3 domain show an aberrant triplet structure with lack of outer bands but with pronounced inner bands of the triplet structure combined with a relative decrease in large multimers reflecting heterozygosity for multimerization defects. There is a good response to desmopressin (DDAVP) followed by rapid clearance of VWF:antigen (Ag), factor VIII coagulant activity (FVIII:C) and VWF:ristocetin cofactor activity (RCo) as the main cause of VWD type 1 or 2 with typical 2E multimeric pattern (VWD type 1/2E). Cysteine mutations in the D3 domains (C1130, C1149 and C1190) show pronounced features of VWD 1/2E with the relative loss of large and relative increase in small VWF multimers with abnormal triplet structure in heterozygotes. Such abnormalities are less pronounced in patients with a milder form of VWD type 1 due to non-cysteine mutations W1144G, T1156M and W1120S in the D3 domain. VWD type 1 Vicenza is caused by the R1205H mutation in the D3 domain and characterized by equally low levels of FVIII:C, VWF:Ag and VWF:RCo. The response to DDAVP in VWD Vicenza is good for FVIII:C, VWF:Ag and VWF:RCo, which is followed by a rapid clearance in less than a few hours of FVIII:C and VWF parameters. The ratios for FVIII:C/VWF:Ag, VWF:RCo/Ag and VWF:CB/Ag remain normal before and after DDAVP indicating that VWD Vicenza clearly differs from VWD type 1, 1/2E and 2M. A new set of missense mutations in D4, B1-B3 and C1-C2 domains has been discovered as the cause of a mild VWD type 1 secretion defect with normal VWF multimers or smeary VWF multimeric pattern

Extending Jak2V617F and MplW515 mutation analysis to single hematopoietic colonies and B and T lymphocytes.

PubMed

Pardanani, Animesh; Lasho, Terra L; Finke, Christy; Mesa, Ruben A; Hogan, William J; Ketterling, Rhett P; Gilliland, Dwight Gary; Tefferi, Ayalew

2007-09-01

JAK2V617F and MPLW515L/K are myeloproliferative disorder (MPD)-associated mutations. We genotyped 552 individual hematopoietic colonies obtained by CD34+ cell culture from 16 affected patients (13 JAK2V617F and 3 MPLW515L/K) to determine (a) the proportion of colonies harboring a particular mutation in the presence or absence of cytokines, (b) the lineage distribution of endogenous colonies for each mutation, and (c) the differences (if any) in the pattern of mutation among the various MPDs, as established by genotyping of individual colonies. Genotyping analysis revealed cohabitation of mutation-negative and mutation-positive endogenous colonies in polycythemia vera as well as other MPDs. Culture of progenitor cells harboring MPLW515L/K yielded virtually no endogenous erythroid colonies in contrast to JAK2V617F-harboring progenitor cells. The mutation pattern (i.e., relative distribution of homozygous, heterozygous, or wild-type colonies) was not a distinguishing feature among the MPDs, and MPLW515 mutations were detected in B and/or T lymphocytes in all three patients tested. These observations suggest that clonal myelopoiesis antedates acquisition of JAK2V617F or MPLW515L/K mutations and that the latter is acquired in a lympho-myeloid progenitor cell.

Sh3pxd2b Mice Are a Model for Craniofacial Dysmorphology and Otitis Media

PubMed Central

Yang, Bin; Tian, Cong; Zhang, Zhi-guang; Han, Feng-chan; Azem, Rami; Yu, Heping; Zheng, Ye; Jin, Ge; Arnold, James E.; Zheng, Qing Y.

2011-01-01

Craniofacial defects that occur through gene mutation during development increase vulnerability to eustachian tube dysfunction. These defects can lead to an increased incidence of otitis media. We examined the effects of a mutation in the Sh3pxd2b gene (Sh3pxd2bnee) on the progression of otitis media and hearing impairment at various developmental stages. We found that all mice that had the Sh3pxd2bnee mutation went on to develop craniofacial dysmorphologies and subsequently otitis media, by as early as 11 days of age. We found noteworthy changes in cilia and goblet cells of the middle ear mucosa in Sh3pxd2bnee mutant mice using scanning electronic microscopy. By measuring craniofacial dimensions, we determined for the first time in an animal model that this mouse has altered eustachian tube morphology consistent with a more horizontal position of the eustachian tube. All mutants were found to have hearing impairment. Expression of TNF-α and TLR2, which correlates with inflammation in otitis media, was up-regulated in the ears of mutant mice when examined by immunohistochemistry and semi-quantitative RT-PCR. The mouse model with a mutation in the Sh3pxd2b gene (Sh3pxd2bnee) mirrors craniofacial dysmorphology and otitis media in humans. PMID:21818352

Antisense Proline-Arginine RAN dipeptides linked to C9ORF72-ALS/FTD form toxic nuclear aggregates that initiate in vitro and in vivo neuronal death

PubMed Central

Wen, Xinmei; Tan, Wenzhi; Westergard, Thomas; Krishnamurthy, Karthik; ShamamandriMarkandaiah, Shashirekha; Shi, Yingxiao; Lin, Shaoyu; Shneider, Neil A.; Monaghan, John; Pandey, Udai B.; Pasinelli, Piera; Ichida, Justin K.; Trotti, Davide

2015-01-01

SUMMARY Expanded GGGGCC nucleotide repeats within the C9ORF72 gene are the most common genetic mutation associated with both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Sense and antisense transcripts of these expansions are translated to form five dipeptide repeat proteins (DRPs). We employed primary cortical and motor neuron cultures, live-cell imaging, and transgenic fly models and found that the arginine-rich dipeptides, in particular Proline-Arginine (PR), are potently neurotoxic. Factors that anticipated their neurotoxicity included aggregation in nucleoli, decreased number of processing bodies, and stress granules formation, implying global translational dysregulation as path accountable for toxicity. Nuclear PR aggregates were also found in human-induced motor neurons and postmortem spinal cord tissues from C9ORF72 ALS and ALS/FTD patients. Intronic G4C2 transcripts, but not loss of C9ORF72 protein, are also toxic to motor and cortical neurons. Interestingly, G4C2 transcript-mediated neurotoxicity synergizes with that of PR aggregates, suggesting convergence of mechanisms. PMID:25521377

Do mutations in DNMT3A/3B affect global DNA hypomethylation among benzene-exposed workers in Southeast China?: Effects of mutations in DNMT3A/3B on global DNA hypomethylation.

PubMed

Zhang, Guang-Hui; Lu, Ye; Ji, Bu-Qiang; Ren, Jing-Chao; Sun, Pin; Ding, Shibin; Liao, Xiaoling; Liao, Kaiju; Liu, Jinyi; Cao, Jia; Lan, Qing; Rothman, Nathaniel; Xia, Zhao-Lin

2017-12-01

Global DNA hypomethylation is commonly observed in benzene-exposed workers, but the underlying mechanisms remain unclear. We sought to discover the relationships among reduced white blood cell (WBC) counts, micronuclear (MN) frequency, and global DNA methylation to determine whether there were associations with mutations in DNMT3A/3B. Therefore, we recruited 410 shoe factory workers and 102 controls from Wenzhou in Zhenjiang Province. A Methylated DNA Quantification Kit was used to quantify global DNA methylation, and single nucleotide polymorphisms (SNPs) in DNMT3A (rs36012910, rs1550117, and R882) and DNMT3B (rs1569686, rs2424909, and rs2424913) were identified using the restriction fragment length polymorphism method. A multilinear regression analysis demonstrated that the benzene-exposed workers experienced significant global DNA hypomethylation compared with the controls (β = -0.51, 95% CI: -0.69 to -0.32, P < 0.001). The DNMT3A R882 mutant allele (R882H and R882C) (β = -0.25, 95% CI: -0.54 to 0.04, P = 0.094) and the DNMT3B rs2424909 GG allele (β = -0.37, 95% CI: -0.70 to -0.03, P = 0.031) were significantly associated with global DNA hypomethylation compared with the wild-type genotype after adjusting for confounding factors. Furthermore, the MN frequency in the R882 mutant allele (R882H and R882C) (FR = 1.18, 95% CI: 0.99 to 1.40, P = 0.054) was higher than that of the wild-type. The results imply that hypomethylation occurs due to benzene exposure and that mutations in DNMTs are significantly associated with global DNA methylation, which might have influenced the induction of MN following exposure to benzene. Environ. Mol. Mutagen. 58:678-687, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Translation, cross-cultural adaptation and applicability of the Brazilian version of the Frontotemporal Dementia Rating Scale (FTD-FRS)

PubMed Central

Lima-Silva, Thais Bento; Bahia, Valéria Santoro; Carvalho, Viviane Amaral; Guimarães, Henrique Cerqueira; Caramelli, Paulo; Balthazar, Márcio; Damasceno, Benito; Bottino, Cássio Machado de Campos; Brucki, Sônia Maria Dozzi; Mioshi, Eneida; Nitrini, Ricardo; Yassuda, Mônica Sanches

2013-01-01

BACKGROUND Staging scales for dementia have been devised for grading Alzheimer's disease (AD) but do not include the specific symptoms of frontotemporal lobar degeneration (FTLD). OBJECTIVE To translate and adapt the Frontotemporal Dementia Rating Scale (FTD-FRS) to Brazilian Portuguese. METHODS The cross-cultural adaptation process consisted of the following steps: translation, back-translation (prepared by independent translators), discussion with specialists, and development of a final version after minor adjustments. A pilot application was carried out with 12 patients diagnosed with bvFTD and 11 with AD, matched for disease severity (CDR=1.0). The evaluation protocol included: Addenbrooke's Cognitive Examination-Revised (ACE-R), Mini-Mental State Examination (MMSE), Executive Interview (EXIT-25), Neuropsychiatric Inventory (NPI), Frontotemporal Dementia Rating Scale (FTD-FRS) and Clinical Dementia Rating scale (CDR). RESULTS The Brazilian version of the FTD-FRS seemed appropriate for use in this country. Preliminary results revealed greater levels of disability in bvFTD than in AD patients (bvFTD: 25% mild, 50% moderate and 25% severe; AD: 36.36% mild, 63.64% moderate). It appears that the CDR underrates disease severity in bvFTD since a relevant proportion of patients rated as having mild dementia (CDR=1.0) in fact had moderate or severe levels of disability according to the FTD-FRS. CONCLUSION The Brazilian version of the FTD-FRS seems suitable to aid staging and determining disease progression. PMID:29213863

Transactivation of the Brassica napus napin promoter by ABI3 requires interaction of the conserved B2 and B3 domains of ABI3 with different cis-elements: B2 mediates activation through an ABRE, whereas B3 interacts with an RY/G-box.

PubMed

Ezcurra, I; Wycliffe, P; Nehlin, L; Ellerström, M; Rask, L

2000-10-01

The transcriptional activator ABI3 is a key regulator of gene expression during embryo maturation in crucifers. In monocots, the related VP1 protein regulates the Em promoter synergistically with abscisic acid (ABA). We identified cis-elements in the Brassica napus napin napA promoter mediating regulation by ABI3 and ABA, by analyzing substitution mutation constructs of napA in transgenic tobacco plantlets ectopically expressing ABI3. In transient analysis using particle bombardment of tobacco leaf sections, a tetramer of the distB ABRE (abscisic acid-responsive element) mediated transactivation by ABI3 and ABI3-dependent response to ABA, whereas a tetramer of the composite RY/G complex, containing RY repeats and a G-box, mediated only ABA-independent transactivation by ABI3. Deletion of the conserved B2 and B3 domains of ABI3 abolished transactivation of napA by ABI3. The two domains of ABI3 interact with different cis-elements: B2 is necessary for ABA-independent and ABA-dependent activations through the distB ABRE, whereas B3 interacts with the RY/G complex. Thus B2 mediates the interaction of ABI3 with the protein complex at the ABRE. The regulation of napA by ABI3 differs from Em regulation by VP1, in that the B3 domain of ABI3 is essential for the ABA-dependent regulation of napA.

B3GALNT2-Related Dystroglycanopathy: Expansion of the Phenotype with Novel Mutation Associated with Muscle-Eye-Brain Disease, Walker-Warburg Syndrome, Epileptic Encephalopathy-West Syndrome, and Sensorineural Hearing Loss.

PubMed

Al Dhaibani, Muna A; El-Hattab, Ayman W; Ismayl, Omar; Suleiman, Jehan

2018-05-23

Mutations in B3GALNT2 , encoding a glycosyltransferase enzyme involved in α-dystroglycan glycosylation, have been recently associated with dystroglycanopathy, a well-recognized subtype of congenital muscular dystrophy (CMD). Only a few cases have been reported with B3GALNT2 -related dystroglycanopathy with variable severity ranging from mild CMD to severe muscle-eye-brain disease. Here, we describe a child with a novel homozygous nonsense mutation in B3GALNT2 . The affected child has severe neurological disease since birth, including muscle disease manifested as hypotonia, muscle weakness, and wasting with elevated creatine kinase, eye disease including microphthalmia and blindness, brain disease with extensive brain malformations including massive hydrocephalus, diffuse cobblestone-lissencephaly, deformed craniocervical junction, and pontocerebellar hypoplasia. The clinical and radiologic findings are compatible with a diagnosis of severe muscle-eye-brain disease and more specifically Walker-Warburg syndrome. A more distinct aspect of the clinical phenotype in this child is the presence of refractory epilepsy in the form of epileptic spasms, epileptic encephalopathy, and West syndrome, as well as sensorineural hearing loss. These findings could expand the phenotype of B3GALNT2 -related dystroglycanopathy. In this report, we also provide a detailed review of previously reported cases with B3GALNT2 -related dystroglycanopathy and compare them to our reported child. In addition, we study the genotype-phenotype correlation in these cases. Georg Thieme Verlag KG Stuttgart · New York.

rpoB gene mutations among Mycobacterium tuberculosis isolates from extrapulmonary sites.

PubMed

Khosravi, Azar Dokht; Meghdadi, Hossein; Ghadiri, Ata A; Alami, Ameneh; Sina, Amir Hossein; Mirsaeidi, Mehdi

2018-03-01

The aim of this study was to analyze mutations occurring in the rpoB gene of Mycobacterium tuberculosis (MTB) isolates from clinical samples of extrapulmonary tuberculosis (EPTB). Seventy formalin-fixed, paraffin-embedded samples and fresh tissue samples from confirmed EPTB cases were analyzed. Nested PCR based on the rpoB gene was performed on the extracted DNAs, combined with cloning and subsequent sequencing. Sixty-seven (95.7%) samples were positive for nester PCR. Sequence analysis of the 81 bp region of the rpoB gene demonstrated mutations in 41 (61.2%) of 67 sequenced samples. Several point mutations including deletion mutations at codons 510, 512, 513 and 515, with 45% and 51% of the mutations in codons 512 and 513 respectively were seen, along with 26% replacement mutations at codons 509, 513, 514, 518, 520, 524 and 531. The most common alteration was Gln → His, at codon 513, presented in 30 (75.6%) isolates. This study demonstrated sequence alterations in codon 513 of the 81 bp region of the rpoB gene as the most common mutation occurred in 75.6% of molecularly confirmed rifampin-resistant strains. In addition, simultaneous mutation at codons 512 and 513 was demonstrated in 34.3% of the isolates. © 2018 APMIS. Published by John Wiley & Sons Ltd.

Novel mutations in RAG1/2 and ADA genes in Israeli patients presenting with T-B-SCID or Omenn syndrome.

PubMed

Dalal, Ilan; Tasher, Diana; Somech, Raz; Etzioni, Amos; Garti, Ben-Zion; Lev, Dorit; Cohen, Sarit; Somekh, Eli; Leshinsky-Silver, Esther

2011-09-01

The relative frequency of the different forms of SCID may vary in different countries. The most frequent form in Israel is the autosomal-recessive T-B- SCID or Omenn syndrome while X-linked SCID is rare. We report our immunological and genetic analyses in multicentre study of patients presenting with either T-B- SCID or Omenn syndrome. Among 16 patients, we identified 7 novel mutations in 6 patients. In the RAG1 gene we detected two novel mutations: L454Q and 469 fs-4bpdel. In the RAG 2 gene: 3 novel mutations: D65Y, G157V, and E480X. One T-B- SCID patient was found to be a compound heterozygote for new mutations in the ADA gene: W264X and R235W. Prenatal diagnosis was performed in 8 families while others refused due to religious reasons. Identification of the new mutations expands our knowledge regarding the unique features of SCID phenotype in Israel and may help the families seeking for genetic counseling. Copyright © 2011 Elsevier Inc. All rights reserved.

Rules of co-occurring mutations characterize the antigenic evolution of human influenza A/H3N2, A/H1N1 and B viruses.

PubMed

Chen, Haifen; Zhou, Xinrui; Zheng, Jie; Kwoh, Chee-Keong

2016-12-05

The human influenza viruses undergo rapid evolution (especially in hemagglutinin (HA), a glycoprotein on the surface of the virus), which enables the virus population to constantly evade the human immune system. Therefore, the vaccine has to be updated every year to stay effective. There is a need to characterize the evolution of influenza viruses for better selection of vaccine candidates and the prediction of pandemic strains. Studies have shown that the influenza hemagglutinin evolution is driven by the simultaneous mutations at antigenic sites. Here, we analyze simultaneous or co-occurring mutations in the HA protein of human influenza A/H3N2, A/H1N1 and B viruses to predict potential mutations, characterizing the antigenic evolution. We obtain the rules of mutation co-occurrence using association rule mining after extracting HA1 sequences and detect co-mutation sites under strong selective pressure. Then we predict the potential drifts with specific mutations of the viruses based on the rules and compare the results with the "observed" mutations in different years. The sites under frequent mutations are in antigenic regions (epitopes) or receptor binding sites. Our study demonstrates the co-occurring site mutations obtained by rule mining can capture the evolution of influenza viruses, and confirms that cooperative interactions among sites of HA1 protein drive the influenza antigenic evolution.

Vanishing white matter disease with a novel EIF2B5 mutation: A 10-year follow-up.

PubMed

Bektaş, Gonca; Yeşil, Gözde; Özkan, Melis Ulak; Yıldız, Edibe Pembegül; Uzunhan, Tuğçe Aksu; Çalışkan, Mine

2018-06-19

Vanishing white matter disease is a heterogeneous disorder caused by mutation in one of the five genes encoding subunits of the eukaryotic initiation factor eIF2B. It is a heterogeneous disorder due to phenotypic variation and a clear genotype-phenotype correlation could not be established so far. We describe a novel mutation in the EIF2B5 gene by analyzing the clinical phenotype and the progression of brain lesions for 10 years. A novel mutation in the EIF2B5 gene was detected in the heterozygous state; c.1688G > A (p. Arg563Gln) mutation in exon 12, accompanied by a previously detected c.806G > A (p. Arg269Gln) mutation in exon 6, leading to substitution of arginine for a glutamine. This compound heterozygous mutation was associated with disease onset at early childhood and relatively slow progression of neurological deterioration. In contrast to previous findings indicated the association of c.806G > A mutation and peripheral neuropathy in patients with vanishing white matter disease, electromyography of our case was normal. The corpus callosum inner rim was the affected area at early stages, which may be remarkable for early diagnosis of vanishing white matter disease. Serial follow-up magnetic resonance imaging revealed the white matter signal abnormality, subsequently cystic degeneration and decrease in white matter volume. The novel mutation c.1688G > A in compound heterozygous state leads to intermediate phenotype of the vanishing white matter disease. In the early stages of the disease the signal abnormality in the corpus callosum inner rim might be remarkable. Copyright © 2018 Elsevier B.V. All rights reserved.

The importance of folate, vitamins B6 and B12 for the lowering of homocysteine concentrations for patients with recurrent pregnancy loss and MTHFR mutations.

PubMed

Serapinas, Danielius; Boreikaite, Evelina; Bartkeviciute, Agne; Bandzeviciene, Rita; Silkunas, Mindaugas; Bartkeviciene, Daiva

2017-09-01

In patients with MTHFR (methylenetetrahydrofolate reductase) mutations and hyperhomocysteinemia, recurrent pregnancy loss is a frequent feature. The aim of the study was to evaluate the impact of folic acid, vitamins B6 and B12 supplementation for the lowering of total homocysteine concentrations and pregnancy. 16 patients who had had 3 or more miscarriages and MTHFR mutations were used in the study. They received methylfolate (5mg/day), vitamin B6 (50mg/day) and vitamin B12 (1mg/week). Supplementation induced a decrease in homocysteine from 19.4±5.3μmol/L to 6.9±2.2μmol/L after folate supplementation (p<0.05). During one year 7 women became pregnant and delivered. Two women delivered from the homozygous C677T mutations group (7 patients) and combined heterozygous C677T/A1298C mutations group (5 patients), while 3 deliveries were in A1298C homozygous mutations group (4 patients). In conclusion, supraphysiologic methylfolate, vitamins B6 and B12 supplementation in woman with MTHFR mutations has a beneficial effect on pregnancy outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

Disorders with similar clinical phenotypes reveal underlying genetic interaction: SATB2 acts as an activator of the UPF3B gene

PubMed Central

Leoyklang, Petcharat; Suphapeetiporn, Kanya; Srichomthong, Chalurmpon; Tongkobpetch, Siraprapa; Fietze, Stefanie; Dorward, Heidi; Cullinane, Andrew R.; Gahl, William A.; Huizing, Marjan; Shotelersuk, Vorasuk

2014-01-01

Two syndromic cognitive impairment disorders have very similar craniofacial dysmorphisms. One is caused by mutations of SATB2, a transcription regulator, and the other by heterozygous mutations leading to premature stop codons in UPF3B, encoding a member of the nonsense-mediated mRNA decay complex. Here we demonstrate that the products of these two causative genes function in the same pathway. We show that the SATB2 nonsense mutation in our patient leads to a truncated protein that localizes to the nucleus, forms a dimer with wild-type SATB2 and interferes with its normal activity. This suggests that the SATB2 nonsense mutation has a dominant negative effect. The patient’s leukocytes had significantly decreased UPF3B mRNA compared to controls. This effect was replicated both in vitro, where siRNA knockdown of SATB2 in HEK293 cells resulted in decreased UPF3B expression, and in vivo, where embryonic tissue of Satb2 knock-out mice showed significantly decreased Upf3b expression. Furthermore, chromatin immunoprecipitation demonstrates that SATB2 binds to the UPF3B promoter, and a luciferase reporter assay confirmed that SATB2 expression significantly activates gene transcription using the UPF3B promoter. These findings indicate that SATB2 acts as an activator UPF3B expression through binding to its promoter. This study emphasizes the value of recognizing disorders with similar clinical phenotypes to explore underlying mechanisms of genetic interaction. PMID:23925499

Mutational Analysis of the Stability of the H2A and H2B Histone Monomers

PubMed Central

Stump, Matthew R.; Gloss, Lisa M.

2008-01-01

The eukaryotic histone heterodimer H2A-H2B folds through an obligatory dimeric intermediate that forms in a nearly diffusion-limited association reaction in the stopped-flow dead time. It is unclear whether there is partial folding of the isolated monomers before association. To address the possible contributions of structure in the monomers to the rapid association, we characterized H2A and H2B monomers in the absence of their heterodimeric partner. By far-UV circular dichroism, the H2A and H2B monomers are 15% and 31% helical, respectively—significantly less than observed in X-ray crystal structures. Acrylamide quenching of the intrinsic Tyr fluorescence was indicative of tertiary structure. The H2A and H2B monomers exhibit free energies of unfolding of 2.5 and 2.9 kcal mol−1, respectively; at 10 μM, the sum of the stability of the monomers is ~60% of the stability of the native dimer. The helical content, stability and m values indicate that H2B has a more stable, compact structure than H2A. The monomer m values are larger than expected for the extended histone fold motif, suggesting that the monomers adopt an overly-collapsed structure. Stopped-flow refolding—initiated from urea-denatured monomers or the partially folded monomers populated at low denaturant concentrations—yielded essentially identical rates, indicating that monomer folding is productive in the rapid association and folding of the heterodimer. A series of Ala and Gly mutations were introduced into H2A and H2B to probe the importance of helix propensity on the structure and stability of the monomers. The mutational studies show that the central α-helix of the histone fold, which makes extensive inter-monomer contacts, is structured in H2B but only partially folded in H2A. PMID:18976667

Distribution of HLA-B27 and CYP2D6*4 mutations in the middle Black Sea area (Tokat) of Turkey.

PubMed

Sahin, S; Aydogan, L; Benli, I; Ozyurt, H

2011-12-02

We analyzed distribution of HLA-B27 and CYP2D6*4 mutations in 249 patients from Tokat province in Turkey with symptoms of arthritis, sacroiliac, joint and back pain, using a LightCycler 480 II Real-Time PCR thermal cycler. The Genes-4U was applied for studying HLA-B27 mutation, and the Tib-Molbiol commercial kit was used to examine the CYP2D6*4 mutation. Among the 249 patients, 18.5% had the HLA-B27 mutation. The CYP2D6*4 mutation was found in 22.0% (six homozygotes). Ten patients had both mutations. These frequencies are similar to what has been reported from other populations.

The evolution of cellular deficiency in GATA2 mutation

PubMed Central

Dickinson, Rachel E.; Milne, Paul; Jardine, Laura; Zandi, Sasan; Swierczek, Sabina I.; McGovern, Naomi; Cookson, Sharon; Ferozepurwalla, Zaveyna; Langridge, Alexander; Pagan, Sarah; Gennery, Andrew; Heiskanen-Kosma, Tarja; Hämäläinen, Sari; Seppänen, Mikko; Helbert, Matthew; Tholouli, Eleni; Gambineri, Eleonora; Reykdal, Sigrún; Gottfreðsson, Magnús; Thaventhiran, James E.; Morris, Emma; Hirschfield, Gideon; Richter, Alex G.; Jolles, Stephen; Bacon, Chris M.; Hambleton, Sophie; Haniffa, Muzlifah; Bryceson, Yenan; Allen, Carl; Prchal, Josef T.; Dick, John E.; Bigley, Venetia

2014-01-01

Constitutive heterozygous GATA2 mutation is associated with deafness, lymphedema, mononuclear cytopenias, infection, myelodysplasia (MDS), and acute myeloid leukemia. In this study, we describe a cross-sectional analysis of 24 patients and 6 relatives with 14 different frameshift or substitution mutations of GATA2. A pattern of dendritic cell, monocyte, B, and natural killer (NK) lymphoid deficiency (DCML deficiency) with elevated Fms-like tyrosine kinase 3 ligand (Flt3L) was observed in all 20 patients phenotyped, including patients with Emberger syndrome, monocytopenia with Mycobacterium avium complex (MonoMAC), and MDS. Four unaffected relatives had a normal phenotype indicating that cellular deficiency may evolve over time or is incompletely penetrant, while 2 developed subclinical cytopenias or elevated Flt3L. Patients with GATA2 mutation maintained higher hemoglobin, neutrophils, and platelets and were younger than controls with acquired MDS and wild-type GATA2. Frameshift mutations were associated with earlier age of clinical presentation than substitution mutations. Elevated Flt3L, loss of bone marrow progenitors, and clonal myelopoiesis were early signs of disease evolution. Clinical progression was associated with increasingly elevated Flt3L, depletion of transitional B cells, CD56bright NK cells, naïve T cells, and accumulation of terminally differentiated NK and CD8+ memory T cells. These studies provide a framework for clinical and laboratory monitoring of patients with GATA2 mutation and may inform therapeutic decision-making. PMID:24345756

The cognitive profile of behavioural variant FTD and its similarities with ALS: a systematic review and meta-analysis.

PubMed

Beeldman, Emma; Raaphorst, Joost; Klein Twennaar, Michelle; Govaarts, Rosanne; Pijnenburg, Yolande A L; de Haan, Rob J; de Visser, Marianne; Schmand, Ben A

2018-02-09

Approximately 30% of patients with amyotrophic lateral sclerosis (ALS) have cognitive impairment and 8%-14% fulfil the criteria for behavioural variant frontotemporal dementia (bv-FTD). The cognitive profiles of ALS and bv-FTD have been reported to be comparable, but this has never been systematically investigated. We aimed to determine the cognitive profile of bv-FTD and examine its similarities with that of ALS, to provide evidence for the existence of a cognitive disease continuum encompassing bv-FTD and ALS. We therefore systematically reviewed neuropsychological studies on bv-FTD patients and healthy volunteers. Neuropsychological tests were divided in 10 cognitive domains and effect sizes were calculated for all domains and compared with the cognitive profile of ALS by means of a visual comparison and a Pearson's r correlation coefficient. We included 120 studies, totalling 2425 bv-FTD patients and 2798 healthy controls. All cognitive domains showed substantial effect sizes, indicating cognitive impairment in bv-FTD patients compared to healthy controls. The cognitive domains with the largest effect sizes were social cognition, verbal memory and fluency (1.77-1.53). The cognitive profiles of bv-FTD and ALS (10 cognitive domains, 1287 patients) showed similarities on visual comparison and a moderate correlation 0.58 (p=0.13). When social cognition, verbal memory, fluency, executive functions, language and visuoperception were considered, i.e. the cognitive profile of ALS, Pearson's r was 0.73 (p=0.09), which raised to 0.92 (p=0.03), when language was excluded in this systematic analysis of patients with a non-language subtype of FTD. The cognitive profile of bv-FTD consists of deficits in social cognition, verbal memory, fluency and executive functions and shows similarities with the cognitive profile of ALS. These findings support a cognitive continuum encompassing ALS and bv-FTD. © Article author(s) (or their employer(s) unless otherwise stated in the text

Hexanucleotide Repeats in ALS/FTD Form Length-Dependent RNA Foci, Sequester RNA Binding Proteins, and Are Neurotoxic

PubMed Central

Lee, Youn-Bok; Chen, Han-Jou; Peres, João N.; Gomez-Deza, Jorge; Attig, Jan; Štalekar, Maja; Troakes, Claire; Nishimura, Agnes L.; Scotter, Emma L.; Vance, Caroline; Adachi, Yoshitsugu; Sardone, Valentina; Miller, Jack W.; Smith, Bradley N.; Gallo, Jean-Marc; Ule, Jernej; Hirth, Frank; Rogelj, Boris; Houart, Corinne; Shaw, Christopher E.

2013-01-01

Summary The GGGGCC (G4C2) intronic repeat expansion within C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Intranuclear neuronal RNA foci have been observed in ALS and FTD tissues, suggesting that G4C2 RNA may be toxic. Here, we demonstrate that the expression of 38× and 72× G4C2 repeats form intranuclear RNA foci that initiate apoptotic cell death in neuronal cell lines and zebrafish embryos. The foci colocalize with a subset of RNA binding proteins, including SF2, SC35, and hnRNP-H in transfected cells. Only hnRNP-H binds directly to G4C2 repeats following RNA immunoprecipitation, and only hnRNP-H colocalizes with 70% of G4C2 RNA foci detected in C9ORF72 mutant ALS and FTD brain tissues. We show that expanded G4C2 repeats are potently neurotoxic and bind hnRNP-H and other RNA binding proteins. We propose that RNA toxicity and protein sequestration may disrupt RNA processing and contribute to neurodegeneration. PMID:24290757

Gaucher disease types 1, 2, and 3: differential mutations of the acid beta-glucosidase active site identified with conduritol B epoxide derivatives and sphingosine.

PubMed Central

Grabowski, G A; Dinur, T; Osiecki, K M; Kruse, J R; Legler, G; Gatt, S

1985-01-01

To elucidate the genetic heterogeneity in Gaucher disease, the residual beta-glucosidase in cultured fibroblasts from affected patients with each of the major phenotypes was investigated in vitro and/or in viable cells by inhibitor studies using the covalent catalytic site inhibitors, conduritol B epoxide or its bromo derivative, and the reversible cationic inhibitor, sphingosine. These studies delineated three distinct groups (designated A, B, and C) of residual activities with characteristic responses to these inhibitors. Group A residual enzymes had normal I50 values (i.e., the concentration of inhibitor that results in 50% inhibition) for the inhibitors and normal or nearly normal t1/2 values for conduritol B epoxide. All neuronopathic (types 2 and 3) and most non-Jewish nonneuronopathic (type 1) patients had group A residual activities and, thus, could not be distinguished by these inhibitor studies. Group B residual enzymes had about four- to fivefold increased I50 values for the inhibitors and similarly increased t1/2 values for conduritol B epoxide. All Ashkenazi Jewish type 1 and only two non-Jewish type 1 patients had group B residual activities. The differences in I50 values between groups A and B also were confirmed by determining the uninhibited enzyme activity after culturing the cells in the presence of bromo-conduritol B epoxide. Group C residual activity had intermediate I50 values for the inhibitors and represented a single Afrikaner type 1 patient: this patient was a genetic compound for the group A (type 2) and group B (type 1) mutations. These inhibition studies indicated that: Gaucher disease type 1 is biochemically heterogeneous, neuronopathic and non-Jewish nonneuronopathic phenotypes cannot be reliably distinguished by these inhibitor studies, and the Ashkenazi Jewish form of Gaucher disease type 1 results from a unique mutation in a specific active site domain of acid beta-glucosidase that leads to a defective enzyme with a decreased Vmax

Description of the L76V resistance protease mutation in HIV-1 B and "non-B" subtypes.

PubMed

Charpentier, Charlotte; Lambert-Niclot, Sidonie; Alteri, Claudia; Storto, Alexandre; Flandre, Philippe; Svicher, Valentina; Perno, Carlo-Federico; Brun-Vézinet, Françoise; Calvez, Vincent; Marcelin, Anne-Geneviève; Ceccherini-Silberstein, Francesca; Descamps, Diane

2013-01-01

To describe the prevalence of the L76V protease inhibitors resistance-associated mutation (PI-RAM) in relation with patients' characteristics and protease genotypic background in HIV-1 B- and "non-B"-infected patients. Frequency of the L76V mutation between 1998 and 2010 was surveyed in the laboratory database of 3 clinical centers. Major PI-RAMs were identified according to the IAS-USA list. Fisher's and Wilcoxon tests were used to compare variables. Among the overall 29,643 sequences analyzed, the prevalence of L76V was 1.50%, while was 5.42% in PI-resistant viruses. Since 2008 the prevalence of L76V was higher in "non-B"-infected than in B-infected patients each year. Median time since diagnosis of HIV-1 infection and median time under antiretroviral-based regimen were both shorter in "non-B"- than in B-infected patients (8 vs 11 years, P<0.0001; and 7 vs 8 years, P = 0.004). In addition, "non-B"-infected patients had been pre-exposed to a lower number of PI (2 vs 3, P = 0.016). The L76V was also associated with a lower number of major PI-RAMs in "non-B" vs B samples (3 vs 4, P = 0.0001), and thus it was more frequent found as single major PI-RAM in "non-B" vs B subtype (10% vs 2%, P = 0.014). We showed an impact of viral subtype on the selection of the L76V major PI-RAM with a higher prevalence in "non-B" subtypes observed since 2008. In addition, in "non-B"-infected patients this mutation appeared more rapidly and was associated with less PI-RAM.

Gonococcal Resistance to β-Lactams and Tetracycline Involves Mutation in Loop 3 of the Porin Encoded at the penB Locus

PubMed Central

Gill, M. J.; Simjee, S.; Al-Hattawi, K.; Robertson, B. D.; Easmon, C. S. F.; Ison, C. A.

1998-01-01

penB is a chromosomal mutation that confers resistance to β-lactams and tetracyclines and reduced susceptibility to quinolones in Neisseria gonorrhoeae. It is linked to the porin gene (por) and requires the increased expression of an efflux pump due to mtr. Transformation of a susceptible gonococcus (strain H1) with chromosomal DNA from strain FA140 (penA mtr penB; porin serovar IB1) and conjugal transfer of a β-lactamase-expressing plasmid was used to produce isogenic strains for determination of equilibrium periplasmic penicillin concentrations by the method of Zimmermann and Rosselet (W. Zimmermann and A. Rosselet, Antimicrob. Agents Chemother. 12:368–372, 1977). In transformants with the Mtr and PenB phenotypes, equilibrium concentrations of penicillin were reduced. DNA sequence analysis of por from isogenic penB and penB+ transformants revealed 14 sequence differences; nine of these differences resulted in amino acid changes. Three amino acid changes were found in the putative gonococcal equivalent of the pore-constricting loop 3 of Escherichia coli OmpF. Two of these changes (Gly-101–Ala-102→Asp-Asp) result in an increased negative charge at this position in por loop 3. PCR products comprising the complete por gene from strain FA140 were transformed into strain H1-2 (penA mtr; porin serovar IB-3), with the resulting transformants having the antibiotic susceptibility phenotype associated with penB. penB-like mutations were found in loop 3 of clinical isolates of gonococci with chromosomally mediated resistance to penicillin. We conclude that penB is a mutation in loop 3 of por that reduces porin permeability to hydrophilic antibiotics and plays an important role in the development of chromosomally mediated resistance to penicillin and tetracycline in gonococci. PMID:9797206

Mutations in COQ8B (ADCK4) found in patients with steroid-resistant nephrotic syndrome alter COQ8B function.

PubMed

Vazquez Fonseca, Luis; Doimo, Mara; Calderan, Cristina; Desbats, Maria Andrea; Acosta, Manuel J; Cerqua, Cristina; Cassina, Matteo; Ashraf, Shazia; Hildebrandt, Friedhelm; Sartori, Geppo; Navas, Placido; Trevisson, Eva; Salviati, Leonardo

2018-03-01

Mutations in COQ8B cause steroid-resistant nephrotic syndrome with variable neurological involvement. In yeast, COQ8 encodes a protein required for coenzyme Q (CoQ) biosynthesis, whose precise role is not clear. Humans harbor two paralog genes: COQ8A and COQ8B (previously termed ADCK3 and ADCK4). We have found that COQ8B is a mitochondrial matrix protein peripherally associated with the inner membrane. COQ8B can complement a ΔCOQ8 yeast strain when its mitochondrial targeting sequence (MTS) is replaced by a yeast MTS. This model was employed to validate COQ8B mutations, and to establish genotype-phenotype correlations. All mutations affected respiratory growth, but there was no correlation between mutation type and the severity of the phenotype. In fact, contrary to the case of COQ2, where residual CoQ biosynthesis correlates with clinical severity, patients harboring hypomorphic COQ8B alleles did not display a different phenotype compared with those with null mutations. These data also suggest that the system is redundant, and that other proteins (probably COQ8A) may partially compensate for the absence of COQ8B. Finally, a COQ8B polymorphism, present in 50% of the European population (NM_024876.3:c.521A > G, p.His174Arg), affects stability of the protein and could represent a risk factor for secondary CoQ deficiencies or for other complex traits. © 2017 The Authors. Human Mutation published by Wiley Periodicals, Inc.

Whole-exome sequencing identifies recurrent SF3B1 R625 mutation and comutation of NF1 and KIT in mucosal melanoma.

PubMed

Hintzsche, Jennifer D; Gorden, Nicholas T; Amato, Carol M; Kim, Jihye; Wuensch, Kelsey E; Robinson, Steven E; Applegate, Allison J; Couts, Kasey L; Medina, Theresa M; Wells, Keith R; Wisell, Joshua A; McCarter, Martin D; Box, Neil F; Shellman, Yiqun G; Gonzalez, Rene C; Lewis, Karl D; Tentler, John J; Tan, Aik Choon; Robinson, William A

2017-06-01

Mucosal melanomas are a rare subtype of melanoma, arising in mucosal tissues, which have a very poor prognosis due to the lack of effective targeted therapies. This study aimed to better understand the molecular landscape of these cancers and find potential new therapeutic targets. Whole-exome sequencing was performed on mucosal melanomas from 19 patients and 135 sun-exposed cutaneous melanomas, with matched peripheral blood samples when available. Mutational profiles were compared between mucosal subgroups and sun-exposed cutaneous melanomas. Comparisons of molecular profiles identified 161 genes enriched in mucosal melanoma (P<0.05). KIT and NF1 were frequently comutated (32%) in the mucosal subgroup, with a significantly higher incidence than that in cutaneous melanoma (4%). Recurrent SF3B1 R625H/S/C mutations were identified and validated in 7 of 19 (37%) mucosal melanoma patients. Mutations in the spliceosome pathway were found to be enriched in mucosal melanomas when compared with cutaneous melanomas. Alternative splicing in four genes were observed in SF3B1-mutant samples compared with the wild-type samples. This study identified potential new therapeutic targets for mucosal melanoma, including comutation of NF1 and KIT, and recurrent R625 mutations in SF3B1. This is the first report of SF3B1 R625 mutations in vulvovaginal mucosal melanoma, with the largest whole-exome sequencing project of mucosal melanomas to date. The results here also indicated that the mutations in SF3B1 lead to alternative splicing in multiple genes. These findings expand our knowledge of this rare disease.

Convergent Evolution of Head Crests in Two Domesticated Columbids Is Associated with Different Missense Mutations in EphB2

PubMed Central

Vickrey, Anna I.; Domyan, Eric T.; Horvath, Martin P.; Shapiro, Michael D.

2015-01-01

Head crests are important display structures in wild bird species and are also common in domesticated lineages. Many breeds of domestic rock pigeon (Columba livia) have crests of reversed occipital feathers, and this recessive trait is associated with a nonsynonymous coding mutation in the intracellular kinase domain of EphB2 (Ephrin receptor B2). The domestic ringneck dove (Streptopelia risoria) also has a recessive crested morph with reversed occipital feathers, and interspecific crosses between crested doves and pigeons produce crested offspring, suggesting a similar genetic basis for this trait in both species. We therefore investigated EphB2 as a candidate for the head crest phenotype of ringneck doves and identified a nonsynonymous coding mutation in the intracellular kinase domain that is significantly associated with the crested morph. This mutation is over 100 amino acid positions away from the crest mutation found in rock pigeons, yet both mutations are predicted to negatively affect the function of ATP-binding pocket. Furthermore, bacterial toxicity assays suggest that “crest” mutations in both species severely impact kinase activity. We conclude that head crests are associated with different mutations in the same functional domain of the same gene in two different columbid species, thereby representing striking evolutionary convergence in morphology and molecules. PMID:26104009

Mutations in COQ8B (ADCK4) found in patients with steroid‐resistant nephrotic syndrome alter COQ8B function

PubMed Central

Vazquez Fonseca, Luis; Doimo, Mara; Calderan, Cristina; Desbats, Maria Andrea; Acosta, Manuel J.; Cerqua, Cristina; Cassina, Matteo; Ashraf, Shazia; Hildebrandt, Friedhelm; Sartori, Geppo; Navas, Placido; Trevisson, Eva

2017-01-01

Abstract Mutations in COQ8B cause steroid‐resistant nephrotic syndrome with variable neurological involvement. In yeast, COQ8 encodes a protein required for coenzyme Q (CoQ) biosynthesis, whose precise role is not clear. Humans harbor two paralog genes: COQ8A and COQ8B (previously termed ADCK3 and ADCK4). We have found that COQ8B is a mitochondrial matrix protein peripherally associated with the inner membrane. COQ8B can complement a ΔCOQ8 yeast strain when its mitochondrial targeting sequence (MTS) is replaced by a yeast MTS. This model was employed to validate COQ8B mutations, and to establish genotype–phenotype correlations. All mutations affected respiratory growth, but there was no correlation between mutation type and the severity of the phenotype. In fact, contrary to the case of COQ2, where residual CoQ biosynthesis correlates with clinical severity, patients harboring hypomorphic COQ8B alleles did not display a different phenotype compared with those with null mutations. These data also suggest that the system is redundant, and that other proteins (probably COQ8A) may partially compensate for the absence of COQ8B. Finally, a COQ8B polymorphism, present in 50% of the European population (NM_024876.3:c.521A > G, p.His174Arg), affects stability of the protein and could represent a risk factor for secondary CoQ deficiencies or for other complex traits. PMID:29194833

Mutation Update and Genotype–Phenotype Correlations of Novel and Previously Described Mutations in TPM2 and TPM3 Causing Congenital Myopathies

PubMed Central

Marttila, Minttu; Lehtokari, Vilma-Lotta; Marston, Steven; Nyman, Tuula A.; Barnerias, Christine; Beggs, Alan H.; Bertini, Enrico; Ceyhan-Birsoy, OÖzge; Cintas, Pascal; Gerard, Marion; Gilbert-Dussardier, Brigitte; Hogue, Jacob S.; Longman, Cheryl; Eymard, Bruno; Frydman, Moshe; Kang, Peter B.; Klinge, Lars; Kolski, Hanna; Lochmüller, Hans; Magy, Laurent; Manel, Véronique; Mayer, Michèle; Mercuri, Eugenio; North, Kathryn N.; Peudenier-Robert, Sylviane; Pihko, Helena; Probst, Frank J.; Reisin, Ricardo; Stewart, Willie; Taratuto, Ana Lia; de Visser, Marianne; Wilichowski, Ekkehard; Winer, John; Nowak, Kristen; Laing, Nigel G.; Winder, Tom L.; Monnier, Nicole; Clarke, Nigel F.; Pelin, Katarina; Grönholm, Mikaela; Wallgren-Pettersson, Carina

2014-01-01

Mutations affecting skeletal muscle isoforms of the tropomyosin genes may cause nemaline myopathy, cap myopathy, core-rod myopathy, congenital fiber-type disproportion, distal arthrogryposes, and Escobar syndrome. We correlate the clinical picture of these diseases with novel (19) and previously reported (31) mutations of the TPM2 and TPM3 genes. Included are altogether 93 families: 53 with TPM2 mutations and 40 with TPM3 mutations. Thirty distinct pathogenic variants of TPM2 and 20 of TPM3 have been published or listed in the Leiden Open Variant Database (http://www.dmd.nl/). Most are heterozygous changes associated with autosomal-dominant disease. Patients with TPM2 mutations tended to present with milder symptoms than those with TPM3 mutations, DA being present only in the TPM2 group. Previous studies have shown that five of the mutations in TPM2 and one in TPM3 cause increased Ca2+ sensitivity resulting in a hypercontractile molecular phenotype. Patients with hypercontractile phenotype more often had contractures of the limb joints (18/19) and jaw (6/19) than those with nonhypercontractile ones (2/22 and 1/22), whereas patients with the non-hypercontractile molecular phenotype more often (19/22) had axial contractures than the hypercontractile group (7/19). Our in silico predictions show that most mutations affect tropomyosin–actin association or tropomyosin head-to-tail binding. PMID:24692096

Aggregation-prone c9FTD/ALS poly(GA) RAN-translated proteins cause neurotoxicity by inducing ER stress.

PubMed

Zhang, Yong-Jie; Jansen-West, Karen; Xu, Ya-Fei; Gendron, Tania F; Bieniek, Kevin F; Lin, Wen-Lang; Sasaguri, Hiroki; Caulfield, Thomas; Hubbard, Jaime; Daughrity, Lillian; Chew, Jeannie; Belzil, Veronique V; Prudencio, Mercedes; Stankowski, Jeannette N; Castanedes-Casey, Monica; Whitelaw, Ena; Ash, Peter E A; DeTure, Michael; Rademakers, Rosa; Boylan, Kevin B; Dickson, Dennis W; Petrucelli, Leonard

2014-10-01

The occurrence of repeat-associated non-ATG (RAN) translation, an atypical form of translation of expanded repeats that results in the synthesis of homopolymeric expansion proteins, is becoming more widely appreciated among microsatellite expansion disorders. Such disorders include amyotrophic lateral sclerosis and frontotemporal dementia caused by a hexanucleotide repeat expansion in the C9ORF72 gene (c9FTD/ALS). We and others have recently shown that this bidirectionally transcribed repeat is RAN translated, and the "c9RAN proteins" thusly produced form neuronal inclusions throughout the central nervous system of c9FTD/ALS patients. Nonetheless, the potential contribution of c9RAN proteins to disease pathogenesis remains poorly understood. In the present study, we demonstrate that poly(GA) c9RAN proteins are neurotoxic and may be implicated in the neurodegenerative processes of c9FTD/ALS. Specifically, we show that expression of poly(GA) proteins in cultured cells and primary neurons leads to the formation of soluble and insoluble high molecular weight species, as well as inclusions composed of filaments similar to those observed in c9FTD/ALS brain tissues. The expression of poly(GA) proteins is accompanied by caspase-3 activation, impaired neurite outgrowth, inhibition of proteasome activity, and evidence of endoplasmic reticulum (ER) stress. Of importance, ER stress inhibitors, salubrinal and TUDCA, provide protection against poly(GA)-induced toxicity. Taken together, our data provide compelling evidence towards establishing RAN translation as a pathogenic mechanism of c9FTD/ALS, and suggest that targeting the ER using small molecules may be a promising therapeutic approach for these devastating diseases.

Mutations in the PDE6B gene in autosomal recessive retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danciger, M.; Blaney, J.; Gao, Y.Q.

1995-11-01

We have studied 24 small families with presumed autosomal recessive inheritance of retinitis pigmentosa by a combination of haplotype analysis and exon screening. Initial analysis of the families was made with a dinucleotide repeat polymorphism adjacent to the gene for rod cGMP-phosphodiesterase (PDE6B). This was followed by denaturing gradient gel electrophoresis (DGGE) and single-strand conformation polymorphism electrophoresis (SSCPE) of the 22 exons and a portion of the 5{prime} untranslated region of the PDE6B gene in the probands of each family in which the PDE6B locus could not be ruled out from segregating with disease. Two probands were found with compoundmore » heterozygous mutations: Gly576Asp and His620(1-bp del) mutations were present in one proband, and a Lys706X null mutation and an AG to AT splice acceptor site mutation in intron 2 were present in the other. Only the affecteds of each of the two families carried both corresponding mutations. 29 refs., 3 figs., 1 tab.« less

Oncogenic PIK3CA gene mutations and HER2/neu gene amplifications determine the sensitivity of uterine serous carcinoma cell lines to GDC-0980, a selective inhibitor of Class I PI3 kinase and mTOR kinase (TORC1/2).

PubMed

English, Diana P; Bellone, Stefania; Cocco, Emiliano; Bortolomai, Ileana; Pecorelli, Sergio; Lopez, Salvatore; Silasi, Dan-Arin; Schwartz, Peter E; Rutherford, Thomas; Santin, Alessandro D

2013-11-01

To evaluate PIK3CA mutational status and c-erbB2 gene amplification in a series of primary uterine serous carcinomas (USC) cell lines. To assess the efficacy of GDC-0980, a potent inhibitor of Class I PI3 kinase and mTOR kinase (TORC1/2), against primary USC harboring HER2/neu gene amplification and/or PIK3CA mutations. Twenty-two primary USC cell lines were evaluated for c-erbB2 oncogene amplification by fluorescence in situ hybridization (FISH) assays and for PIK3CA gene mutations by direct DNA sequencing of exons 9 and 20. In vitro sensitivity to GDC-0980 was evaluated by flow-cytometry-based viability and proliferation assays. Downstream cellular responses to GDC-0980 were assessed by measuring phosphorylation of the 4-EBP1 protein by flow-cytometry. Five of 22 (22.7%) USC cell lines contained oncogenic PIK3CA mutations although 9 (40.9%) harbored c-erbB2 gene amplification by FISH. GDC-0980 caused a strong differential growth inhibition in FISH+ USC when compared with FISH- (GDC-0980 IC50 mean ± SEM = 0.29 ± 0.05 μM in FISH+ vs 1.09 ± 0.20 μM in FISH- tumors, P = .02). FISH+ USC harboring PIK3CA mutations were significantly more sensitive to GDC-0980 exposure when compared with USC cell lines harboring wild-type PIK3CA (P = .03). GDC-0980 growth-inhibition was associated with a significant and dose-dependent decline in phosphorylated 4-EBP1 levels. Oncogenic PIK3CA mutations and c-erbB2 gene amplification may represent biomarkers to identify patients harboring USC who may benefit most from the use of GDC-0980. Copyright © 2013 Mosby, Inc. All rights reserved.

MYO5B, STX3, and STXBP2 mutations reveal a common disease mechanism that unifies a subset of congenital diarrheal disorders: A mutation update

PubMed Central

Dhekne, Herschel S.; Pylypenko, Olena; Overeem, Arend W.; Ferreira, Rosaria J.; van der Velde, K. Joeri; Rings, Edmond H.H.M.; Posovszky, Carsten; Swertz, Morris A.; Houdusse, Anne

2018-01-01

Abstract Microvillus inclusion disease (MVID) is a rare but fatal autosomal recessive congenital diarrheal disorder caused by MYO5B mutations. In 2013, we launched an open‐access registry for MVID patients and their MYO5B mutations (www.mvid-central.org). Since then, additional unique MYO5B mutations have been identified in MVID patients, but also in non‐MVID patients. Animal models have been generated that formally prove the causality between MYO5B and MVID. Importantly, mutations in two other genes, STXBP2 and STX3, have since been associated with variants of MVID, shedding new light on the pathogenesis of this congenital diarrheal disorder. Here, we review these additional genes and their mutations. Furthermore, we discuss recent data from cell studies that indicate that the three genes are functionally linked and, therefore, may constitute a common disease mechanism that unifies a subset of phenotypically linked congenital diarrheal disorders. We present new data based on patient material to support this. To congregate existing and future information on MVID geno‐/phenotypes, we have updated and expanded the MVID registry to include all currently known MVID‐associated gene mutations, their demonstrated or predicted functional consequences, and associated clinical information. PMID:29266534

Mutational Studies Uncover Non-Native Structure in the Dimeric Kinetic Intermediate of the H2A-H2B Heterodimer

PubMed Central

Stump, Matthew R.; Gloss, Lisa M.

2010-01-01

The folding pathway of the histone H2A-H2B heterodimer minimally includes an on-pathway, dimeric, burst-phase intermediate, I2. The partially folded H2A and H2B monomers populated at equilibrium were characterized as potential monomeric kinetic intermediates. Folding kinetics were compared for initiation from isolated, folded monomers and the heterodimer unfolded in 4 M urea. The observed rates were virtually identical above 0.4 M urea, exhibiting a log-linear relationship on the final denaturant concentration. Below ~0.4 M urea (concentrations inaccessible from the 4 M urea unfolded state), a roll-over in the rates was observed; this suggests that a component of the I2 ensemble contains non-native structure that rearranges/isomerizes to a more native-like species. The contribution of helix propensity to the stability of the I2 ensemble was assessed with a set of H2A-H2B mutants containing Ala and Gly replacements at nine sites, focusing mainly on the long, central α2 helix. Equilibrium and kinetic folding/unfolding data were collected to determine the effects of the mutations on the stability of I2 and the transition state between I2 and N2. This limited mutational study indicated that residues in the α2 helices of H2A and H2B, as well as α1 of H2B and both the C-terminus of α3 and the short αC helix of H2A contribute to the stability of the I2 burst phase species. Interestingly, at least eight of the nine targeted residues stabilize I2 by interactions that are non-native to some extent. Given that destabilizing I2 and these non-native interactions does not accelerate folding, it is concluded that the native and non-native structure present in the I2 ensemble enables efficient folding of H2A-H2B. PMID:20600120

Whole-exome sequencing identifies recurrent SF3B1 R625 mutation and comutation of NF1 and KIT in mucosal melanoma

PubMed Central

Hintzsche, Jennifer D.; Gorden, Nicholas T.; Amato, Carol M.; Kim, Jihye; Wuensch, Kelsey E.; Robinson, Steven E.; Applegate, Allison J.; Couts, Kasey L.; Medina, Theresa M.; Wells, Keith R.; Wisell, Joshua A.; McCarter, Martin D.; Box, Neil F.; Shellman, Yiqun G.; Gonzalez, Rene C.; Lewis, Karl D.; Tentler, John J.

2017-01-01

Mucosal melanomas are a rare subtype of melanoma, arising in mucosal tissues, which have a very poor prognosis due to the lack of effective targeted therapies. This study aimed to better understand the molecular landscape of these cancers and find potential new therapeutic targets. Whole-exome sequencing was performed on mucosal melanomas from 19 patients and 135 sun-exposed cutaneous melanomas, with matched peripheral blood samples when available. Mutational profiles were compared between mucosal subgroups and sun-exposed cutaneous melanomas. Comparisons of molecular profiles identified 161 genes enriched in mucosal melanoma (P<0.05). KIT and NF1 were frequently comutated (32%) in the mucosal subgroup, with a significantly higher incidence than that in cutaneous melanoma (4%). Recurrent SF3B1 R625H/S/C mutations were identified and validated in 7 of 19 (37%) mucosal melanoma patients. Mutations in the spliceosome pathway were found to be enriched in mucosal melanomas when compared with cutaneous melanomas. Alternative splicing in four genes were observed in SF3B1-mutant samples compared with the wild-type samples. This study identified potential new therapeutic targets for mucosal melanoma, including comutation of NF1 and KIT, and recurrent R625 mutations in SF3B1. This is the first report of SF3B1 R625 mutations in vulvovaginal mucosal melanoma, with the largest whole-exome sequencing project of mucosal melanomas to date. The results here also indicated that the mutations in SF3B1 lead to alternative splicing in multiple genes. These findings expand our knowledge of this rare disease. PMID:28296713

SPE-GC/FTD determination of N-methyl-2-pyrrolidone and its metabolites in urine.

PubMed

Kubota, Ryuichi; Endo, Yoko; Takeuchi, Akito; Inoue, Yoshinori; Ogata, Hiroko; Ogawa, Masanori; Nakagawa, Tomoo; Onda, Nobuhiko; Endo, Ginji

2007-07-01

An analytical method using a combination of solid-phase extraction (SPE) and gas chromatography with a flame thermionic detector (GC/FTD) was developed for determination of N-methyl-2-pyrrolidone (NMP), N-methylsuccinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine. The SPE cartridge of poly(divinylbenzene/hydroxymethacrylate) used was directly loaded with urine sample, followed by elution with methyl isobutyl ketone (MIBK) and subsequent centrifugation, and the supernatant was injected into the capillary GC using a DB1701. This method allowed efficient separation of NMP, MSI, and 2-HMSI, which were nearly free of interference by other GC peaks arising from urine. Recoveries of NMP, MSI, and 2-HMSI from the SPE cartridge were about 98, 101, and 67%, respectively, with limits of detection of 0.04, 0.02, and 0.06 mg/L, respectively, which met the regulatory requirements. The present method was used for assay in biological monitoring of workers exposed to NMP in their occupational environment.

A novel dominant GJB2 (DFNA3) mutation in a Chinese family

NASA Astrophysics Data System (ADS)

Wang, Hongyang; Wu, Kaiwen; Yu, Lan; Xie, Linyi; Xiong, Wenping; Wang, Dayong; Guan, Jing; Wang, Qiuju

2017-01-01

To decipher the phenotype and genotype of a Chinese family with autosomal dominant non-syndromic hearing loss (ADNSHL) and a novel dominant missense mutation in the GJB2 gene (DFNA3), mutation screening of GJB2 was performed on the propositus from a five-generation ADNSHL family through polymerase chain reaction amplification and Sanger sequencing. The candidate variation and the co-segregation of the phenotype were verified in all ascertained family members. Targeted genes capture and next-generation sequencing (NGS) were performed to explore additional genetic variations. We identified the novel GJB2 mutation c.524C > A (p.P175H), which segregated with high frequency and was involved in progressive sensorineural hearing loss. One subject with an additional c.235delC mutation showed a more severe phenotype than did the other members with single GJB2 dominant variations. Four patients diagnosed with noise-induced hearing loss did not carry this mutation. No other pathogenic variations or modifier genes were identified by NGS. In conclusion, a novel missense mutation in GJB2 (DFNA3), affecting the second extracellular domain of the protein, was identified in a family with ADNSHL.

CYP1B1 and MYOC Mutations in Vietnamese Primary Congenital Glaucoma Patients.

PubMed

Do, Tan; Shei, William; Chau, Pham Thi Minh; Trang, Doan Le; Yong, Victor H K; Ng, Xiao Yu; Chen, Yue Ming; Aung, Tin; Vithana, Eranga N

2016-05-01

Primary congenital glaucoma (PCG, OMIM 231300), the most common glaucoma in infancy, is caused by developmental defects in the anterior chamber angle. The 3 implicated genes are cytochrome P450 family I subfamily B polypeptide 1 (CYP1B1), latent transforming growth factor β-binding protein 2 (LTBP2), and myocilin (MYOC). In this study, we sought to determine CYP1B1 and MYOC sequence variations in a Vietnamese cohort of index cases with PCG and their families. Thirty Vietnamese subjects with PCG and 120 normal Vietnamese subjects were recruited. PCG was defined by the presence of at least 2 of the following clinical manifestations: increased corneal diameter (>10 mm at birth), corneal edema, Haab's striae, optic disc changes, and absence of other ocular or systemic diseases associated with childhood glaucoma. The coding exons, intron and exon boundaries, and untranslated regions of CYP1B1 and MYOC genes were PCR amplified and subjected to bidirectional sequencing in all subjects. We identified 2 homozygous and 3 heterozygous CYP1B1 sequence alterations in our study subjects. Among the 5 mutations identified, 2 (p.H279L and p.L283F) were novel mutations, whereas 3 (p.A121_S122insDRPAFA, p.L107V, and p.V320L) had been previously reported in PCG cases. None of these mutations was observed in any of the 120 controls. Haplotypes generated with 6 non-disease-causing intragenic single nucleotide polymorphisms detected in CYP1B1 indicated that the most common haplotype in Vietnamese population is similar to that found in Chinese and Japanese. The genotype-phenotype correlation showed no significant difference between mutation and no-mutation groups for quantitative clinical features (presenting intraocular pressure, corneal diameter, number of surgeries performed, the cup-to-disc ratio) as well as for qualitative factors (bilateral cases, phenotype severity, and the prognosis) (P>0.05). Five out of 30 families with PCG (16.7%) had disease attributable to CYP1B1 alterations

Mutational Analysis of the Adaptor Protein 2 Sigma Subunit (AP2S1) Gene: Search for Autosomal Dominant Hypocalcemia Type 3 (ADH3)

PubMed Central

Rogers, Angela; Nesbit, M. Andrew; Hannan, Fadil M.; Howles, Sarah A.; Gorvin, Caroline M.; Cranston, Treena; Allgrove, Jeremy; Bevan, John S.; Bano, Gul; Brain, Caroline; Datta, Vipan; Grossman, Ashley B.; Hodgson, Shirley V.; Izatt, Louise; Millar-Jones, Lynne; Pearce, Simon H.; Robertson, Lisa; Selby, Peter L.; Shine, Brian; Snape, Katie; Warner, Justin

2014-01-01

Context: Autosomal dominant hypocalcemia (ADH) types 1 and 2 are due to calcium-sensing receptor (CASR) and G-protein subunit-α11 (GNA11) gain-of-function mutations, respectively, whereas CASR and GNA11 loss-of-function mutations result in familial hypocalciuric hypercalcemia (FHH) types 1 and 2, respectively. Loss-of-function mutations of adaptor protein-2 sigma subunit (AP2σ 2), encoded by AP2S1, cause FHH3, and we therefore sought for gain-of-function AP2S1 mutations that may cause an additional form of ADH, which we designated ADH3. Objective: The objective of the study was to investigate the hypothesis that gain-of-function AP2S1 mutations may cause ADH3. Design: The sample size required for the detection of at least one mutation with a greater than 95% likelihood was determined by binomial probability analysis. Nineteen patients (including six familial cases) with hypocalcemia in association with low or normal serum PTH concentrations, consistent with ADH, but who did not have CASR or GNA11 mutations, were ascertained. Leukocyte DNA was used for sequence and copy number variation analysis of AP2S1. Results: Binomial probability analysis, using the assumption that AP2S1 mutations would occur in hypocalcemic patients at a prevalence of 20%, which is observed in FHH patients without CASR or GNA11 mutations, indicated that the likelihood of detecting at least one AP2S1 mutation was greater than 95% and greater than 98% in sample sizes of 14 and 19 hypocalcemic patients, respectively. AP2S1 mutations and copy number variations were not detected in the 19 hypocalcemic patients. Conclusion: The absence of AP2S1 abnormalities in hypocalcemic patients, suggests that ADH3 may not occur or otherwise represents a rare hypocalcemic disorder. PMID:24708097

Mutations of NOTCH3 in childhood pulmonary arterial hypertension

PubMed Central

Chida, Ayako; Shintani, Masaki; Matsushita, Yoshihisa; Sato, Hiroki; Eitoku, Takahiro; Nakayama, Tomotaka; Furutani, Yoshiyuki; Hayama, Emiko; Kawamura, Yoichi; Inai, Kei; Ohtsuki, Shinichi; Saji, Tsutomu; Nonoyama, Shigeaki; Nakanishi, Toshio

2014-01-01

Mutations of BMPR2 and other TGF-β superfamily genes have been reported in pulmonary arterial hypertension (PAH). However, 60–90% of idiopathic PAH cases have no mutations in these genes. Recently, the expression of NOTCH3 was shown to be increased in the pulmonary artery smooth muscle cells of PAH patients. We sought to investigate NOTCH3 and its target genes in PAH patients and clarify the role of NOTCH3 signaling. We screened for mutations in NOTCH3, HES1, and HES5 in 41 PAH patients who had no mutations in BMPR2, ALK1, endoglin, SMAD1/4/8, BMPR1B, or Caveolin-1. Two novel missense mutations (c.2519 G>A p.G840E, c.2698 A>C p.T900P) in NOTCH3 were identified in two PAH patients. We performed functional analysis using stable cell lines expressing either wild-type or mutant NOTCH3. The protein-folding chaperone GRP78/BiP was colocalized with wild-type NOTCH3 in the endoplasmic reticulum, whereas the majority of GRP78/BiP was translocated into the nuclei of cells expressing mutant NOTCH3. Cell proliferation and viability were higher for cells expressing mutant NOTCH3 than for those expressing wild-type NOTCH3. We identified novel NOTCH3 mutations in PAH patients and revealed that these mutations were involved in cell proliferation and viability. NOTCH3 mutants induced an impairment in NOTCH3-HES5 signaling. The results may contribute to the elucidation of PAH pathogenesis. PMID:24936512

[A novel M142T mutation in the B glycosyltransferase gene associated with B3 variant in Chinese].

PubMed

Xu, Xian-guo; Hong, Xiao-zhen; Liu, Ying; Zhu, Fa-ming; Lv, Hang-jun; Yan, Li-xing

2009-06-01

To investigate the molecular genetic basis of the B3 variant of ABO blood group system with mixed-field hemagglutination in Chinese. Serological techniques were performed to characterize the erythrocyte phenotype of two discrepant samples. A sequential agglutination method and 13 short tandem repeat (STR) loci were tested to exclude the possibility of exogenous or endogenous DNA chimera. Mutations in exons 6 and 7, including partial intron of the ABO gene, were screened by polymerase chain reaction and DNA sequencing. Haplotypes of the two individuals were also analyzed by sequencing. A mixed-field hemagglutination of RBCs with anti-B and anti-AB antibodies was detected in the two unrelated individuals. Exogenous ABO-incompatible RBC transfusion and endogenous genetic chimera were excluded by sequential agglutination method and STR. The ABO phenotypes of the two individuals were classified as A1B3 according to the ABO subgroup definition. The sequence region from intron 5 to 3'-UTR of the B allele was identical to that of ABO*B101 allele, except for a T to C substitution at nucleotide position 425 in exon 7. This substitution resulted in an amino acid change of M142T in the B glycosyltransferase. A novel B allele with 425T>C substitution resulting in B3 subgroup was identified in two Chinese individuals.

The most prevalent genetic cause of ALS-FTD, C9orf72 synergizes the toxicity of ATXN2 intermediate polyglutamine repeats through the autophagy pathway

PubMed Central

Ciura, Sorana; Sellier, Chantal; Campanari, Maria-Letizia; Charlet-Berguerand, Nicolas; Kabashi, Edor

2016-01-01

ABSTRACT The most common genetic cause for amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD) is repeat expansion of a hexanucleotide sequence (GGGGCC) within the C9orf72 genomic sequence. To elucidate the functional role of C9orf72 in disease pathogenesis, we identified certain molecular interactors of this factor. We determined that C9orf72 exists in a complex with SMCR8 and WDR41 and that this complex acts as a GDP/GTP exchange factor for RAB8 and RAB39, 2 RAB GTPases involved in macroautophagy/autophagy. Consequently, C9orf72 depletion in neuronal cultures leads to accumulation of unresolved aggregates of SQSTM1/p62 and phosphorylated TARDBP/TDP-43. However, C9orf72 reduction does not lead to major neuronal toxicity, suggesting that a second stress may be required to induce neuronal cell death. An intermediate size of polyglutamine repeats within ATXN2 is an important genetic modifier of ALS-FTD. We found that coexpression of intermediate polyglutamine repeats (30Q) of ATXN2 combined with C9orf72 depletion increases the aggregation of ATXN2 and neuronal toxicity. These results were confirmed in zebrafish embryos where partial C9orf72 knockdown along with intermediate (but not normal) repeat expansions in ATXN2 causes locomotion deficits and abnormal axonal projections from spinal motor neurons. These results demonstrate that C9orf72 plays an important role in the autophagy pathway while genetically interacting with another major genetic risk factor, ATXN2, to contribute to ALS-FTD pathogenesis. PMID:27245636

The most prevalent genetic cause of ALS-FTD, C9orf72 synergizes the toxicity of ATXN2 intermediate polyglutamine repeats through the autophagy pathway.

PubMed

Ciura, Sorana; Sellier, Chantal; Campanari, Maria-Letizia; Charlet-Berguerand, Nicolas; Kabashi, Edor

2016-08-02

The most common genetic cause for amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD) is repeat expansion of a hexanucleotide sequence (GGGGCC) within the C9orf72 genomic sequence. To elucidate the functional role of C9orf72 in disease pathogenesis, we identified certain molecular interactors of this factor. We determined that C9orf72 exists in a complex with SMCR8 and WDR41 and that this complex acts as a GDP/GTP exchange factor for RAB8 and RAB39, 2 RAB GTPases involved in macroautophagy/autophagy. Consequently, C9orf72 depletion in neuronal cultures leads to accumulation of unresolved aggregates of SQSTM1/p62 and phosphorylated TARDBP/TDP-43. However, C9orf72 reduction does not lead to major neuronal toxicity, suggesting that a second stress may be required to induce neuronal cell death. An intermediate size of polyglutamine repeats within ATXN2 is an important genetic modifier of ALS-FTD. We found that coexpression of intermediate polyglutamine repeats (30Q) of ATXN2 combined with C9orf72 depletion increases the aggregation of ATXN2 and neuronal toxicity. These results were confirmed in zebrafish embryos where partial C9orf72 knockdown along with intermediate (but not normal) repeat expansions in ATXN2 causes locomotion deficits and abnormal axonal projections from spinal motor neurons. These results demonstrate that C9orf72 plays an important role in the autophagy pathway while genetically interacting with another major genetic risk factor, ATXN2, to contribute to ALS-FTD pathogenesis.

LMX1B Mutations Cause Hereditary FSGS without Extrarenal Involvement

PubMed Central

Boyer, Olivia; Woerner, Stéphanie; Yang, Fan; Oakeley, Edward J.; Linghu, Bolan; Gribouval, Olivier; Tête, Marie-Josèphe; Duca, José S.; Klickstein, Lloyd; Damask, Amy J.; Szustakowski, Joseph D.; Heibel, Françoise; Matignon, Marie; Baudouin, Véronique; Chantrel, François; Champigneulle, Jacqueline; Martin, Laurent; Nitschké, Patrick; Gubler, Marie-Claire; Johnson, Keith J.; Chibout, Salah-Dine

2013-01-01

LMX1B encodes a homeodomain-containing transcription factor that is essential during development. Mutations in LMX1B cause nail-patella syndrome, characterized by dysplasia of the patellae, nails, and elbows and FSGS with specific ultrastructural lesions of the glomerular basement membrane (GBM). By linkage analysis and exome sequencing, we unexpectedly identified an LMX1B mutation segregating with disease in a pedigree of five patients with autosomal dominant FSGS but without either extrarenal features or ultrastructural abnormalities of the GBM suggestive of nail-patella–like renal disease. Subsequently, we screened 73 additional unrelated families with FSGS and found mutations involving the same amino acid (R246) in 2 families. An LMX1B in silico homology model suggested that the mutated residue plays an important role in strengthening the interaction between the LMX1B homeodomain and DNA; both identified mutations would be expected to diminish such interactions. In summary, these results suggest that isolated FSGS could result from mutations in genes that are also involved in syndromic forms of FSGS. This highlights the need to include these genes in all diagnostic approaches to FSGS that involve next-generation sequencing. PMID:23687361

Mutational characterization of the P3H1/CRTAP/CypB complex in recessive osteogenesis imperfecta.

PubMed

Barbirato, C; Trancozo, M; Almeida, M G; Almeida, L S; Santos, T O; Duarte, J C G; Rebouças, M R G O; Sipolatti, V; Nunes, V R R; Paula, F

2015-12-03

Osteogenesis imperfecta (OI) is a genetic disease characterized by bone deformities and fractures. Most cases are caused by autosomal dominant mutations in the type I collagen genes COL1A1 and COL1A2; however, an increasing number of recessive mutations in other genes have been reported. The LEPRE1, CRTAP, and PPIB genes encode proteins that form the P3H1/CRTAP/CypB complex, which is responsible for posttranslational modifications of type I collagen. In general, mutations in these genes lead to severe and lethal phenotypes of recessive OI. Here, we describe sixteen genetic variations detected in LEPRE1, CRTAP, and PPIB from 25 Brazilian patients with OI. Samples were screened for mutations on single-strand conformation polymorphism gels and variants were determined by automated sequencing. Seven variants were detected in patients but were absent in control samples. LEPRE1 contained the highest number of variants, including the previously described West African allele (c.1080+1G>T) found in one patient with severe OI as well as a previously undescribed p.Trp675Leu change that is predicted to be disease causing. In CRTAP, one patient carried the c.558A>G homozygous mutation, predicted as disease causing through alteration of a splice site. Genetic variations detected in the PPIB gene are probably not pathogenic due to their localization or because of their synonymous effect. This study enhances our knowledge about the mutational pattern of the LEPRE1, CRTAP, and PPIB genes. In addition, the results strengthen the proposition that LEPRE1 should be the first gene analyzed in mutation detection studies in patients with recessive OI.

The CDC Hemophilia B mutation project mutation list: a new online resource.

PubMed

Li, Tengguo; Miller, Connie H; Payne, Amanda B; Craig Hooper, W

2013-11-01

Hemophilia B (HB) is caused by mutations in the human gene F9. The mutation type plays a pivotal role in genetic counseling and prediction of inhibitor development. To help the HB community understand the molecular etiology of HB, we have developed a listing of all F9 mutations that are reported to cause HB based on the literature and existing databases. The Centers for Disease Control and Prevention (CDC) Hemophilia B Mutation Project (CHBMP) mutation list is compiled in an easily accessible format of Microsoft Excel and contains 1083 unique mutations that are reported to cause HB. Each mutation is identified using Human Genome Variation Society (HGVS) nomenclature standards. The mutation types and the predicted changes in amino acids, if applicable, are also provided. Related information including the location of mutation, severity of HB, the presence of inhibitor, and original publication reference are listed as well. Therefore, our mutation list provides an easily accessible resource for genetic counselors and HB researchers to predict inhibitors. The CHBMP mutation list is freely accessible at http://www.cdc.gov/hemophiliamutations.

Convergent Evolution of Head Crests in Two Domesticated Columbids Is Associated with Different Missense Mutations in EphB2.

PubMed

Vickrey, Anna I; Domyan, Eric T; Horvath, Martin P; Shapiro, Michael D

2015-10-01

Head crests are important display structures in wild bird species and are also common in domesticated lineages. Many breeds of domestic rock pigeon (Columba livia) have crests of reversed occipital feathers, and this recessive trait is associated with a nonsynonymous coding mutation in the intracellular kinase domain of EphB2 (Ephrin receptor B2). The domestic ringneck dove (Streptopelia risoria) also has a recessive crested morph with reversed occipital feathers, and interspecific crosses between crested doves and pigeons produce crested offspring, suggesting a similar genetic basis for this trait in both species. We therefore investigated EphB2 as a candidate for the head crest phenotype of ringneck doves and identified a nonsynonymous coding mutation in the intracellular kinase domain that is significantly associated with the crested morph. This mutation is over 100 amino acid positions away from the crest mutation found in rock pigeons, yet both mutations are predicted to negatively affect the function of ATP-binding pocket. Furthermore, bacterial toxicity assays suggest that "crest" mutations in both species severely impact kinase activity. We conclude that head crests are associated with different mutations in the same functional domain of the same gene in two different columbid species, thereby representing striking evolutionary convergence in morphology and molecules. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

MPL mutation profile in JAK2 mutation-negative patients with myeloproliferative disorders.

PubMed

Ma, Wanlong; Zhang, Xi; Wang, Xiuqiang; Zhang, Zhong; Yeh, Chen-Hsiung; Uyeji, Jennifer; Albitar, Maher

2011-03-01

Mutations in the thrombopoietin receptor gene (myeloproliferative leukemia, MPL) have been reported in patients with JAK2 V617F-negative chronic myeloproliferative disorders (MPDs). We evaluated the prevalence of MPL mutations relative to JAK2 mutations in patients with suspected MPDs. A total of 2790 patient samples submitted for JAK2 mutation analysis were tested using real-time polymerase chain reaction and bidirectional sequencing of plasma RNA. JAK2 V617F-negative samples were tested for JAK2 exons 12 to 14 mutations, and those with negative results were then tested for mutations in MPL exons 10 and 11. Of the 2790 patients, 529 (18.96%) had V617F, 12 (0.43%) had small insertions or deletions in exon 12, and 7 (0.25%) had other JAK2 mutations in exons 12 to 14. Of the 2242 JAK2 mutation-negative patients, 68 (3.03%) had MPL mutations. W515L was the predominant MPL mutation (n=46; 68%), and 10 (15%) patients had other W515 variants. The remaining MPL mutations (n=12, 17%) were detected at other locations in exons 10 and 11 and included 3 insertion/deletion mutations. The S505N mutation, associated with familial MPD, was detected in 3 patients. Overall, for every 100 V617F mutations in patients with suspected MPDs, there were 12.9 MPL mutations, 2.3 JAK2 exon 12 mutations, and 1.3 JAK2 exons 13 to 14 mutations. These findings suggest that MPL mutation screening should be performed before JAK2 exons 12 to 14 testing in JAK2 V617F-negative patients with suspected MPDs.

Abnormal Expressions of DNA Glycosylase Genes NEIL1, NEIL2, and NEIL3 Are Associated with Somatic Mutation Loads in Human Cancer.

PubMed

Shinmura, Kazuya; Kato, Hisami; Kawanishi, Yuichi; Igarashi, Hisaki; Goto, Masanori; Tao, Hong; Inoue, Yusuke; Nakamura, Satoki; Misawa, Kiyoshi; Mineta, Hiroyuki; Sugimura, Haruhiko

2016-01-01

The effects of abnormalities in the DNA glycosylases NEIL1, NEIL2, and NEIL3 on human cancer have not been fully elucidated. In this paper, we found that the median somatic total mutation loads and the median somatic single nucleotide mutation loads exhibited significant inverse correlations with the median NEIL1 and NEIL2 expression levels and a significant positive correlation with the median NEIL3 expression level using data for 13 cancer types from the Cancer Genome Atlas (TCGA) database. A subset of the cancer types exhibited reduced NEIL1 and NEIL2 expressions and elevated NEIL3 expression, and such abnormal expressions of NEIL1, NEIL2, and NEIL3 were also significantly associated with the mutation loads in cancer. As a mechanism underlying the reduced expression of NEIL1 in cancer, the epigenetic silencing of NEIL1 through promoter hypermethylation was found. Finally, we investigated the reason why an elevated NEIL3 expression level was associated with an increased number of somatic mutations in cancer and found that NEIL3 expression was positively correlated with the expression of APOBEC3B, a potent inducer of mutations, in diverse cancers. These results suggested that the abnormal expressions of NEIL1, NEIL2, and NEIL3 are involved in cancer through their association with the somatic mutation load.

Enhancement of carer skills and patient function in the non-pharmacological management of frontotemporal dementia (FTD): A call for randomised controlled studies

PubMed Central

O'Connor, Claire M.; Clemson, Lindy; da Silva, Thaís Bento Lima; Piguet, Olivier; Hodges, John R.; Mioshi, Eneida

2013-01-01

FTD is a unique condition which manifests with a range of behavioural symptoms, marked dysfunction in activities of daily living (ADL) and increased levels of carer burden as compared to carers of other dementias. No efficacious pharmacological interventions to treat FTD currently exist, and research on pharmacological symptom management is variable. The few studies on non-pharmacological interventions in FTD focus on either the carer or the patients' symptoms, and lack methodological rigour. This paper reviews and discusses current studies utilising non-pharmacological approaches, exposing the clear need for more rigorous methodologies to be applied in this field. Finally, a successful randomised controlled trial helped reduce behaviours of concern in dementia, and through implementing participation in tailored activities, the FTD-specific Tailored Activities Program (TAP) is presented. Crucially, this protocol has scope to target both the person with FTD and their carer. This paper highlights that studies in this area would help to elucidate the potential for using activities to reduce characteristic behaviours in FTD, improving quality of life and the caregiving experience in FTD. PMID:29213832

FGFR2 Point Mutations in 466 Endometrioid Endometrial Tumors: Relationship with MSI, KRAS, PIK3CA, CTNNB1 Mutations and Clinicopathological Features

PubMed Central

Powell, Matthew A.; Wellens, Candice L.; Gao, Feng; Mutch, David G.; Goodfellow, Paul J.; Pollock, Pamela M.

2012-01-01

Mutations in multiple oncogenes including KRAS, CTNNB1, PIK3CA and FGFR2 have been identified in endometrial cancer. The aim of this study was to provide insight into the clinicopathological features associated with patterns of mutation in these genes, a necessary step in planning targeted therapies for endometrial cancer. 466 endometrioid endometrial tumors were tested for mutations in FGFR2, KRAS, CTNNB1, and PIK3CA. The relationships between mutation status, tumor microsatellite instability (MSI) and clinicopathological features including overall survival (OS) and disease-free survival (DFS) were evaluated using Kaplan-Meier survival analysis and Cox proportional hazard models. Mutations were identified in FGFR2 (48/466); KRAS (87/464); CTNNB1 (88/454) and PIK3CA (104/464). KRAS and FGFR2 mutations were significantly more common, and CTNNB1 mutations less common, in MSI positive tumors. KRAS and FGFR2 occurred in a near mutually exclusive pattern (p = 0.05) and, surprisingly, mutations in KRAS and CTNNB1 also occurred in a near mutually exclusive pattern (p = 0.0002). Multivariate analysis revealed that mutation in KRAS and FGFR2 showed a trend (p = 0.06) towards longer and shorter DFS, respectively. In the 386 patients with early stage disease (stage I and II), FGFR2 mutation was significantly associated with shorter DFS (HR = 3.24; 95% confidence interval, CI, 1.35–7.77; p = 0.008) and OS (HR = 2.00; 95% CI 1.09–3.65; p = 0.025) and KRAS was associated with longer DFS (HR = 0.23; 95% CI 0.05–0.97; p = 0.045). In conclusion, although KRAS and FGFR2 mutations share similar activation of the MAPK pathway, our data suggest very different roles in tumor biology. This has implications for the implementation of anti-FGFR or anti-MEK biologic therapies. PMID:22383975

Mutated PPP1R3B is recognized by T cells used to treat a melanoma patient who experienced a durable complete tumor regression

PubMed Central

Lu, Yong-Chen; Yao, Xin; Li, Yong F.; El-Gamil, Mona; Dudley, Mark E.; Yang, James C.; Almeida, Jorge R.; Douek, Daniel C.; Samuels, Yardena; Rosenberg, Steven A.; Robbins, Paul F.

2013-01-01

Adoptive cell therapy with tumor infiltrating lymphocytes (TILs) represents an effective treatment for patients with metastatic melanoma. However, most of the antigen targets recognized by effective melanoma reactive TILs remain elusive. In this study, patient 2369 experienced a complete response, including regressions of bulky liver tumor masses ongoing beyond seven years following adoptive TILs transfer. The screening of a cDNA library generated from the autologous melanoma cell line resulted in the isolation of a mutated PPP1R3B (protein phosphatase 1, regulatory (inhibitor) subunit 3B) gene product. The mutated PPP1R3B peptide represents the immunodominant epitope recognized by tumor reactive T cells in TIL 2369. Five years following adoptive transfer, peripheral blood T lymphocytes obtained from patient 2369 recognized the mutated PPP1R3B epitope. These results demonstrate that adoptive T cell therapy targeting a tumor-specific antigen can mediate long-term survival for a patient with metastatic melanoma. This study also provides an impetus to develop personalized immunotherapy targeting tumor-specific, mutated antigens. PMID:23690473

No exonic mutations at GJB2, GJB3, GJB4, GJB6, ARS (Component B), and LOR genes responsible for a Chinese patient affected by progressive symmetric erythrokeratodermia with pseudoainhum.

PubMed

Zhou, Fusheng; Fu, Hongyang; Liu, Linghua; Cui, Yong; Zhang, Zhengzhong; Chang, Ruixue; Yue, Zhen; Yang, Sen; Zhang, Xuejun

2014-09-01

Progressive symmetric erythrokeratodermia (PSEK) is characterized by symmetric and growing erythematous hyperkeratotic patches over the body shortly after birth, particularly trunk and limbs, the buttocks, and the face, sometimes together with palmoplantar keratoderma (PPK). The GJB2, GJB3, GJB4, GJB6, ARS (Component B), and LOR gene mutation might contribute to PSEK manifestation. This study aimed to identify sequence alteration of these genes in a Chinese PSEK patient with pseudoainhum. Genomic DNA was purified from the patient's peripheral blood. Mutation analysis of target genes was performed by direct sequencing using ABI 3730 sequencer No exonic mutations was identified in the aforementioned genes. The result underlines the genetic heterogeneity of PSEK and other related erythrokeratodermas. © 2014 The International Society of Dermatology.

CNGA3 mutations in two United Arab Emirates families with achromatopsia.

PubMed

Ahuja, Yachna; Kohl, Susanne; Traboulsi, Elias I

2008-07-10

ACHROMATOPSIA RESULTS FROM MUTATIONS IN ONE OF THREE GENES: cyclic nucleotide-gated channel, alpha-3 (CNGA3); cyclic nucleotide-gated channel, beta-3 (CNGB3); and guanine nucleotide-binding protein, alpha-transducing activity polypeptide 2 (GNAT2). We report the responsible mutations in two United Arab Emirates families who have this autosomal recessive disease. Clinical examinations were performed in seven patients from three nuclear families. Molecular genetic testing for common CNGA3 and CNGB3 mutations was undertaken using standard protocols. All patients were extremely light sensitive and had reduced visual acuity and no color perception. Fundus examinations did not show any visible abnormalities. After further pedigree analysis, two of the families were found to be linked through the paternal line. Two mutations in CNGA3 were identified: Arg283Trp and Gly397Val. Family A, the larger pedigree, had one branch in which two sisters and one brother were homozygous for the Gly397Val mutation and another branch in which a brother and sister were compound heterozygous for both aforenamed mutations. Family B, however, only had two brothers who were homozygous for the Arg283Trp mutation. Achromatopsia in these two United Arab Emirates families results from two different mutations in CNGA3. Two branches of the same pedigree had individuals with both homozygous and compound heterozygous disease, demonstrating a complex molecular pathology in this large family.

Hepatitis B virus genetic mutations and evolution in liver diseases

PubMed Central

Shen, Tao; Yan, Xin-Min

2014-01-01

Hepatitis B virus (HBV) belongs to the genus Orthohepadnavirus of the Hepadnaviridae family and is approximately 3.2 kb in length. Owing to a lack of proofreading capacity during reverse transcription and a high replication rate, HBV exhibits as quasispecies. To detect the genetic mutations of HBV, many methods with different sensitivities and throughputs were developed. According to documentary records, HBV mutation and evolution were important vial parameters in predicting disease progression and therapeutic outcome. In this review, we separately discussed the correlation between HBV genomic mutations in four open reading frames and liver disease progression. Since some of the results were controversial from different laboratories, it remains to be seen whether functional analyses will confirm their role in modifying the course of infection. PMID:24833874

Naturally occurring mutations associated with resistance to HCV NS5B polymerase and NS3 protease inhibitors in treatment-naïve patients with chronic hepatitis C.

PubMed

Costantino, Angela; Spada, Enea; Equestre, Michele; Bruni, Roberto; Tritarelli, Elena; Coppola, Nicola; Sagnelli, Caterina; Sagnelli, Evangelista; Ciccaglione, Anna Rita

2015-11-14

The detection of baseline resistance mutations to new direct-acting antivirals (DAAs) in HCV chronically infected treatment-naïve patients could be important for their management and outcome prevision. In this study, we investigated the presence of mutations, which have been previously reported to be associated with resistance to DAAs in HCV polymerase (NS5B) and HCV protease (NS3) regions, in sera of treatment-naïve patients. HCV RNA from 152 naïve patients (84 % Italian and 16 % immigrants from various countries) infected with different HCV genotypes (21,1a; 21, 1b; 2, 2a; 60, 2c; 22, 3a; 25, 4d and 1, 4k) was evaluated for sequence analysis. Amplification and sequencing of fragments in the NS5B (nt 8256-8640) and NS3 (nt 3420-3960) regions of HCV genome were carried out for 152 and 28 patients, respectively. The polymorphism C316N/H in NS5B region, associated with resistance to sofosbuvir, was detected in 9 of the 21 (43 %) analysed sequences from genotype 1b-infected patients. Naturally occurring mutations V36L, and M175L in the NS3 protease region were observed in 100 % of patients infected with subtype 2c and 4. A relevant proportion of treatment naïve genotype 1b infected patients evaluated in this study harboured N316 polymorphism and might poorly respond to sofosbuvir treatment. As sofosbuvir has been approved for treatment of HCV chronic infection in USA and Europe including Italy, pre-treatment testing for N316 polymorphism on genotype 1b naïve patients should be considered for this drug.

Differential effect of mutational impairment of penicillin-binding proteins 1A and 1B on Escherichia coli strains harboring thermosensitive mutations in the cell division genes ftsA, ftsQ, ftsZ, and pbpB.

PubMed Central

García del Portillo, F; de Pedro, M A

1990-01-01

To study the functional differences between penicillin-binding proteins (PBPs) 1A and 1B, as well as their recently postulated involvement in the septation process (F. García del Portillo, M. A. de Pedro, D. Joseleau-Petit, and R. D'Ari, J. Bacteriol. 171:4217-4221, 1989), a series of isogenic strains with mutations in the genes coding for PBP 1A (ponA) or PBP 1B (ponB) or in the cell division-specific genes ftsA, ftsQ, pbpB, and ftsZ was constructed and used as the start point to produce double mutants combining the ponA or ponB characters with mutations in cell division genes. PBP 1A seemed to be unable to preserve cell integrity by itself, requiring the additional activities of PBP 2, PBP 3, and FtsQ. PBP 1B was apparently endowed with a more versatile biosynthetic potential that permitted a substantial enlargement of PBP 1A-deficient cells when PBP 2 or 3 was inhibited or when FtsQ was inactive. beta-Lactams binding to PBP 2 (mecillinam) or 3 (furazlocillin) caused rapid lysis in a ponB background. The lytic effect of furazlocillin to ponB cell division double mutants was suppressed at the restrictive temperature irrespective of the identity of the mutated cell division gene. These results indicate that PBPs 1A and 1B play distinct roles in cell wall synthesis and support the idea of a relevant involvement of PBP 1B in peptidoglycan synthesis at the time of septation. Images PMID:2211517

Mutations in 3 genes (MKS3, CC2D2A and RPGRIP1L) cause COACH syndrome (Joubert syndrome with congenital hepatic fibrosis)

PubMed Central

Doherty, D; Parisi, M A; Finn, L S; Gunay-Aygun, M; Al-Mateen, M; Bates, D; Clericuzio, C; Demir, H; Dorschner, M; van Essen, A J; Gahl, W A; Gentile, M; Gorden, N T; Hikida, A; Knutzen, D; Özyurek, H; Phelps, I; Rosenthal, P; Verloes, A; Weigand, H; Chance, P F; Dobyns, W B; Glass, I A

2011-01-01

Objective To identify genetic causes of COACH syndrome Background COACH syndrome is a rare autosomal recessive disorder characterised by Cerebellar vermis hypoplasia, Oligophrenia (developmental delay/mental retardation), Ataxia, Coloboma, and Hepatic fibrosis. The vermis hypoplasia falls in a spectrum of mid-hindbrain malformation called the molar tooth sign (MTS), making COACH a Joubert syndrome related disorder (JSRD). Methods In a cohort of 251 families with JSRD, 26 subjects in 23 families met criteria for COACH syndrome, defined as JSRD plus clinically apparent liver disease. Diagnostic criteria for JSRD were clinical findings (intellectual impairment, hypotonia, ataxia) plus supportive brain imaging findings (MTS or cerebellar vermis hypoplasia). MKS3/TMEM67 was sequenced in all subjects for whom DNA was available. In COACH subjects without MKS3 mutations, CC2D2A, RPGRIP1L and CEP290 were also sequenced. Results 19/23 families (83%) with COACH syndrome carried MKS3 mutations, compared to 2/209 (1%) with JSRD but no liver disease. Two other families with COACH carried CC2D2A mutations, one family carried RPGRIP1L mutations, and one lacked mutations in MKS3, CC2D2A, RPGRIP1L and CEP290. Liver biopsies from three subjects, each with mutations in one of the three genes, revealed changes within the congenital hepatic fibrosis/ductal plate malformation spectrum. In JSRD with and without liver disease, MKS3 mutations account for 21/232 families (9%). Conclusions Mutations in MKS3 are responsible for the majority of COACH syndrome, with minor contributions from CC2D2A and RPGRIP1L; therefore, MKS3 should be the first gene tested in patients with JSRD plus liver disease and/or coloboma, followed by CC2D2A and RPGRIP1L. PMID:19574260

Let-7b Regulates Myoblast Proliferation by Inhibiting IGF2BP3 Expression in Dwarf and Normal Chicken

PubMed Central

Lin, Shumao; Luo, Wen; Ye, Yaqiong; Bekele, Endashaw J.; Nie, Qinghua; Li, Yugu; Zhang, Xiquan

2017-01-01

The sex-linked dwarf chicken is caused by the mutation of growth hormone receptor (GHR) gene and characterized by shorter shanks, lower body weight, smaller muscle fiber diameter and fewer muscle fiber number. However, the precise regulatory pathways that lead to the inhibition of skeletal muscle growth in dwarf chickens still remain unclear. Here we found a let-7b mediated pathway might play important role in the regulation of dwarf chicken skeletal muscle growth. Let-7b has higher expression in the skeletal muscle of dwarf chicken than in normal chicken, and the expression of insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), which is a translational activator of IGF2, showed opposite expression trend to let-7b. In vitro cellular assays validated that let-7b directly inhibits IGF2BP3 expression through binding to its 3′UTR region, and the protein level but not mRNA level of IGF2 would be reduced in let-7b overexpressed chicken myoblast. Let-7b can inhibit cell proliferation and induce cell cycle arrest in chicken myoblast through let-7b-IGF2BP3-IGF2 signaling pathway. Additionally, let-7b can also regulate skeletal muscle growth through let-7b-GHR-GHR downstream genes pathway, but this pathway is non-existent in dwarf chicken because of the deletion mutation of GHR 3′UTR. Notably, as the loss binding site of GHR for let-7b, let-7b has enhanced its binding and inhibition on IGF2BP3 in dwarf myoblast, suggesting that the miRNA can balance its inhibiting effect through dynamic regulate its binding to target genes. Collectively, these results not only indicate that let-7b can inhibit skeletal muscle growth through let-7b-IGF2BP3-IGF2 signaling pathway, but also show that let-7b regulates myoblast proliferation by inhibiting IGF2BP3 expression in dwarf and normal chickens. PMID:28736533

Effects of mutations on active site conformation and dynamics of RNA-dependent RNA polymerase from Coxsackievirus B3.

PubMed

Shen, Hujun; Deng, Mingsen; Zhang, Yachao

2017-10-01

Recent crystal structures of RNA-dependent RNA polymerase (3D pol ) from Coxsackievirus B3 (CVB3) revealed that a tyrosine mutation at Phe364 (F364Y) resulted in structures with open active site whereas a hydrophobic mutation at Phe364 (F364A) led to conformations with closed active site. Besides, the crystal structures showed that the F364W mutation had no preference between the open and closed active sites, similar to wild-type. In this paper, we present a molecular dynamics (MD) study on CVB3 3D pol in order to address some important questions raised by experiments. First, MD simulations of F364Y and F364A were carried out to explore how these mutations at Phe364 influence active site dynamics and conformations. Second, MD simulations of wild-type and mutants were performed to discover the connection between active site dynamics and polymerase function. MD simulations reveal that the effect of mutations on active site dynamics is associated with the interaction between the structural motifs A and D in CVB3 3D pol . Interestingly, we discover that the active site state is influenced by the formation of a hydrogen bond between backbone atoms of Ala231 (in motif A) and Ala358 (in motif D), which has never been revealed before. Copyright © 2017 Elsevier Inc. All rights reserved.

Mutation of Chinese Hamster V79 cells and transformation and mutation of mouse fibroblast C3H/10T1/2 clone 8 cells by aflatoxin B1 and four other furocoumarins isolated from two Nigerian medicinal plants.

PubMed

Uwaifo, A O; Billings, P C; Heidelberger, C

1983-03-01

Mutation by aflatoxin B1 (AFB1), imperatorin, marmesin, chalepin, and 8-methoxypsoralen (MOP), with and without black light (BL; long-wavelength ultraviolet light) activation, was determined at the hypoxanthine-guanine phosphoribosyltransferase locus (8-azaguanine resistance) in Chinese hamster V79 cells and at the ouabain locus in mouse C3H/1OT1/2 cells. Transformation by these furocoumarins under the same activation conditions was also investigated in C3H/1OT1/2 cells. In V79 cells, AFB1 induced a 4-fold maximum mutation frequency over controls under BL activation at a concentration of 5 micrograms/ml; marmesin induced a 2-fold increased mutation frequency at 1.5 micrograms/ml; MOP induced a 19-fold increase at 10 micrograms/ml; chalepin induced a 3-fold increase at 5 micrograms/ml; and imperatorin induced a 20-fold increase at 10 micrograms/ml. Essentially no mutation was observed at the ouabain-resistant (Ouar) locus in C3H/1OT1/2 cells with any of these compounds. In the transformation assays, type II and type III foci were observed at a 1-microgram/ml addition of AFB1 with or without BL activation; while with MOP and imperatorin, these types of foci were observed only with BL activation. Marmesin, although relatively more cytotoxic than the other furocoumarins studied, with a 50% lethal dose of less than 0.5 micrograms/ml, was not as mutagenic or potentially carcinogenic as were AFB1, imperatorin, or MOP with BL activation. These furocoumarins are considered to be involved in the etiology of the high incidence of skin cancer in Nigeria. Our experiments reinforce that concept and suggest that exposure to these furocoumarins may constitute a real carcinogenic hazard.

Mutations in cell elongation genes mreB, mrdA and mrdB suppress the shape defect of RodZ-deficient cells.

PubMed

Shiomi, Daisuke; Toyoda, Atsushi; Aizu, Tomoyuki; Ejima, Fumio; Fujiyama, Asao; Shini, Tadasu; Kohara, Yuji; Niki, Hironori

2013-03-01

RodZ interacts with MreB and both factors are required to maintain the rod shape of Escherichia coli. The assembly of MreB into filaments regulates the subcellular arrangement of a group of enzymes that synthesizes the peptidoglycan (PG) layer. However, it is still unknown how polymerization of MreB determines the rod shape of bacterial cells. Regulatory factor(s) are likely to be involved in controlling the function and dynamics of MreB. We isolated suppressor mutations to partially recover the rod shape in rodZ deletion mutants and found that some of the suppressor mutations occurred in mreB. All of the mreB mutations were in or in the vicinity of domain IA of MreB. Those mreB mutations changed the property of MreB filaments in vivo. In addition, suppressor mutations were found in the periplasmic regions in PBP2 and RodA, encoded by mrdA and mrdB genes. Similar to MreB and RodZ, PBP2 and RodA are pivotal to the cell wall elongation process. Thus, we found that mutations in domain IA of MreB and in the periplasmic domain of PBP2 and RodA can restore growth and rod shape to ΔrodZ cells, possibly by changing the requirements of MreB in the process. © 2013 Blackwell Publishing Ltd.

Mutations in cell elongation genes mreB, mrdA and mrdB suppress the shape defect of RodZ-deficient cells

PubMed Central

Shiomi, Daisuke; Toyoda, Atsushi; Aizu, Tomoyuki; Ejima, Fumio; Fujiyama, Asao; Shini, Tadasu; Kohara, Yuji; Niki, Hironori

2013-01-01

RodZ interacts with MreB and both factors are required to maintain the rod shape of Escherichia coli. The assembly of MreB into filaments regulates the subcellular arrangement of a group of enzymes that synthesizes the peptidoglycan (PG) layer. However, it is still unknown how polymerization of MreB determines the rod shape of bacterial cells. Regulatory factor(s) are likely to be involved in controlling the function and dynamics of MreB. We isolated suppressor mutations to partially recover the rod shape in rodZ deletion mutants and found that some of the suppressor mutations occurred in mreB. All of the mreB mutations were in or in the vicinity of domain IA of MreB. Those mreB mutations changed the property of MreB filaments in vivo. In addition, suppressor mutations were found in the periplasmic regions in PBP2 and RodA, encoded by mrdA and mrdB genes. Similar to MreB and RodZ, PBP2 and RodA are pivotal to the cell wall elongation process. Thus, we found that mutations in domain IA of MreB and in the periplasmic domain of PBP2 and RodA can restore growth and rod shape to ΔrodZ cells, possibly by changing the requirements of MreB in the process. PMID:23301723

The endosomal protein CHARGED MULTIVESICULAR BODY PROTEIN1 regulates the autophagic turnover of plastids in Arabidopsis.

PubMed

Spitzer, Christoph; Li, Faqiang; Buono, Rafael; Roschzttardtz, Hannetz; Chung, Taijoon; Zhang, Min; Osteryoung, Katherine W; Vierstra, Richard D; Otegui, Marisa S

2015-02-01

Endosomal Sorting Complex Required for Transport (ESCRT)-III proteins mediate membrane remodeling and the release of endosomal intraluminal vesicles into multivesicular bodies. Here, we show that the ESCRT-III subunit paralogs CHARGED MULTIVESICULAR BODY PROTEIN1 (CHMP1A) and CHMP1B are required for autophagic degradation of plastid proteins in Arabidopsis thaliana. Similar to autophagy mutants, chmp1a chmp1b (chmp1) plants hyperaccumulated plastid components, including proteins involved in plastid division. The autophagy machinery directed the release of bodies containing plastid material into the cytoplasm, whereas CHMP1A and B were required for delivery of these bodies to the vacuole. Autophagy was upregulated in chmp1 as indicated by an increase in vacuolar green fluorescent protein (GFP) cleavage from the autophagic reporter GFP-ATG8. However, autophagic degradation of the stromal cargo RECA-GFP was drastically reduced in the chmp1 plants upon starvation, suggesting that CHMP1 mediates the efficient delivery of autophagic plastid cargo to the vacuole. Consistent with the compromised degradation of plastid proteins, chmp1 plastids show severe morphological defects and aberrant division. We propose that CHMP1 plays a direct role in the autophagic turnover of plastid constituents. © 2015 American Society of Plant Biologists. All rights reserved.

Missense mutation of the cholecystokinin B receptor gene: Lack of association with panic disorder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kato, Tadafumi; Wang, Zhe Wu; Crowe, R.R.

1996-07-26

Cholecystokinin tetrapeptide (CCK{sub 4}) is known to induce panic attacks in patients with panic disorder at a lower dose than in normal controls. Therefore, the cholecystokinin B (CCK{sub B}) receptor gene is a candidate gene for panic disorder. We searched for mutations in the CCK{sub B} gene in 22 probands of panic disorder pedigrees, using single-strand conformation polymorphism (SSCP) analysis. Two polymorphisms were detected. A polymorphism in an intron (2491 C{yields}A) between exons 4 and 5 was observed in 10 of 22 probands. A missense mutation in the extracellular loop of exon 2 (1550 G{yields}A, Val{sup 125}{yields}Ile) was found inmore » only one proband. This mutation was also examined in additional 34 unrelated patients with panic disorder and 112 controls. The prevalence rate of this mutation was 8.8% in patients with panic disorder (3/34) and 4.4% in controls (5/112). The mutation did not segregate with panic disorder in two families where this could be tested. These results suggest no pathophysiological significance of this mutation in panic disorder. 21 refs., 4 figs., 1 tab.« less

Als and Ftd: Insights into the disease mechanisms and therapeutic targets.

PubMed

Liscic, Rajka M

2017-12-15

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are neurodegenerative disorders, related by signs of deteriorating motor and cognitive functions, and short survival. The causes are still largely unknown and no effective treatment currently exists. It has been shown that FTLD may coexist with ALS. The overlap between ALS and frontotemporal dementia (FTD), the clinical syndrome associated with FTLD, occurs at clinical, genetic, and pathological levels. The hallmark proteins of the pathognomonic inclusions are SOD-1, TDP-43 or FUS, rarely the disease is caused by mutations in the respective genes. Frontotemporal lobar degenerations (FTLD) is genetically, neuropathologically and clinically heterogeneous and may present with behavioural, language and occasionally motor disorder, respectively. Almost all cases of ALS, as well as tau-negative FTLD share a common neuropathology, neuronal and glial inclusion bodies containing abnormal TDP-43 protein, collectively called TDP-43 proteinopathy. Recent discoveries in genetics (e.g. C9orf72 hexanucleotide expansion) and the subsequent neuropathological characterization have revealed remarkable overlap between ALS and FTLD-TDP indicating common pathways in pathogenesis. For ALS, an anti-glutamate agent riluzole may be offered to slow disease progression (Level A), and a promising molecule, arimoclomol, is currently in clinical trials. Other compounds, however, are being trailed and some have shown encouraging results. As new therapeutic approaches continue to emerge by targeting SOD1, TDP-43, or GRN, we present some advances that are being made in our understanding of the molecular mechanisms of these diseases, which together with gene and stem cell therapies may translate into new treatment options. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Exercise on Progranulin Levels and Gliosis in Progranulin-Insufficient Mice1,2,3

PubMed Central

Arrant, Andrew E.; Patel, Aashka R.

2015-01-01

Abstract Loss-of-function mutations in progranulin (GRN) are one of the most common genetic causes of frontotemporal dementia (FTD), a progressive, fatal neurodegenerative disorder with no available disease-modifying treatments. Through haploinsufficiency, these mutations reduce levels of progranulin, a protein that has neurotrophic and anti-inflammatory effects. Increasing progranulin expression from the intact allele is therefore a potential approach for treating individuals with GRN mutations. Based on the well-known effects of physical exercise on other neurotrophic factors, we hypothesized that exercise might increase brain progranulin levels. We tested this hypothesis in progranulin heterozygous (Grn+/−) mice, which model progranulin haploinsufficiency. We housed wild-type and progranulin-insufficient mice in standard cages or cages with exercise wheels for 4 or 7.5 weeks, and then measured brain and plasma progranulin levels. Although exercise modestly increased progranulin in very young (2-month-old) wild-type mice, this effect was limited to the hippocampus. Exercise did not increase brain progranulin mRNA or protein in multiple regions, nor did it increase plasma progranulin, in 4- to 8-month-old wild-type or Grn+/− mice, across multiple experiments and under conditions that increased hippocampal BDNF and neurogenesis. Grn−/−mice were included in the study to test for progranulin-independent benefits of exercise on gliosis. Exercise attenuated cortical microgliosis in 8-month-old Grn−/−mice, consistent with a progranulin-independent, anti-inflammatory effect of exercise. These results suggest that exercise may have some modest, nonspecific benefits for FTD patients with progranulin mutations, but do not support exercise as a strategy to raise progranulin levels. PMID:26361634

ULK3 regulates cytokinetic abscission by phosphorylating ESCRT-III proteins

DOE PAGES

Caballe, Anna; Wenzel, Dawn M.; Agromayor, Monica; ...

2015-05-26

The endosomal sorting complexes required for transport (ESCRT) machinery mediates the physical separation between daughter cells during cytokinetic abscission. This process is regulated by the abscission checkpoint, a genome protection mechanism that relies on Aurora B and the ESCRT-III subunit CHMP4C to delay abscission in response to chromosome missegregation. In this study, we show that Unc-51-like kinase 3 (ULK3) phosphorylates and binds ESCRT-III subunits via tandem MIT domains, and thereby, delays abscission in response to lagging chromosomes, nuclear pore defects, and tension forces at the midbody. Our structural and biochemical studies reveal an unusually tight interaction between ULK3 and IST1,more » an ESCRT-III subunit required for abscission. We also demonstrate that IST1 phosphorylation by ULK3 is an essential signal required to sustain the abscission checkpoint and that ULK3 and CHMP4C are functionally linked components of the timer that controls abscission in multiple physiological situations.« less

ULK3 regulates cytokinetic abscission by phosphorylating ESCRT-III proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caballe, Anna; Wenzel, Dawn M.; Agromayor, Monica

The endosomal sorting complexes required for transport (ESCRT) machinery mediates the physical separation between daughter cells during cytokinetic abscission. This process is regulated by the abscission checkpoint, a genome protection mechanism that relies on Aurora B and the ESCRT-III subunit CHMP4C to delay abscission in response to chromosome missegregation. In this study, we show that Unc-51-like kinase 3 (ULK3) phosphorylates and binds ESCRT-III subunits via tandem MIT domains, and thereby, delays abscission in response to lagging chromosomes, nuclear pore defects, and tension forces at the midbody. Our structural and biochemical studies reveal an unusually tight interaction between ULK3 and IST1,more » an ESCRT-III subunit required for abscission. We also demonstrate that IST1 phosphorylation by ULK3 is an essential signal required to sustain the abscission checkpoint and that ULK3 and CHMP4C are functionally linked components of the timer that controls abscission in multiple physiological situations.« less

Mutations in STX1B, encoding a presynaptic protein, cause fever-associated epilepsy syndromes.

PubMed

Schubert, Julian; Siekierska, Aleksandra; Langlois, Mélanie; May, Patrick; Huneau, Clément; Becker, Felicitas; Muhle, Hiltrud; Suls, Arvid; Lemke, Johannes R; de Kovel, Carolien G F; Thiele, Holger; Konrad, Kathryn; Kawalia, Amit; Toliat, Mohammad R; Sander, Thomas; Rüschendorf, Franz; Caliebe, Almuth; Nagel, Inga; Kohl, Bernard; Kecskés, Angela; Jacmin, Maxime; Hardies, Katia; Weckhuysen, Sarah; Riesch, Erik; Dorn, Thomas; Brilstra, Eva H; Baulac, Stephanie; Møller, Rikke S; Hjalgrim, Helle; Koeleman, Bobby P C; Jurkat-Rott, Karin; Lehman-Horn, Frank; Roach, Jared C; Glusman, Gustavo; Hood, Leroy; Galas, David J; Martin, Benoit; de Witte, Peter A M; Biskup, Saskia; De Jonghe, Peter; Helbig, Ingo; Balling, Rudi; Nürnberg, Peter; Crawford, Alexander D; Esguerra, Camila V; Weber, Yvonne G; Lerche, Holger

2014-12-01

Febrile seizures affect 2-4% of all children and have a strong genetic component. Recurrent mutations in three main genes (SCN1A, SCN1B and GABRG2) have been identified that cause febrile seizures with or without epilepsy. Here we report the identification of mutations in STX1B, encoding syntaxin-1B, that are associated with both febrile seizures and epilepsy. Whole-exome sequencing in independent large pedigrees identified cosegregating STX1B mutations predicted to cause an early truncation or an in-frame insertion or deletion. Three additional nonsense or missense mutations and a de novo microdeletion encompassing STX1B were then identified in 449 familial or sporadic cases. Video and local field potential analyses of zebrafish larvae with antisense knockdown of stx1b showed seizure-like behavior and epileptiform discharges that were highly sensitive to increased temperature. Wild-type human syntaxin-1B but not a mutated protein rescued the effects of stx1b knockdown in zebrafish. Our results thus implicate STX1B and the presynaptic release machinery in fever-associated epilepsy syndromes.

Genetic and Pathological Assessment of hnRNPA1, hnRNPA2/B1, and hnRNPA3 in Familial and Sporadic Amyotrophic Lateral Sclerosis.

PubMed

Fifita, Jennifer A; Zhang, Katharine Y; Galper, Jasmin; Williams, Kelly L; McCann, Emily P; Hogan, Alison L; Saunders, Neil; Bauer, Denis; Tarr, Ingrid S; Pamphlett, Roger; Nicholson, Garth A; Rowe, Dominic; Yang, Shu; Blair, Ian P

2017-01-01

Mutations in the genes encoding the heterogeneous nuclear ribonucleoproteins hnRNPA1 and hnRNPA2/B1 have been reported in a multisystem proteinopathy that includes amyotrophic lateral sclerosis (ALS) and inclusion body myopathy associated with Paget disease of the bone and frontotemporal dementia. Mutations were also described in the prion-like domain of hnRNPA1 in patients with classic ALS. Another hnRNP protein, hnRNPA3, has been found to be associated with the ALS/frontotemporal dementia protein C9orf72. To further assess their role in ALS, we examined these hnRNPs in spinal cord tissue from sporadic (SALS) and familial ALS (FALS) patients, including C9orf72 repeat expansion-positive patients, and controls. We also sought to determine the prevalence of HNRNPA1, HNRNPA2B1, and HNRNPA3 mutations in Australian ALS patients. Immunostaining was used to assess hnRNPs in ALS patient spinal cords. Mutation analysis of the HNRNPA1, HNRNPA2B1, and HNRNPA3 genes was performed in FALS and of their prion-like domains in SALS patients. Immunostaining of spinal motor neurons of ALS patients with the C9orf72 repeat expansion showed significant mislocalisation of hnRNPA3, and no differences in hnRNPA1 or A2/B1 localisation, compared to controls. No novel or known mutations were identified in HNRNPA1, HNRNPA2B1, or HNRNPA3 in Australian ALS patients. hnRNPA3 pathology was identified in motor neurons of ALS patients with C9orf72 repeat expansions, implicating hnRNPA3 in the pathogenesis of C9orf72-linked ALS. hnRNPA3 warrants further investigation into the pathogenesis of ALS linked to C9orf72. This study also determined that HNRNP mutations are not a common cause of FALS and SALS in Australia. © 2017 S. Karger AG, Basel.

Mutational spectrum of myeloid malignancies with inv(3)/t(3;3) reveals a predominant involvement of RAS/RTK signaling pathways

PubMed Central

Gröschel, Stefan; Sanders, Mathijs A.; Hoogenboezem, Remco; Zeilemaker, Annelieke; Havermans, Marije; Erpelinck, Claudia; Bindels, Eric M. J.; Beverloo, H. Berna; Döhner, Hartmut; Löwenberg, Bob; Döhner, Konstanze; Delwel, Ruud

2015-01-01

Myeloid malignancies bearing chromosomal inv(3)/t(3;3) abnormalities are among the most therapy-resistant leukemias. Deregulated expression of EVI1 is the molecular hallmark of this disease; however, the genome-wide spectrum of cooperating mutations in this disease subset has not been systematically elucidated. Here, we show that 98% of inv(3)/t(3;3) myeloid malignancies harbor mutations in genes activating RAS/receptor tyrosine kinase (RTK) signaling pathways. In addition, hemizygous mutations in GATA2, as well as heterozygous alterations in RUNX1, SF3B1, and genes encoding epigenetic modifiers, frequently co-occur with the inv(3)/t(3;3) aberration. Notably, neither mutational patterns nor gene expression profiles differ across inv(3)/t(3;3) acute myeloid leukemia, chronic myeloid leukemia, and myelodysplastic syndrome cases, suggesting recognition of inv(3)/t(3;3) myeloid malignancies as a single disease entity irrespective of blast count. The high incidence of activating RAS/RTK signaling mutations may provide a target for a rational treatment strategy in this high-risk patient group. PMID:25381062

Concomitance of oncogenic HPV types, CHEK2 gene mutations, and CYP1B1 gene polymorphism as an increased risk factor for malignancy.

PubMed

Banaszkiewicz, Monika; Constantinou, Maria; Pietrusiński, Michał; Kępczyński, Lukasz; Jędrzejczyk, Adam; Rożniecki, Marek; Marks, Piotr; Kałużewski, Bogdan

2013-01-01

Urinary bladder carcinoma ranks the fourth position in malignancy incidence rates in men (6.1%) and the 17th position in women (1.6%). In general, neoplastic diseases should be approached from two perspectives: prevention with implementation of prophylactic measures and early diagnostics. Prophylactics is possible in the preclinical phase of neoplasm, being both justified and plausible in patients from high-risk groups. Thus, it is particularly important to select such groups, not only by referring to environmental carcinogenic factors (occupational and extra-occupational) but also from genetic predisposition, which may be conductive for neoplasm formation. The mutations / polymorphisms of CHEK2 and CYP1B1 genes predispose to neoplasm via multiorgan mechanisms, while the human papilloma virus (HPV) may participate in the neoplastic transformation as an environmental factor. 131 patients with diagnosed urinary bladder cancer were qualified to the study. Mutations/polymorphisms of CHEK2 (IVS2 + 1G > A gene, 1100delC, del5395, I157T) and CYP1B1- 355T/T were identified by the PCR in DNA isolated directly from the tumor and from peripheral blood. The ELISA test was used for the studies of 37 HPV genotypes in DNA, isolated tumour tissue. 11 mutations of CHEK2 gene were found, 355T/T polymorphism if CYP1B1 gene occurred in 18 patients (12.9%). Oncogenic HPV was found in 36 (29.3%), out of 123 examined patients. The concomitance of CHEK2 gene mutations or 355T/T polymorphism of CYP1B1 gene and the presence of oncogenic HPV types statistically significantly correlates with histological malignancy grades of urinary bladder carcinoma.

Cryopyrin-associated Periodic Syndrome Caused by a Myeloid-Restricted Somatic NLRP3 Mutation

PubMed Central

Zhou, Qing; Aksentijevich, Ivona; Wood, Geryl M.; Walts, Avram D.; Hoffmann, Patrycja; Remmers, Elaine F.; Kastner, Daniel L.; Ombrello, Amanda K.

2015-01-01

Objective To identify the cause of disease in an adult patient presenting with recent onset fevers, chills, urticaria, fatigue, and profound myalgia, who was negative for cryopyrin-associated periodic syndrome (CAPS) NLRP3 mutations by conventional Sanger DNA sequencing. Methods We performed whole-exome sequencing and targeted deep sequencing using DNA from the patient’s whole blood to identify a possible NLRP3 somatic mutation. We then screened for this mutation in subcloned NLRP3 amplicons from fibroblasts, buccal cells, granulocytes, negatively-selected monocytes, and T and B lymphocytes and further confirmed the somatic mutation by targeted sequencing of exon 3. Results We identified a previously reported CAPS-associated mutation, p.Tyr570Cys, with a mutant allele frequency of 15% based on exome data. Targeted sequencing and subcloning of NLRP3 amplicons confirmed the presence of the somatic mutation in whole blood at a ratio similar to the exome data. The mutant allele frequency was in the range of 13.3%–16.8% in monocytes and 15.2%–18% in granulocytes; Notably, this mutation was either absent or present at a very low frequency in B and T lymphocytes, buccal cells, and in the patient’s cultured fibroblasts. Conclusion These data document the possibility of myeloid-restricted somatic mosaicism in the pathogenesis of CAPS, underscoring the emerging role of massively-parallel sequencing in clinical diagnosis. PMID:25988971

A Missense Mutation in PPP1R15B Causes a Syndrome Including Diabetes, Short Stature, and Microcephaly

PubMed Central

Abdulkarim, Baroj; Igoillo-Esteve, Mariana; Daures, Mathilde; Romero, Sophie; Philippi, Anne; Senée, Valérie; Lopes, Miguel; Cunha, Daniel A.; Harding, Heather P.; Derbois, Céline; Bendelac, Nathalie; Hattersley, Andrew T.; Eizirik, Décio L.; Ron, David

2015-01-01

Dysregulated endoplasmic reticulum stress and phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) are associated with pancreatic β-cell failure and diabetes. Here, we report the first homozygous mutation in the PPP1R15B gene (also known as constitutive repressor of eIF2α phosphorylation [CReP]) encoding the regulatory subunit of an eIF2α-specific phosphatase in two siblings affected by a novel syndrome of diabetes of youth with short stature, intellectual disability, and microcephaly. The R658C mutation in PPP1R15B affects a conserved amino acid within the domain important for protein phosphatase 1 (PP1) binding. The R658C mutation decreases PP1 binding and eIF2α dephosphorylation and results in β-cell apoptosis. Our findings support the concept that dysregulated eIF2α phosphorylation, whether decreased by mutation of the kinase (EIF2AK3) in Wolcott-Rallison syndrome or increased by mutation of the phosphatase (PPP1R15B), is deleterious to β-cells and other secretory tissues, resulting in diabetes associated with multisystem abnormalities. PMID:26159176

[A study of PDE6B gene mutation and phenotype in Chinese cases with retinitis pigmentosa].

PubMed

Cui, Yun; Zhao, Kan-xing; Wang, Li; Wang, Qing; Zhang, Wei; Chen, Wei-ying; Wang, Li-ming

2003-01-01

To identify the mutation spectrum of phosphodiesterase beta subunit (PDE6B) gene, the incidence in Chinese patients with retinitis pigmentosa (RP) and their clinical phenotypic characteristics. Screening of mutations within PDE6B gene was performed using polymerase chain reaction-heteroduplex-single strand conformation polymorphism (PCR-SSCP) and DNA sequence in 35 autosomal recessive (AR) RP and 55 sporadic RP cases. The phenotypes of the patients with the gene mutation were examined and analyzed. Novel complex heterozygous variants of PDE6B gene in a sporadic case, a T to C transversion in codon 323 resulting in the substitution of Gly by Ser and 2 base pairs (bp: G and T) insert between the 27th-28th bp upstream of the 5'-end of exon 10 were both present in a same isolate RP. But they are not found in 100 unrelated healthy individuals. Ocular findings showed diffuse pigmentary retinal degeneration in the midperipheral and peripheral fundi, optic atrophy and vessel attenuation. Multi-focal ERG indicated that the rod function was more severely deteriorated. A mutation was found in a case with RP in a ARRP family, a G to A transversion at 19th base upstream 5'-end of exon 11 (within intron 10) of PDE6B gene. A sporadic RP carried a sequence variant of PDE6B gene, a G to C transition, at the 15th base adjacent to the 3'-end of exon l8. In another isolate case with RP was found 2 bp (GT) insert between 31st and 32nd base upstream 5'-end of exon 4 (in intron 3) of PDE6B gene. There are novel complex heterozygous mutations of PDE6B gene responsible for a sporadic RP patient in China. This gene mutation associated with rod deterioration and RP. Several DNA variants were found in introns of PDE6B gene in national population.

Polyalanine expansion and frameshift mutations of the paired-like homeobox gene PHOX2B in congenital central hypoventilation syndrome.

PubMed

Amiel, Jeanne; Laudier, Béatrice; Attié-Bitach, Tania; Trang, Ha; de Pontual, Loïc; Gener, Blanca; Trochet, Delphine; Etchevers, Heather; Ray, Pierre; Simonneau, Michel; Vekemans, Michel; Munnich, Arnold; Gaultier, Claude; Lyonnet, Stanislas

2003-04-01

Congenital central hypoventilation syndrome (CCHS or Ondine's curse; OMIM 209880) is a life-threatening disorder involving an impaired ventilatory response to hypercarbia and hypoxemia. This core phenotype is associated with lower-penetrance anomalies of the autonomic nervous system (ANS) including Hirschsprung disease and tumors of neural-crest derivatives such as ganglioneuromas and neuroblastomas. In mice, the development of ANS reflex circuits is dependent on the paired-like homeobox gene Phox2b. Thus, we regarded its human ortholog, PHOX2B, as a candidate gene in CCHS. We found heterozygous de novo mutations in PHOX2B in 18 of 29 individuals with CCHS. Most mutations consisted of 5-9 alanine expansions within a 20-residue polyalanine tract probably resulting from non-homologous recombination. We show that PHOX2B is expressed in both the central and the peripheral ANS during human embryonic development. Our data support an essential role of PHOX2B in the normal patterning of the autonomous ventilation system and, more generally, of the ANS in humans.

A homozygous mutation in the endothelin-3 gene associated with a combined Waardenburg type 2 and Hirschsprung phenotype (Shah-Waardenburg syndrome).

PubMed

Hofstra, R M; Osinga, J; Tan-Sindhunata, G; Wu, Y; Kamsteeg, E J; Stulp, R P; van Ravenswaaij-Arts, C; Majoor-Krakauer, D; Angrist, M; Chakravarti, A; Meijers, C; Buys, C H

1996-04-01

Hirschsprung disease (HSCR) or colonic aganglionosis is a congenital disorder characterized by an absence of intramural ganglia along variable lengths of the colon resulting in intestinal obstruction. The incidence of HSCR is 1 in 5,000 live births. Mutations in the RET gene, which codes for a receptor tyrosine kinase, and in EDNRB which codes for the endothelin-B receptor, have been shown to be associated with HSCR in humans. The lethal-spotted mouse which has pigment abnormalities, but also colonic aganglionosis, carries a mutation in the gene coding for endothelin 3 (Edn3), the ligand for the receptor protein encoded by EDNRB. Here, we describe a mutation of the human gene for endothelin 3 (EDN3), homozygously present in a patient with a combined Waardenburg syndrome type 2 (WS2) and HSCR phenotype (Shah-Waardenburg syndrome). The mutation, Cys159Phe, in exon 3 in the ET-3 like domain of EDN3, presumably affects the proteolytic processing of the preproendothelin to the mature peptide EDN3. The patient's parents were first cousins. A previous child in this family had been diagnosed with a similar combination of HSCR, depigmentation and deafness. Depigmentation and deafness were present in other relatives. Moreover, we present a further indication for the involvement of EDNRB in HSCR by reporting a novel mutation detected in one of 40 unselected HSCR patients.

Current Advances and Limitations in Modeling ALS/FTD in a Dish Using Induced Pluripotent Stem Cells

PubMed Central

Guo, Wenting; Fumagalli, Laura; Prior, Robert; Van Den Bosch, Ludo

2017-01-01

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two age-dependent multifactorial neurodegenerative disorders, which are typically characterized by the selective death of motor neurons and cerebral cortex neurons, respectively. These two diseases share many clinical, genetic and pathological aspects. During the past decade, cell reprogramming technologies enabled researchers to generate human induced pluripotent stem cells (iPSCs) from somatic cells. This resulted in the unique opportunity to obtain specific neuronal and non-neuronal cell types from patients which could be used for basic research. Moreover, these in vitro models can mimic not only the familial forms of ALS/FTD, but also sporadic cases without known genetic cause. At present, there have been extensive technical advances in the generation of iPSCs, as well as in the differentiation procedures to obtain iPSC-derived motor neurons, cortical neurons and non-neuronal cells. The major challenge at this moment is to determine whether these iPSC-derived cells show relevant phenotypes that recapitulate complex diseases. In this review, we will summarize the work related to iPSC models of ALS and FTD. In addition, we will discuss potential drawbacks and solutions for establishing more trustworthy iPSC models for both ALS and FTD. PMID:29326542

Elevated expression of activated forms of Neu/ErbB-2 and ErbB-3 are involved in the induction of mammary tumors in transgenic mice: implications for human breast cancer.

PubMed Central

Siegel, P M; Ryan, E D; Cardiff, R D; Muller, W J

1999-01-01

To assess the importance of Neu activation during mammary tumorigenesis, altered receptors harboring in-frame deletions within the extracellular domain were expressed in transgenic mice. Females from several independent lines develop multiple mammary tumors that frequently metastasize to the lung. Tumor progression in these strains was associated with elevated levels of tyrosine-phosphorylated Neu and ErbB-3. Consistent with these observations, a survey of primary human breast tumors revealed frequent co-expression of both erbB-2 and erbB-3 transcripts. The ability of altered Neu receptors to induce mammary tumorigenesis in transgenic mice prompted us to examine whether similar mutations occurred in ErbB-2 during human breast cancer progression. Interestingly, an alternatively spliced form of erbB-2, closely resembling spontaneous activated forms of neu, was detected in human breast tumors. The ErbB-2 receptor encoded by this novel transcript harbors an in-frame deletion of 16 amino acids in the extracellular domain and can transform Rat-1 fibroblasts. Together, these observations argue that co-expression of ErbB-2 and ErbB-3 may play a critical role in the induction of human breast tumors, and raise the possibility that activating mutations in the ErbB-2 receptor may also contribute to this process. PMID:10205169

Effect of the achondroplasia mutation on FGFR3 dimerization and FGFR3 structural response to fgf1 and fgf2: A quantitative FRET study in osmotically derived plasma membrane vesicles.

PubMed

Sarabipour, Sarvenaz; Hristova, Kalina

2016-07-01

The G380R mutation in the transmembrane domain of FGFR3 is a germline mutation responsible for most cases of Achondroplasia, a common form of human dwarfism. Here we use quantitative Fӧster Resonance Energy Transfer (FRET) and osmotically derived plasma membrane vesicles to study the effect of the achondroplasia mutation on the early stages of FGFR3 signaling in response to the ligands fgf1 and fgf2. Using a methodology that allows us to capture structural changes on the cytoplasmic side of the membrane in response to ligand binding to the extracellular domain of FGFR3, we observe no measurable effects of the G380R mutation on FGFR3 ligand-bound dimer configurations. Instead, the most notable effect of the achondroplasia mutation is increased propensity for FGFR3 dimerization in the absence of ligand. This work reveals new information about the molecular events that underlie the achondroplasia phenotype, and highlights differences in FGFR3 activation due to different single amino-acid pathogenic mutations. Copyright © 2016 Elsevier B.V. All rights reserved.

Phenotypic spectrum of POLR3B mutations: isolated hypogonadotropic hypogonadism without neurological or dental anomalies.

PubMed

Richards, Mary R; Plummer, Lacey; Chan, Yee-Ming; Lippincott, Margaret F; Quinton, Richard; Kumanov, Philip; Seminara, Stephanie B

2017-01-01

A constellation of neurodegenerative disorders exists (Gordon Holmes syndrome, 4H leucodystrophy, Boucher-Neuhauser syndrome) in which patients suffer from both neurological disease (typically manifested by ataxia) and reproductive failure (idiopathic hypogonadotropic hypogonadism (IHH)). POLR3B, which encodes the second largest subunit of RNA polymerase III (pol III), and POLR3A, which forms the pol III catalytic centre, are associated with 4H leucodystrophy. Whole exome sequencing was performed on a large cohort of subjects with IHH (n=565). Detailed neuroendocrine studies were performed in some individuals within this cohort. Four individuals (two of them siblings) were identified with two rare nucleotide variants in POLR3B. On initial evaluation, all subjects were free of neurological disease. One patient underwent treatment with exogenous pulsatile gonadotropin-releasing hormone for 8 weeks which failed to result in normalisation of his sex steroid milieu due to pituitary resistance. These findings suggest that the spectrum of phenotypes resulting from POLR3B mutations is wider than previously believed and that POLR3B can be associated exclusively with disorders characterised by abnormal gonadotropin secretion. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Germinal mosaicism of PAX3 mutation caused Waardenburg syndrome type I.

PubMed

Chen, Kaitian; Zhan, Yuan; Wu, Xuan; Zong, Ling; Jiang, Hongyan

2018-01-01

Waardenburg syndrome mutations are most often recurrent or de novo. The rate of familial recurrence is low and families with several affected children are extremely rare. In this study, we aimed to clarify the underlying hereditary cause of Waardenburg syndrome type I in two siblings in a Chinese family, with a mother affected by prelingual mild hearing loss and a father who was negative for clinical symptoms of Waardenburg syndrome and had a normal hearing threshold. Complete characteristic features of the family members were recorded and genetic sequencing and parent-child relationship analyses were performed. The two probands were found to share double mutations in the PAX3/GJB2 genes that caused concurrent hearing loss in Waardenburg syndrome type I. Their mother carried the GJB2 c.109G > A homozygous mutation; however, neither the novel PAX3 c.592delG mutation, nor the Waardenburg syndrome phenotype, was observed in either parent. These previously unreported digenic mutations in PAX3/GJB2 resulted in deafness associated with Waardenburg syndrome type I in this family. To our knowledge, this is the first report describing germinal mosaicism in Waardenburg syndrome. This concept is important because it complicates genetic counseling of this family regarding the risk of recurrence of the mutations in subsequent pregnancies. Copyright © 2017 Elsevier B.V. All rights reserved.

Oncologic Phenotype of Peripheral Neuroblastic Tumors Associated With PHOX2B Non-Polyalanine Repeat Expansion Mutations.

PubMed

Heide, Solveig; Masliah-Planchon, Julien; Isidor, Bertrand; Guimier, Anne; Bodet, Damien; Coze, Carole; Deville, Anne; Thebault, Estelle; Pasquier, Corinne Jeanne; Cassagnau, Elisabeth; Pierron, Gaelle; Clément, Nathalie; Schleiermacher, Gudrun; Amiel, Jeanne; Delattre, Olivier; Peuchmaur, Michel; Bourdeaut, Franck

2016-01-01

Germline non-polyalanine repeat expansion mutations in PHOX2B (PHOX2B NPARM) predispose to peripheral neuroblastic tumors (PNT), frequently in association with other neurocristopathies: Hirschsprung disease (HSCR) or congenital central hypoventilation syndrome (CCHS). Although PHOX2B polyalanine repeat expansions predispose to a low incidence of benign PNTs, the oncologic phenotype associated with PHOX2B NPARM is still not known in detail. We analyzed prognostic factors, treatment toxicity, and outcome of patients with PNT and PHOX2B NPARM. Thirteen patients were identified, six of whom also had CCHS and/or HSCR, one also had late-onset hypoventilation with hypothalamic dysfunction (LO-CHS/HD), and six had no other neurocristopathy. Four tumours were "poorly differentiated," and nine were differentiated, including five ganglioneuromas, three ganglioneuroblastomas, and one differentiating neuroblastoma, hence illustrating that PHOX2B NPARM are predominantly associated with differentiating tumors. Nevertheless, three patients had stage 4 and one patient had stage 3 disease. Segmental chromosomal alterations, correlating with poor prognosis, were found in all the six tumors analyzed by array-comparative genomic hybridization. One patient died of tumor progression, one is on palliative care, one died of hypoventilation, and 10 patients are still alive, with median follow-up of 5 years. Based on histological phenotype, our series suggests that heterozygous PHOX2B NPARM do not fully preclude ganglion cell differentiation in tumors. However, this tumor predisposition syndrome may also be associated with poorly differentiated tumors with unfavorable genomic profiles and clinically aggressive behaviors. The intrafamilial variability and the unpredictable tumor prognosis should be considered in genetic counseling. © 2015 Wiley Periodicals, Inc.

U2AF1 mutations alter splice site recognition in hematological malignancies.

PubMed

Ilagan, Janine O; Ramakrishnan, Aravind; Hayes, Brian; Murphy, Michele E; Zebari, Ahmad S; Bradley, Philip; Bradley, Robert K

2015-01-01

Whole-exome sequencing studies have identified common mutations affecting genes encoding components of the RNA splicing machinery in hematological malignancies. Here, we sought to determine how mutations affecting the 3' splice site recognition factor U2AF1 alter its normal role in RNA splicing. We find that U2AF1 mutations influence the similarity of splicing programs in leukemias, but do not give rise to widespread splicing failure. U2AF1 mutations cause differential splicing of hundreds of genes, affecting biological pathways such as DNA methylation (DNMT3B), X chromosome inactivation (H2AFY), the DNA damage response (ATR, FANCA), and apoptosis (CASP8). We show that U2AF1 mutations alter the preferred 3' splice site motif in patients, in cell culture, and in vitro. Mutations affecting the first and second zinc fingers give rise to different alterations in splice site preference and largely distinct downstream splicing programs. These allele-specific effects are consistent with a computationally predicted model of U2AF1 in complex with RNA. Our findings suggest that U2AF1 mutations contribute to pathogenesis by causing quantitative changes in splicing that affect diverse cellular pathways, and give insight into the normal function of U2AF1's zinc finger domains. © 2015 Ilagan et al.; Published by Cold Spring Harbor Laboratory Press.

[Role of mutations on the "hepatitis B virus 'a' determinant hotpoint" to the efficacy of hepatitis B vaccine].

PubMed

Zhang, Rui; Li, Rong-cheng; Zhu, Feng-cai; Li, Yan-ping; Liu, She-lan; Zhang, Xian-chen; Wang, Sheng-qi; Liang, Zheng-lun; Li, He-min; Zhuang, Hui

2007-04-01

To study how hepatitis B virus(HBV) 'a' determinant hotpoint mutations were influecing the hepatitis B vaccine efficacy. Primers were designed in HBV conservative region, and the degenerate probes for detecting 16 'a' determinant hotpoint mutations were developed for gene chips. Sensitivity and specificity of the gene chips were evaluated by clone sequencing. Sera of 47 pairs of mothers and infants with immune failure and 323 mothers of children with immune protection of HB vaccine were detected by the gene chips. Result from clone sequencing demonstrated that the gene chips were specific for the detection of 'a' determinant hotpoint mutations. The wild type of HBV was still dominant, with the prevalence of 78.66%, and the mutation frequencies of 126A, 145R, 126S-1, 126S-2, 129H, 144A, and 129R were 11.27%, 5.76%, 5.28%, 4.56%, 1.20%, 0.72% and 0.24%, respectively. The prevalence of 126A mutation was significantly higher than that of other mutations(P < 0.01). No significant differences were found in mother-infant transmission rates of 126A, 126S-1, 126S-2 and 145R variants. The currently available hepatitis B vaccine could block mother-infant transmission of 126A, 126S and 145R variants. It appears that there is no need to develop a new hepatitis B vaccine against 126 and 145 variants at present, but the consistent epidemiological surveillance on HBV mutants should be carried out.

CVID-associated TACI mutations affect autoreactive B cell selection and activation

PubMed Central

Romberg, Neil; Chamberlain, Nicolas; Saadoun, David; Gentile, Maurizio; Kinnunen, Tuure; Ng, Yen Shing; Virdee, Manmeet; Menard, Laurence; Cantaert, Tineke; Morbach, Henner; Rachid, Rima; Martinez-Pomar, Natalia; Matamoros, Nuria; Geha, Raif; Grimbacher, Bodo; Cerutti, Andrea; Cunningham-Rundles, Charlotte; Meffre, Eric

2013-01-01

Common variable immune deficiency (CVID) is an assorted group of primary diseases that clinically manifest with antibody deficiency, infection susceptibility, and autoimmunity. Heterozygous mutations in the gene encoding the tumor necrosis factor receptor superfamily member TACI are associated with CVID and autoimmune manifestations, whereas two mutated alleles prevent autoimmunity. To assess how the number of TACI mutations affects B cell activation and tolerance checkpoints, we analyzed healthy individuals and CVID patients carrying one or two TACI mutations. We found that TACI interacts with the cleaved, mature forms of TLR7 and TLR9 and plays an important role during B cell activation and the central removal of autoreactive B cells in healthy donors and CVID patients. However, only subjects with a single TACI mutation displayed a breached immune tolerance and secreted antinuclear antibodies (ANAs). These antibodies were associated with the presence of circulating B cell lymphoma 6–expressing T follicular helper (Tfh) cells, likely stimulating autoreactive B cells. Thus, TACI mutations may favor CVID by altering B cell activation with coincident impairment of central B cell tolerance, whereas residual B cell responsiveness in patients with one, but not two, TACI mutations enables autoimmune complications. PMID:24051380

Somatic mutations of GUCY2F, EPHA3, and NTRK3 in human cancers.

PubMed

Wood, Laura D; Calhoun, Eric S; Silliman, Natalie; Ptak, Janine; Szabo, Steve; Powell, Steve M; Riggins, Gregory J; Wang, Tian-Li; Yan, Hai; Gazdar, Adi; Kern, Scott E; Pennacchio, Len; Kinzler, Kenneth W; Vogelstein, Bert; Velculescu, Victor E

2006-10-01

Tyrosine kinases are major regulators of signal transduction cascades involved in cellular proliferation and have important roles in tumorigenesis. We have recently analyzed the tyrosine kinase gene family for alterations in human colorectal cancers and identified somatic mutations in seven members of this gene family. In this study we have used high-throughput sequencing approaches to further evaluate this subset of genes for genetic alterations in other human tumors. We identified somatic mutations in GUCY2F, EPHA3, and NTRK3 in breast, lung, and pancreatic cancers. Our results implicate these tyrosine kinase genes in the pathogenesis of other tumor types and suggest that they may be useful targets for diagnostic and therapeutic intervention in selected patients.

Multiplex Droplet Digital PCR Quantification of Recurrent Somatic Mutations in Diffuse Large B-Cell and Follicular Lymphoma.

PubMed

Alcaide, Miguel; Yu, Stephen; Bushell, Kevin; Fornika, Daniel; Nielsen, Julie S; Nelson, Brad H; Mann, Koren K; Assouline, Sarit; Johnson, Nathalie A; Morin, Ryan D

2016-09-01

A plethora of options to detect mutations in tumor-derived DNA currently exist but each suffers limitations in analytical sensitivity, cost, or scalability. Droplet digital PCR (ddPCR) is an appealing technology for detecting the presence of specific mutations based on a priori knowledge and can be applied to tumor biopsies, including formalin-fixed paraffin embedded (FFPE) tissues. More recently, ddPCR has gained popularity in its utility in quantifying circulating tumor DNA. We have developed a suite of novel ddPCR assays for detecting recurrent mutations that are prevalent in common B-cell non-Hodgkin lymphomas (NHLs), including diffuse large B-cell lymphoma, follicular lymphoma, and lymphoplasmacytic lymphoma. These assays allowed the differentiation and counting of mutant and wild-type molecules using one single hydrolysis probe. We also implemented multiplexing that allowed the simultaneous detection of distinct mutations and an "inverted" ddPCR assay design, based on employing probes matching wild-type alleles, capable of detecting the presence of multiple single nucleotide polymorphisms. The assays successfully detected and quantified somatic mutations commonly affecting enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) (Y641) and signal transducer and activator of transcription 6 (STAT6) (D419) hotspots in fresh tumor, FFPE, and liquid biopsies. The "inverted" ddPCR approach effectively reported any single nucleotide variant affecting either of these 2 hotspots as well. Finally, we could effectively multiplex hydrolysis probes targeting 2 additional lymphoma-related hotspots: myeloid differentiation primary response 88 (MYD88; L265P) and cyclin D3 (CCND3; I290R). Our suite of ddPCR assays provides sufficient analytical sensitivity and specificity for either the invasive or noninvasive detection of multiple recurrent somatic mutations in B-cell NHLs. © 2016 American Association for Clinical Chemistry.

ULK3 regulates cytokinetic abscission by phosphorylating ESCRT-III proteins

PubMed Central

Caballe, Anna; Wenzel, Dawn M; Agromayor, Monica; Alam, Steven L; Skalicky, Jack J; Kloc, Magdalena; Carlton, Jeremy G; Labrador, Leticia; Sundquist, Wesley I; Martin-Serrano, Juan

2015-01-01

The endosomal sorting complexes required for transport (ESCRT) machinery mediates the physical separation between daughter cells during cytokinetic abscission. This process is regulated by the abscission checkpoint, a genome protection mechanism that relies on Aurora B and the ESCRT-III subunit CHMP4C to delay abscission in response to chromosome missegregation. In this study, we show that Unc-51-like kinase 3 (ULK3) phosphorylates and binds ESCRT-III subunits via tandem MIT domains, and thereby, delays abscission in response to lagging chromosomes, nuclear pore defects, and tension forces at the midbody. Our structural and biochemical studies reveal an unusually tight interaction between ULK3 and IST1, an ESCRT-III subunit required for abscission. We also demonstrate that IST1 phosphorylation by ULK3 is an essential signal required to sustain the abscission checkpoint and that ULK3 and CHMP4C are functionally linked components of the timer that controls abscission in multiple physiological situations. DOI: http://dx.doi.org/10.7554/eLife.06547.001 PMID:26011858

Genetic and mechanistic evaluation for the mixed-field agglutination in B3 blood type with IVS3+5G>A ABO gene mutation.

PubMed

Chen, Ding-Ping; Tseng, Ching-Ping; Wang, Wei-Ting; Sun, Chien-Feng

2012-01-01

The ABO blood type B(3) is the most common B subtype in the Chinese population with a frequency of 1/900. Although IVS3+5G>A (rs55852701) mutation of B gene has been shown to associate with the development of B(3) blood type, genetic and mechanistic evaluation for the unique mixed-field agglutination phenotype has not yet been completely addressed. In this study, we analyzed 16 cases of confirmed B(3) individuals and found that IVS3+5G>A attributes to all cases of B(3). RT-PCR analyses revealed the presence of at least 7 types of aberrant B(3) splicing transcripts with most of the transcripts causing early termination and producing non-functional protein during translation. The splicing transcript without exon 3 that was predicted to generate functional B(3) glycosyltransferase lacking 19 amino acids at the N-terminal segment constituted only 0.9% of the splicing transcripts. Expression of the B(3) cDNA with exon 3 deletion in the K562 erythroleukemia cells revealed that the B(3) glycosyltransferase had only 40% of B(1) activity in converting H antigen to B antigen. Notably, the typical mixed-field agglutination of B(3)-RBCs can be mimicked by adding anti-B antibody to the K562-B(3) cells. This study thereby demonstrates that both aberrant splicing of B transcripts and the reduced B(3) glycosyltransferase activity contribute to weak B expression and the mixed-field agglutination of B(3), adding to the complexity for the regulatory mechanisms of ABO gene expression.

Regulation of normal B-cell differentiation and malignant B-cell survival by OCT2

PubMed Central

Hodson, Daniel J.; Shaffer, Arthur L.; Xiao, Wenming; Wright, George W.; Schmitz, Roland; Phelan, James D.; Yang, Yandan; Webster, Daniel E.; Rui, Lixin; Kohlhammer, Holger; Nakagawa, Masao; Waldmann, Thomas A.; Staudt, Louis M.

2016-01-01

The requirement for the B-cell transcription factor OCT2 (octamer-binding protein 2, encoded by Pou2f2) in germinal center B cells has proved controversial. Here, we report that germinal center B cells are formed normally after depletion of OCT2 in a conditional knockout mouse, but their proliferation is reduced and in vivo differentiation to antibody-secreting plasma cells is blocked. This finding led us to examine the role of OCT2 in germinal center-derived lymphomas. shRNA knockdown showed that almost all diffuse large B-cell lymphoma (DLBCL) cell lines are addicted to the expression of OCT2 and its coactivator OCA-B. Genome-wide chromatin immunoprecipitation (ChIP) analysis and gene-expression profiling revealed the broad transcriptional program regulated by OCT2 that includes the expression of STAT3, IL-10, ELL2, XBP1, MYC, TERT, and ADA. Importantly, genetic alteration of OCT2 is not a requirement for cellular addiction in DLBCL. However, we detected amplifications of the POU2F2 locus in DLBCL tumor biopsies and a recurrent mutation of threonine 223 in the DNA-binding domain of OCT2. This neomorphic mutation subtly alters the DNA-binding preference of OCT2, leading to the transactivation of noncanonical target genes including HIF1a and FCRL3. Finally, by introducing mutations designed to disrupt the OCT2–OCA-B interface, we reveal a requirement for this protein–protein interface that ultimately might be exploited therapeutically. Our findings, combined with the predominantly B-cell–restricted expression of OCT2 and the absence of a systemic phenotype in our knockout mice, suggest that an OCT2-targeted therapeutic strategy would be efficacious in both major subtypes of DLBCL while avoiding systemic toxicity. PMID:26993806

Metallic Borides, La 2 Re 3 B 7 and La 3 Re 2 B 5 , Featuring Extensive Boron–Boron Bonding

DOE PAGES

Bugaris, Daniel E.; Malliakas, Christos D.; Chung, Duck Young; ...

2016-01-26

We synthesized La 2Re 3B 7 and La 3Re 2B 5 in single-crystalline form from a molten La/Ni eutectic at 1000°C, in the first example of the flux crystal growth of ternary rare-earth rhenium borides. Both compounds crystallize in their own orthorhombic structure types, with La 2Re 3B 7 (space group Pcca) having lattice parameters a = 7.657(2) Å, b = 6.755(1) Å, and c = 11.617(2) Å, and La 3Re 2B 5 (space group Pmma) having lattice parameters a = 10.809(2) Å, b = 5.287(1) Å, and c = 5.747(1) Å. Furthermore, the compounds possess three-dimensional framework structures thatmore » are built up from rhenium boride polyhedra and boron-boron bonding. La 3Re 2B 5 features fairly common B 2 dumbbells, whereas La 2Re 3B 7 has unique one-dimensional subunits composed of alternating triangular B3 and trans-B4 zigzag chain fragments. Also observed in La 3Re 2B 5 is an unusual coordination of B by an octahedron of La atoms. Electronic band structure calculations predict that La 2Re 3B 7 is a semimetal, which is observed in the electrical resistivity data as measured on single crystals, with behavior obeying the Bloch-Grüneisen model and a room-temperature resistivity ρ300K of ~ 375 μΩ cm. The electronic band structure calculations also suggest that La 3Re 2B 5 is a regular metal.« less

Metallic Borides, La 2 Re 3 B 7 and La 3 Re 2 B 5 , Featuring Extensive Boron–Boron Bonding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bugaris, Daniel E.; Malliakas, Christos D.; Chung, Duck Young

We synthesized La 2Re 3B 7 and La 3Re 2B 5 in single-crystalline form from a molten La/Ni eutectic at 1000°C, in the first example of the flux crystal growth of ternary rare-earth rhenium borides. Both compounds crystallize in their own orthorhombic structure types, with La 2Re 3B 7 (space group Pcca) having lattice parameters a = 7.657(2) Å, b = 6.755(1) Å, and c = 11.617(2) Å, and La 3Re 2B 5 (space group Pmma) having lattice parameters a = 10.809(2) Å, b = 5.287(1) Å, and c = 5.747(1) Å. Furthermore, the compounds possess three-dimensional framework structures thatmore » are built up from rhenium boride polyhedra and boron-boron bonding. La 3Re 2B 5 features fairly common B 2 dumbbells, whereas La 2Re 3B 7 has unique one-dimensional subunits composed of alternating triangular B3 and trans-B4 zigzag chain fragments. Also observed in La 3Re 2B 5 is an unusual coordination of B by an octahedron of La atoms. Electronic band structure calculations predict that La 2Re 3B 7 is a semimetal, which is observed in the electrical resistivity data as measured on single crystals, with behavior obeying the Bloch-Grüneisen model and a room-temperature resistivity ρ300K of ~ 375 μΩ cm. The electronic band structure calculations also suggest that La 3Re 2B 5 is a regular metal.« less

Targeted 'next-generation' sequencing in anophthalmia and microphthalmia patients confirms SOX2, OTX2 and FOXE3 mutations.

PubMed

Jimenez, Nelson Lopez; Flannick, Jason; Yahyavi, Mani; Li, Jiang; Bardakjian, Tanya; Tonkin, Leath; Schneider, Adele; Sherr, Elliott H; Slavotinek, Anne M

2011-12-28

Anophthalmia/microphthalmia (A/M) is caused by mutations in several different transcription factors, but mutations in each causative gene are relatively rare, emphasizing the need for a testing approach that screens multiple genes simultaneously. We used next-generation sequencing to screen 15 A/M patients for mutations in 9 pathogenic genes to evaluate this technology for screening in A/M. We used a pooled sequencing design, together with custom single nucleotide polymorphism (SNP) calling software. We verified predicted sequence alterations using Sanger sequencing. We verified three mutations - c.542delC in SOX2, resulting in p.Pro181Argfs*22, p.Glu105X in OTX2 and p.Cys240X in FOXE3. We found several novel sequence alterations and SNPs that were likely to be non-pathogenic - p.Glu42Lys in CRYBA4, p.Val201Met in FOXE3 and p.Asp291Asn in VSX2. Our analysis methodology gave one false positive result comprising a mutation in PAX6 (c.1268A > T, predicting p.X423LeuextX*15) that was not verified by Sanger sequencing. We also failed to detect one 20 base pair (bp) deletion and one 3 bp duplication in SOX2. Our results demonstrated the power of next-generation sequencing with pooled sample groups for the rapid screening of candidate genes for A/M as we were correctly able to identify disease-causing mutations. However, next-generation sequencing was less useful for small, intragenic deletions and duplications. We did not find mutations in 10/15 patients and conclude that there is a need for further gene discovery in A/M.

Targeted 'Next-Generation' sequencing in anophthalmia and microphthalmia patients confirms SOX2, OTX2 and FOXE3 mutations

PubMed Central

2011-01-01

Background Anophthalmia/microphthalmia (A/M) is caused by mutations in several different transcription factors, but mutations in each causative gene are relatively rare, emphasizing the need for a testing approach that screens multiple genes simultaneously. We used next-generation sequencing to screen 15 A/M patients for mutations in 9 pathogenic genes to evaluate this technology for screening in A/M. Methods We used a pooled sequencing design, together with custom single nucleotide polymorphism (SNP) calling software. We verified predicted sequence alterations using Sanger sequencing. Results We verified three mutations - c.542delC in SOX2, resulting in p.Pro181Argfs*22, p.Glu105X in OTX2 and p.Cys240X in FOXE3. We found several novel sequence alterations and SNPs that were likely to be non-pathogenic - p.Glu42Lys in CRYBA4, p.Val201Met in FOXE3 and p.Asp291Asn in VSX2. Our analysis methodology gave one false positive result comprising a mutation in PAX6 (c.1268A > T, predicting p.X423LeuextX*15) that was not verified by Sanger sequencing. We also failed to detect one 20 base pair (bp) deletion and one 3 bp duplication in SOX2. Conclusions Our results demonstrated the power of next-generation sequencing with pooled sample groups for the rapid screening of candidate genes for A/M as we were correctly able to identify disease-causing mutations. However, next-generation sequencing was less useful for small, intragenic deletions and duplications. We did not find mutations in 10/15 patients and conclude that there is a need for further gene discovery in A/M. PMID:22204637

The dominant alopecia phenotypes Bareskin, Rex-denuded, and Reduced Coat 2 are caused by mutations in gasdermin 3.

PubMed

Runkel, F; Marquardt, A; Stoeger, C; Kochmann, E; Simon, D; Kohnke, B; Korthaus, D; Wattler, F; Fuchs, H; Hrabé de Angelis, M; Stumm, G; Nehls, M; Wattler, S; Franz, T; Augustin, M

2004-11-01

Reduced Coat 2 (Rco2) is an ENU-induced mutation affecting hair follicle morphogenesis by an abnormal and protracted catagen. We describe chromosomal mapping and molecular identification of the autosomal dominant Rco2 mutation. The Rco2 critical region on mouse chromosome 11 encompasses the alopecia loci, Bareskin (Bsk), Rex-denuded (Re(den)), Recombination induced mutation 3 (Rim3), and Defolliculated (Dfl). Recently, the gasdermin (Gsdm) gene was described as predominantly expressed in skin and gastric tissues. We provide evidence for a murine-specific gene cluster consisting of Gsdm and two closely related genes which we designate as Gsdm2 and Gsdm3. We show that Gsdm3 reflects a mutation hotspot and that Gsdm3 mutations cause alopecia in Rco2, Re(den), and Bsk mice. We infer a role of Gsdm3 during the catagen to telogen transition at the end of hair follicle morphogenesis and the formation of hair follicle-associated sebaceous glands.

Somatic mutation of EZH2 (Y641) in follicular and diffuse large B-cell lymphomas of germinal center origin | Office of Cancer Genomics

Cancer.gov

Morin et al. describe recurrent somatic mutations in EZH2, a polycomb group oncogene. The mutation, found in the SET domain of this gene encoding a histone methyltransferase, is found only in a subset of lymphoma samples. Specifically, EZH2 mutations are found in about 12% of follicular lymphomas (FL) and almost 23% of diffuse large B-cell lymphomas (DLBCL) of germinal center origin. This paper goes on to demonstrate that altered EZH2 proteins, corresponding to the most frequent mutations found in human lymphomas, have reduced activity using in vitro histone methylation assays.

Phosphorylation-Dependent 14-3-3 Binding to LRRK2 Is Impaired by Common Mutations of Familial Parkinson's Disease

PubMed Central

Li, Xianting; Wang, Qing Jun; Pan, Nina; Lee, Sangkyu; Zhao, Yingming; Chait, Brian T.; Yue, Zhenyu

2011-01-01

Background Recent studies show that mutations in Leucine Rich Repeat Kinase 2 (LRRK2) are the cause of the most common inherited and some sporadic forms of Parkinson's disease (PD). The molecular mechanism underlying the pathogenic role of LRRK2 mutations in PD remains unknown. Methodology/Principal Findings Using affinity purification and mass spectrometric analysis, we investigated phosphorylation sites and binding proteins of LRRK2 purified from mouse brain. We identified multiple phosphorylation sites at N-terminus of LRRK2 including S910, S912, S935 and S973. Focusing on the high stoichiometry S935 phosphorylation site, we developed an anti-pS935 specific antibody and showed that LRRK2 is constitutively phosphorylated at S935 in various tissues (including brain) and at different ages in mice. We find that 14-3-3 proteins (especially isoforms γ and η) bind LRRK2 and this binding depends on phosphorylation of S935. The binding of 14-3-3, with little effect on dimer formation of LRRK2, confers protection of the phosphorylation status of S935. Furthermore, we show that protein kinase A (PKA), but not LRRK2 kinase itself, can cause the phosphorylation of LRRK2 at S935 in vitro and in cell culture, suggesting that PKA is a potential upstream kinase that regulates LRRK2 function. Finally, our study indicates that the common PD-related mutations of LRRK2, R1441G, Y1699C and G2019S, decrease homeostatic phosphorylation levels of S935 and impair 14-3-3 binding of LRRK2. Conclusions/Significance LRRK2 is extensively phosphorylated in vivo, and the phosphorylation of specific sites (e.g. S935) determines 14-3-3 binding of LRRK2. We propose that 14-3-3 is an important regulator of LRRK2-mediated cellular functions. Our study suggests that PKA, a cAMP-dependent kinase involved in regulating dopamine physiology, is a potential upstream kinase that phosphorylates LRRK2 at S935. Furthermore, the reduction of phosphorylation/14-3-3 binding of LRRK2 due to the common familial

Prevalence of mutations within major hydrophilic region of hepatitis B virus and their correlation with genotypes among chronically infected patients in Egypt.

PubMed

Abu Zeid, Walaa M; Ramadan, Dalia I; Shemis, Mohamed A

2016-03-01

Mutations within the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) have been reported in relation to viral persistence by evasion from vaccine and immunotherapy, severity of liver disease and lack of detection by commercial kits. The aim of this study was to elucidate the circulation of hepatitis B virus (HBV) genotypes, subgenotypes and serotypes in Egypt, with recognition of the pattern and prevalence of MHR mutations possibly occurring during the course of the disease. Eighty-eight samples from patients with chronic HBV infection were included in the study. The surface protein-encoding gene (S gene) in the HBV genome was subjected to amplification and partial sequencing. Based on phylogenetic analysis, only genotype D was found circulating among patients. The majority of isolates belonged to subgenotype D3 (86.3%), followed by D7 (8%), then D5 (3.4%) and lastly D1 (2.3%). Two subtypes were identified: ayw2 (97%) and ayw3 (2%). The 'w' sub-determinant was not defined in one isolate (1%). A significant proportion of patients (13/88, 14.8%) exhibited mutations in the MHR, 10 of whom harboured mutations in the 'a' determinant region and three outside. The first loop comprised four patients with three mutations (P127S, P127T and Y134F). The second loop contained six patients, all with one mutation, S143L, which was most frequently encountered in this study (6.8%). We conclude that genotype D, subgenotype D3 and HBsAg subtype ayw2 are the most common types circulating in Egypt, which account for 100%, 86.3% and 97% of the population, respectively, with a moderate degree of MHR mutations. Copyright © 2016 Arab Journal of Gastroenterology. Published by Elsevier B.V. All rights reserved.

CD45RO enriches for activated, highly mutated human germinal center B cells

PubMed Central

Jackson, Stephen M.; Harp, Natessa; Patel, Darshna; Zhang, Jeffrey; Willson, Savannah; Kim, Yoon J.; Clanton, Christian

2007-01-01

To date, there is no consensus regarding the influence of different CD45 isoforms during peripheral B-cell development. Examining correlations between surface CD45RO expression and various physiologic processes ongoing during the germinal center (GC) reaction, we hypothesized that GC B cells, like T cells, that up-regulate surface RO should progressively acquire phenotypes commonly associated with activated, differentiating lymphocytes. GC B cells (IgD−CD38+) were subdivided into 3 surface CD45RO fractions: RO−, RO+/−, and RO+. We show here that the average number of mutations per IgVH transcript increased in direct correlation with surface RO levels. Conjunctional use of RO and CD69 further delineated low/moderately and highly mutated fractions. Activation-induced cytidine deaminase (AID) mRNA was slightly reduced among RO+ GC B cells, suggesting that higher mutation averages are unlikely due to elevated somatic mutation activity. Instead, RO+ GC B cells were negative for Annexin V, comprised mostly (93%) of CD77− centrocytes, and were enriched for CD69+ cells. Collectively, RO+ GC B cells occupy what seems to be a specialized niche comprised mostly of centrocytes that may be in transition between activation states. These findings are among the first to sort GC B cells into populations enriched for live mutated cells solely using a single extracellular marker. PMID:17644737

Genetic and Mechanistic Evaluation for the Mixed-Field Agglutination in B3 Blood Type with IVS3+5G>A ABO Gene Mutation

PubMed Central

Wang, Wei-Ting; Sun, Chien-Feng

2012-01-01

Background The ABO blood type B3 is the most common B subtype in the Chinese population with a frequency of 1/900. Although IVS3+5G>A (rs55852701) mutation of B gene has been shown to associate with the development of B3 blood type, genetic and mechanistic evaluation for the unique mixed-field agglutination phenotype has not yet been completely addressed. Methodology/Principal Findings In this study, we analyzed 16 cases of confirmed B3 individuals and found that IVS3+5G>A attributes to all cases of B3. RT-PCR analyses revealed the presence of at least 7 types of aberrant B3 splicing transcripts with most of the transcripts causing early termination and producing non-functional protein during translation. The splicing transcript without exon 3 that was predicted to generate functional B3 glycosyltransferase lacking 19 amino acids at the N-terminal segment constituted only 0.9% of the splicing transcripts. Expression of the B3 cDNA with exon 3 deletion in the K562 erythroleukemia cells revealed that the B3 glycosyltransferase had only 40% of B1 activity in converting H antigen to B antigen. Notably, the typical mixed-field agglutination of B3-RBCs can be mimicked by adding anti-B antibody to the K562-B3 cells. Conclusions/Significance This study thereby demonstrates that both aberrant splicing of B transcripts and the reduced B3 glycosyltransferase activity contribute to weak B expression and the mixed-field agglutination of B3, adding to the complexity for the regulatory mechanisms of ABO gene expression. PMID:22624005

Mutations in B3GALT6, which Encodes a Glycosaminoglycan Linker Region Enzyme, Cause a Spectrum of Skeletal and Connective Tissue Disorders

PubMed Central

Nakajima, Masahiro; Mizumoto, Shuji; Miyake, Noriko; Kogawa, Ryo; Iida, Aritoshi; Ito, Hironori; Kitoh, Hiroshi; Hirayama, Aya; Mitsubuchi, Hiroshi; Miyazaki, Osamu; Kosaki, Rika; Horikawa, Reiko; Lai, Angeline; Mendoza-Londono, Roberto; Dupuis, Lucie; Chitayat, David; Howard, Andrew; Leal, Gabriela F.; Cavalcanti, Denise; Tsurusaki, Yoshinori; Saitsu, Hirotomo; Watanabe, Shigehiko; Lausch, Ekkehart; Unger, Sheila; Bonafé, Luisa; Ohashi, Hirofumi; Superti-Furga, Andrea; Matsumoto, Naomichi; Sugahara, Kazuyuki; Nishimura, Gen; Ikegawa, Shiro

2013-01-01

Proteoglycans (PGs) are a major component of the extracellular matrix in many tissues and function as structural and regulatory molecules. PGs are composed of core proteins and glycosaminoglycan (GAG) side chains. The biosynthesis of GAGs starts with the linker region that consists of four sugar residues and is followed by repeating disaccharide units. By exome sequencing, we found that B3GALT6 encoding an enzyme involved in the biosynthesis of the GAG linker region is responsible for a severe skeletal dysplasia, spondyloepimetaphyseal dysplasia with joint laxity type 1 (SEMD-JL1). B3GALT6 loss-of-function mutations were found in individuals with SEMD-JL1 from seven families. In a subsequent candidate gene study based on the phenotypic similarity, we found that B3GALT6 is also responsible for a connective tissue disease, Ehlers-Danlos syndrome (progeroid form). Recessive loss-of-function mutations in B3GALT6 result in a spectrum of disorders affecting a broad range of skeletal and connective tissues characterized by lax skin, muscle hypotonia, joint dislocation, and spinal deformity. The pleiotropic phenotypes of the disorders indicate that B3GALT6 plays a critical role in a wide range of biological processes in various tissues, including skin, bone, cartilage, tendon, and ligament. PMID:23664117

Validation of Version 3.0 of the Breast Cancer Genetics Referral Screening Tool (B-RST™).

PubMed

Bellcross, Cecelia; Hermstad, April; Tallo, Christine; Stanislaw, Christine

2018-05-08

Despite increased awareness of hereditary breast and ovarian cancer among clinicians and the public, many BRCA1/2 mutation carriers remain unaware of their risk status. The Breast Cancer Genetics Referral Screening Tool (B-RST™) was created and validated to easily identify individuals at increased risk for hereditary breast and ovarian cancer for referral to cancer genetics services. The purpose of this study was to revise B-RST™ to maximize sensitivity against BRCA1/2 mutation status. We analyzed pedigrees of 277 individuals who had undergone BRCA1/2 testing to determine modifications to the B-RST™ 2.0 algorithm that would maximize sensitivity for mutations, while maintaining simplicity. We used McNemar's chi-square test to compare validation measures between the revised version (3.0) and the 2.0 version. Algorithmic changes made to B-RST™ 2.0 increased the sensitivity against BRCA1/2 mutation analysis from 71.1 to 94.0% (P < 0.0001). While specificity decreased, all screen-positive individuals were appropriate for cancer genetics referral, the primary purpose of the tool. Despite calls for BRCA1/2 population screening, there remains a critical need to identify those most at risk who should receive cancer genetics services. B-RST™ version 3.0 demonstrates high sensitivity for BRCA1/2 mutations, yet remains a simple and quick screening tool for at-risk individuals.

PIK3CA-mutated melanoma cells rely on cooperative signaling through mTORC1/2 for sustained proliferation.

PubMed

Silva, Jillian M; Deuker, Marian M; Baguley, Bruce C; McMahon, Martin

2017-05-01

Malignant conversion of BRAF- or NRAS-mutated melanocytes into melanoma cells can be promoted by PI3'-lipid signaling. However, the mechanism by which PI3'-lipid signaling cooperates with mutationally activated BRAF or NRAS has not been adequately explored. Using human NRAS- or BRAF-mutated melanoma cells that co-express mutationally activated PIK3CA, we explored the contribution of PI3'-lipid signaling to cell proliferation. Despite mutational activation of PIK3CA, melanoma cells were more sensitive to the biochemical and antiproliferative effects of broader spectrum PI3K inhibitors than to an α-selective PI3K inhibitor. Combined pharmacological inhibition of MEK1/2 and PI3K signaling elicited more potent antiproliferative effects and greater inhibition of the cell division cycle compared to single-agent inhibition of either pathway alone. Analysis of signaling downstream of MEK1/2 or PI3K revealed that these pathways cooperate to regulate cell proliferation through mTORC1-mediated effects on ribosomal protein S6 and 4E-BP1 phosphorylation in an AKT-dependent manner. Although PI3K inhibition resulted in cytostatic effects on xenografted NRAS Q61H /PIK3CA H1047R melanoma, combined inhibition of MEK1/2 plus PI3K elicited significant melanoma regression. This study provides insights as to how mutationally activated PIK3CA acts in concert with MEK1/2 signaling to cooperatively regulate mTORC1/2 to sustain PIK3CA-mutated melanoma proliferation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Role of gyrB Mutations in Pre-extensively and Extensively Drug-Resistant Tuberculosis in Thai Clinical Isolates

PubMed Central

Disratthakit, Areeya; Prammananan, Therdsak; Tribuddharat, Chanwit; Thaipisuttikul, Iyarit; Doi, Norio; Leechawengwongs, Manoon

2016-01-01

DNA gyrase mutations are a major cause of quinolone resistance in Mycobacterium tuberculosis. We therefore conducted the first comprehensive study to determine the diversity of gyrase mutations in pre-extensively drug-resistant (pre-XDR) (n = 71) and extensively drug-resistant (XDR) (n = 30) Thai clinical tuberculosis (TB) isolates. All pre-XDR-TB and XDR-TB isolates carried at least one mutation within the quinolone resistance-determining region of GyrA (G88A [1.1%], A90V [17.4%], S91P [1.1%], or D94A/G/H/N/V/Y [72.7%]) or GyrB (D533A [1.1%], N538D [1.1%], or E540D [2.2%]). MIC and DNA gyrase supercoiling inhibition assays were performed to determine the role of gyrase mutations in quinolone resistance. Compared to the MICs against M. tuberculosis H37Rv, the levels of resistance to all quinolones tested in the isolates that carried GyrA-D94G or GyrB-N538D (8- to 32-fold increase) were significantly higher than those in isolates bearing GyrA-D94A or GyrA-A90V (2- to 8-fold increase) (P < 0.01). Intriguingly, GyrB-E540D led to a dramatic resistance to later-generation quinolones, including moxifloxacin, gatifloxacin, and sparfloxacin (8- to 16-fold increases in MICs and 8.3- to 11.2-fold increases in 50% inhibitory concentrations [IC50s]). However, GyrB-E540D caused low-level resistance to early-generation quinolones, including ofloxacin, levofloxacin, and ciprofloxacin (2- to 4-fold increases in MICs and 1.5- to 2.0-fold increases in IC50s). In the present study, DC-159a was the most active antituberculosis agent and was little affected by the gyrase mutations described above. Our findings suggest that although they are rare, gyrB mutations have a notable role in quinolone resistance, which may provide clues to the molecular basis of estimating quinolone resistance levels for drug and dose selection. PMID:27297489

Photocatalytic self-cleaning transparent 2Bi2O3-B2O3 glass ceramics

NASA Astrophysics Data System (ADS)

Sharma, Sumeet Kumar; Singh, V. P.; Chauhan, Vishal S.; Kushwaha, H. S.; Vaish, Rahul

2017-09-01

Photocatalytic response of as-quenched and heat-treated 2Bi2O3-B2O3 glasses was studied. X ray diffraction reveals that the controlled heat treatment of glasses at 380 °C for 1 h, 2 h, and 3 h shows the formation of Bi4B2O9 crystals embedded in 2Bi2O3-B2O3 the host glass matrix. Scanning electron microscopic images reveal the presence of nanocrystallization in as-quenched glass. Significant photocatalytic activities were observed in as-quenched transparent glass. Photocatalytic activities were studied using the degradation of Resazurin as well as pharmaceutical 17 β-Estradiol under UV irradiation. Measurement of contact angle shows enhanced hydrophilicity with the increase in crystallization of the samples. Further, for as quenched 2Bi2O3-B2O3 glass ceramic, under UV irradiation, the water contact angle decreased from 92.7° to 39.5° and the sample surface transformed from hydrophobic to hydrophilic. Effective photocatalytic performance along with photoinduced hydrophilicity promotes 2Bi2O3-B2O3 glass ceramics in self-cleaning applications.

Mutation spectrum of MSH3-deficient HHUA/chr.2 cells reflects in vivo activity of the MSH3 gene product in mismatch repair.

PubMed

Tauchi, H; Komatsu, K; Ishizaki, K; Yatagai, F; Kato, T

2000-02-14

The endometrial tumor cell line HHUA carries mutations in two mismatch repair (MMR) genes MSH3 and MSH6. We have established an MSH3-deficient HHUA/chr.2 cell line by introducing human chromosome 2, which carries wild-type MSH6 and MSH2 genes, to HHUA cells. Introduction of chromosome 2 to HHUA cells partially restored G:G MMR activity to the cell extract and reduced the frequency of mutation at the hypoxanthine-guanine phosphoribosyltransferase (hprt*) locus to about 3% that of the parental HHUA cells, which is five-fold the frequency in MMR-proficient cells, indicating that the residual mutator activity in HHUA/chr.2 is due to an MSH3-deficiency in these cells. The spectrum of mutations occurring at the HPRT locus of HHUA/chr.2 was determined with 71 spontaneous 6TG(r) clones. Base substitutions and +/-1 bp frameshifts were the major mutational events constituting, respectively, 54% and 42% of the total mutations, and more than 70% of them occurred at A:T sites. A possible explanation for the apparent bias of mutations to A:T sites in HHUA/chr.2 is haploinsufficiency of the MSH6 gene on the transferred chromosome 2. Comparison of the mutation spectra of HHUA/chr.2 with that of the MSH6-deficient HCT-15 cell line [S. Ohzeki, A. Tachibana, K. Tatsumi, T. Kato, Carcinogenesis 18 (1997) 1127-1133.] suggests that in vivo the MutSalpha (MSH2:MSH6) efficiently repairs both mismatch and unpaired extrahelical bases, whereas MutSbeta (MSH2:MSH3) efficiently repairs extrahelical bases and repairs mismatch bases to a limited extent.

Response to 5-azacytidine in a patient with TET2-mutated angioimmunoblastic T-cell lymphoma and chronic myelomonocytic leukaemia preceded by an EBV-positive large B-cell lymphoma.

PubMed

Saillard, Colombe; Guermouche, Helene; Derrieux, Coralie; Bruneau, Julie; Frenzel, Laurent; Couronne, Lucile; Asnafi, Vahid; Macintyre, Elizabeth; Trinquand, Amélie; Lhermitte, Ludovic; Molina, Thierry; Suarez, Felipe; Lemonnier, Francois; Kosmider, Olivier; Delarue, Richard; Hermine, Olivier; Cheminant, Morgane

2017-12-01

We report the case of a patient with a history of Epstein-Barr virus-positive large B-cell lymphoma, who relapsed with an angioimmunoblastic T-cell lymphoma (AITL) associated with a chronic myelomonocytic leukaemia (CMML). We performed targeted next-generation sequencing on CMML and AITL DNA, which revealed mutations of TET2, DNMT3A, SRSF2, NRAS and IDH1, thus confirming that the spectrum of AITL mutations share similarities with myeloid disorders. The frequencies of TET2/DNMT3A and SRSF2 variants could support the hypothesis that TET2/DNMT3A mutations occurred in an early progenitor cell, which later progressed to both the AITL and CMML clones. Treatment with 5-azacytidine led to the complete remission of both diseases. Thus, targeting DNA methylation abnormalities in AITL may be an alternative strategy to chemotherapy. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

B-Raf mutation: a key player in molecular biology of cancer.

PubMed

Rahman, M A; Salajegheh, A; Smith, R A; Lam, A K-Y

2013-12-01

B-Raf is one of the more commonly mutated proto-oncogenes implicated in the development of cancers. In this review, we consider the mechanisms and clinical impacts of B-Raf mutations in cancer and discuss the implications for the patient in melanoma, thyroid cancer and colorectal cancer, where B-Raf mutations are particularly common. © 2013.

Characterization of Human Disease Phenotypes Associated with Mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR, and IFIH1

PubMed Central

Crow, Yanick J.; Chase, Diana S.; Schmidt, Johanna Lowenstein; Szynkiewicz, Marcin; Forte, Gabriella M.A.; Gornall, Hannah L.; Oojageer, Anthony; Anderson, Beverley; Pizzino, Amy; Helman, Guy; Abdel-Hamid, Mohamed S.; Abdel-Salam, Ghada M.; Ackroyd, Sam; Aeby, Alec; Agosta, Guillermo; Albin, Catherine; Allon-Shalev, Stavit; Arellano, Montse; Ariaudo, Giada; Aswani, Vijay; Babul-Hirji, Riyana; Baildam, Eileen M.; Bahi-Buisson, Nadia; Bailey, Kathryn M.; Barnerias, Christine; Barth, Magalie; Battini, Roberta; Beresford, Michael W.; Bernard, Geneviève; Bianchi, Marika; de Villemeur, Thierry Billette; Blair, Edward M.; Bloom, Miriam; Burlina, Alberto B.; Carpanelli, Maria Luisa; Carvalho, Daniel R.; Castro-Gago, Manuel; Cavallini, Anna; Cereda, Cristina; Chandler, Kate E.; Chitayat, David A.; Collins, Abigail E.; Corcoles, Concepcion Sierra; Cordeiro, Nuno J.V.; Crichiutti, Giovanni; Dabydeen, Lyvia; Dale, Russell C.; D’Arrigo, Stefano; De Goede, Christian G.E.L.; De Laet, Corinne; De Waele, Liesbeth M.H.; Denzler, Ines; Desguerre, Isabelle; Devriendt, Koenraad; Di Rocco, Maja; Fahey, Michael C.; Fazzi, Elisa; Ferrie, Colin D.; Figueiredo, António; Gener, Blanca; Goizet, Cyril; Gowrinathan, Nirmala R.; Gowrishankar, Kalpana; Hanrahan, Donncha; Isidor, Bertrand; Kara, Bülent; Khan, Nasaim; King, Mary D.; Kirk, Edwin P.; Kumar, Ram; Lagae, Lieven; Landrieu, Pierre; Lauffer, Heinz; Laugel, Vincent; La Piana, Roberta; Lim, Ming J.; Lin, Jean-Pierre S.-M.; Linnankivi, Tarja; Mackay, Mark T.; Marom, Daphna R.; Lourenço, Charles Marques; McKee, Shane A.; Moroni, Isabella; Morton, Jenny E.V.; Moutard, Marie-Laure; Murray, Kevin; Nabbout, Rima; Nampoothiri, Sheela; Nunez-Enamorado, Noemi; Oades, Patrick J.; Olivieri, Ivana; Ostergaard, John R.; Pérez-Dueñas, Belén; Prendiville, Julie S.; Ramesh, Venkateswaran; Rasmussen, Magnhild; Régal, Luc; Ricci, Federica; Rio, Marlène; Rodriguez, Diana; Roubertie, Agathe; Salvatici, Elisabetta; Segers, Karin A.; Sinha, Gyanranjan P.; Soler, Doriette; Spiegel, Ronen; Stödberg, Tommy I.; Straussberg, Rachel; Swoboda, Kathryn J.; Suri, Mohnish; Tacke, Uta; Tan, Tiong Y.; Naude, Johann te Water; Teik, Keng Wee; Thomas, Maya Mary; Till, Marianne; Tonduti, Davide; Valente, Enza Maria; Van Coster, Rudy Noel; van der Knaap, Marjo S.; Vassallo, Grace; Vijzelaar, Raymon; Vogt, Julie; Wallace, Geoffrey B.; Wassmer, Evangeline; Webb, Hannah J.; Whitehouse, William P.; Whitney, Robyn N.; Zaki, Maha S.; Zuberi, Sameer M.; Livingston, John H.; Rozenberg, Flore; Lebon, Pierre; Vanderver, Adeline; Orcesi, Simona; Rice, Gillian I.

2015-01-01

Aicardi–Goutières syndrome is an inflammatory disease occurring due to mutations in any of TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR or IFIH1. We report on 374 patients from 299 families with mutations in these seven genes. Most patients conformed to one of two fairly stereotyped clinical profiles; either exhibiting an in utero disease-onset (74 patients; 22.8% of all patients where data were available), or a post-natal presentation, usually within the first year of life (223 patients; 68.6%), characterized by a sub-acute encephalopathy and a loss of previously acquired skills. Other clinically distinct phenotypes were also observed; particularly, bilateral striatal necrosis (13 patients; 3.6%) and non-syndromic spastic paraparesis (12 patients; 3.4%). We recorded 69 deaths (19.3% of patients with follow-up data). Of 285 patients for whom data were available, 210 (73.7%) were profoundly disabled, with no useful motor, speech and intellectual function. Chilblains, glaucoma, hypothyroidism, cardiomyopathy, intracerebral vasculitis, peripheral neuropathy, bowel inflammation and systemic lupus erythematosus were seen frequently enough to be confirmed as real associations with the Aicardi-Goutieres syndrome phenotype. We observed a robust relationship between mutations in all seven genes with increased type I interferon activity in cerebrospinal fluid and serum, and the increased expression of interferon-stimulated gene transcripts in peripheral blood. We recorded a positive correlation between the level of cerebrospinal fluid interferon activity assayed within one year of disease presentation and the degree of subsequent disability. Interferon-stimulated gene transcripts remained high in most patients, indicating an ongoing disease process. On the basis of substantial morbidity and mortality, our data highlight the urgent need to define coherent treatment strategies for the phenotypes associated with mutations in the Aicardi–Goutières syndrome

Identification of a single ancestral CYP1B1 mutation in Slovak Gypsies (Roms) affected with primary congenital glaucoma.

PubMed

Plásilová, M; Stoilov, I; Sarfarazi, M; Kádasi, L; Feráková, E; Ferák, V

1999-04-01

Primary congenital glaucoma (PCG) is an autosomal recessive eye disease that occurs at an unusually high frequency in the ethnic isolate of Roms (Gypsies) in Slovakia. Recently, we linked the disease in this population to the GLC3A locus on 2p21. At this locus, mutations in the cytochrome P4501B1 (CYP1B1) gene have been identified as a molecular basis for this condition. Here, we report the results of CYP1B1 mutation screening of 43 PCG patients from 26 Slovak Rom families. A homozygous G-->A transition at nucleotide 1505 in the highly conserved region of exon 3 was detected in all families. This mutation results in the E387K substitution, which affects the conserved K helix region of the cytochrome P450 molecule. Determination of the CYP1B1 polymorphic background showed a common DNA haplotype in all patients, thus indicating that the E387K mutation in Roms has originated from a single ancestral mutational event. The Slovak Roms represent the first population in which PCG is found to result from a single mutation in the CYP1B1 gene, so that a founder effect is the most plausible explanation of its increased incidence. An ARMS-PCR assay has been developed for fast detection of this mutation, thus allowing direct DNA based prenatal diagnosis as well as gene carrier detection in this particular population. Screening of 158 healthy Roms identified 17 (10.8%) mutation carriers, indicating that the frequency of PCG in this population may be even higher than originally estimated.

Precore and core promoter mutations of hepatitis B virus and hepatitis B e antigen-negative chronic hepatitis B in Korea.

PubMed

Yoo, Byung Chul; Park, Joong-Won; Kim, Hyung Joon; Lee, Dong Ho; Cha, Young Ju; Park, Sill Moo

2003-01-01

The aims of this study were to determine the frequency of precore/core promoter mutations and hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB) in Korea. Patients with chronic hepatitis B virus (HBV) infection were tested for HBeAg, anti-HBe, liver profile and HBV-DNA by a branched DNA (bDNA) assay. Serum HBV-DNA was amplified by a polymerase chain reaction and the precore/core promoter sequence was determined. Among the 413 consecutive HBeAg-negative patients, 19.6% were bDNA-positive. Evidence of liver disease was found in 90.1% of bDNA-positive and 41.7% of bDNA-negative patients. Overall, 17.7% of HBeAg-negative patients had e-CHB. Precore mutation (A1896) was detected in 93.7% of HBeAg-negative bDNA-positive and 93.9% of HBeAg-negative bDNA-negative patients. In 59 HBeAg-positive patients, 78% had wild-type and 22% had a mixture of wild-type and A1896 mutant. Core promoter TA mutation was detected in 89.9% of HBeAg-negative bDNA-positive patients, 89.8% of HBeAg-negative bDNA-negative patients, and 74.6% of HBeAg-positive patients. No correlation was found between the presence of precore/core promoter mutations and HBV-DNA levels or disease severity. In Korean patients infected with HBV genotype C, precore mutation occurred almost invariably along with HBeAg seroconversion and core promoter TA mutation was frequent irrespective of viral replication levels or disease severity.

Functional avidity and IL-2/perforin production is linked to the emergence of mutations within HLA-B*5701-restricted epitopes and HIV-1 disease progression

PubMed Central

Buggert, Marcus; Norström, Melissa M; Salemi, Marco; Hecht, Frederick M; Karlsson, Annika C

2014-01-01

Viral escape from HIV-1-specific CD8+ T cells has been demonstrated in numerous studies previously. However, the qualitative features driving the emergence of mutations within epitopes are still unclear. In this study, we aimed to distinguish whether specific functional characteristics of HLA-B*5701-restricted CD8+ T cells influence the emergence of mutations in high-risk progressors (HRPs) versus low-risk progressors (LRPs). Single genome sequencing was performed to detect viral mutations (variants) within seven HLA-B*5701-restricted epitopes in Gag (n = 4) and Nef (n = 3) in six untreated HLA-B*5701 subjects followed from early infection up to seven years. Several well-characterized effector markers (IFN-γ, IL-2, MIP-1β, TNF, CD107a and perforin) were identified by flow cytometry following autologous (initial and emerging variant/s) epitope stimulations. This study demonstrates that specific functional attributes may facilitate the outgrowth of mutations within HLA-B*5701-restricted epitopes. A significantly lower fraction of IL-2 producing cells and a decrease in functional avidity and polyfunctional sensitivity were evident in emerging epitope variants compared to the initial autologous epitopes. Interestingly, the HRPs mainly drove these differences, while the LRPs maintained a directed and maintained functional response against emerging epitope variants. In addition, LRPs induced improved cell cycle progression and perforin up-regulation after autologous and emerging epitope variant stimulations in contrast to HRPs. The maintained quantitative and qualitative features of the CD8+ T cell responses in LRPs toward emerging epitope variants provide insights into why HLA-B*5701 subjects have different risks of HIV-1 disease progression. PMID:24740510

HLA-B27 Selects for Rare Escape Mutations that Significantly Impair Hepatitis C Virus Replication and Require Compensatory Mutations

PubMed Central

Neumann-Haefelin, Christoph; Oniangue-Ndza, Cesar; Kuntzen, Thomas; Schmidt, Julia; Nitschke, Katja; Sidney, John; Caillet-Saguy, Célia; Binder, Marco; Kersting, Nadine; Kemper, Michael W.; Power, Karen A.; Ingber, Susan; Reyor, Laura L.; Hills-Evans, Kelsey; Kim, Arthur Y.; Lauer, Georg M.; Lohmann, Volker; Sette, Alessandro; Henn, Matthew R.; Bressanelli, Stéphane; Thimme, Robert; Allen, Todd M.

2011-01-01

HLA-B27 is associated with spontaneous viral clearance in hepatitis C virus (HCV) infection. Viral escape within the immunodominant HLA-B27 restricted HCV-specific CD8+ T cell epitope NS5B2841-2849 (ARMILMTHF) has been shown to be limited by viral fitness costs as well as broad T cell cross-recognition, suggesting a potential mechanism of protection by HLA-B27. Here, we studied the subdominant HLA-B27 restricted epitope NS5B2936-2944 (GRAAICGKY) in order to further define the mechanisms of protection by HLA-B27. We identified a unique pattern of escape mutations within this epitope in a large cohort of HCV genotype 1a infected patients. The predominant escape mutations represented conservative substitutions at the main HLA-B27 anchor residue or a T cell receptor contact site, neither of which impaired viral replication capacity as assessed in a subgenomic HCV replicon system. In contrast, however, in a subset of HLA-B27+ subjects rare escape mutations arose at the HLA-B27 anchor residue R2937, which nearly abolished viral replication. Notably, these rare mutations only occurred in conjunction with the selection of two equally rare, and structurally proximal, upstream mutations. Co-expression of these upstream mutations with the rare escape mutations dramatically restored viral replication capacity from <5% to ≥70% of wild-type levels. Conclusion The selection of rare CTL escape mutations in this HLA-B27 restricted epitope dramatically impairs viral replicative fitness unless properly compensated. These data support a role for the targeting of highly-constrained regions by HLA-B27 in its ability to assert immune control of HCV and other highly variable pathogens. PMID:22006856

HIV-1 pol mutation frequency by subtype and treatment experience: extension of the HIVseq program to seven non-B subtypes.

PubMed

Rhee, Soo-Yon; Kantor, Rami; Katzenstein, David A; Camacho, Ricardo; Morris, Lynn; Sirivichayakul, Sunee; Jorgensen, Louise; Brigido, Luis F; Schapiro, Jonathan M; Shafer, Robert W

2006-03-21

HIVseq was developed in 2000 to make published data on the frequency of HIV-1 group M protease and reverse transcriptase (RT) mutations available in real time to laboratories and researchers sequencing these genes. Because most published protease and RT sequences belonged to subtype B, the initial version of HIVseq was based on this subtype. As additional non-B sequences from persons with well-characterized antiretroviral treatment histories have become available, the program has been extended to subtypes A, C, D, F, G, CRF01, and CRF02. The latest frequency of each protease and RT mutation according to subtype and drug-class exposure was calculated using published sequences in the Stanford HIV RT and Protease Sequence Database. Each mutation was hyperlinked to published reports of viruses containing the mutation. As of September 2005, the mean number of protease sequences per non-B subtype was 534 from protease inhibitor-naive persons and 133 from protease inhibitor-treated persons, representing 13.2% and 2.3%, respectively, of the data available for subtype B. The mean number of RT sequences per non-B subtype was 373 from RT inhibitor-naive persons and 288 from RT inhibitor-treated persons, representing 17.9% and 3.8%, respectively, of the data available for subtype B. HIVseq allows users to examine protease and RT mutations within the context of previously published sequences of these genes. The publication of additional non-B protease and RT sequences from persons with well-characterized treatment histories, however, will be required to perform the same types of analysis possible with the much larger number of subtype B sequences.

Mutations near the cleavage site of enterocin NKR-5-3B prepeptide reveal new insights into its biosynthesis.

PubMed

Perez, Rodney H; Sugino, Haruki; Ishibashi, Naoki; Zendo, Takeshi; Wilaipun, Pongtep; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

2017-04-01

Enterocin NKR-5-3B (Ent53B) is a 64-residue novel circular bacteriocin synthesized from an 87-residue prepeptide. Albeit through a still unknown mechanism, the EnkB1234 biosynthetic enzyme complex processes the prepeptide to yield its mature active, circular form. To gain insights into the key region/residue that plays a role in Ent53 maturation, several mutations near the cleavage site on the precursor peptide were generated. The interaction of the precursor peptide and EnkB1234 appeared to be hydrophobic in nature. At the Leu1 position, only mutations with helix structure-promoting hydrophobic residues (Ala, Ile, Val or Phe) were able to yield the mature Ent53B derivative. In this study, we also highlight the possible conformation-stabilizing role of the Ent53B leader peptide on the precursor peptide for its interaction with its biosynthetic enzyme complex. Any truncations of the leader peptide moiety interfered in the processing of the prepeptide. However, when propeptides of other circular bacteriocins (circularin A, leucocyclicin Q or lactocyclicin Q) were cloned at the C-terminus of the leader peptide, EnkB1234 could not process them to yield a mature bacteriocin. Taken together, these findings offer new perspectives in our understanding of the possible molecular mechanism of the biosynthesis of this circular bacteriocin. These new perspectives will help advance our current understanding to eventually elucidate circular bacteriocin biosynthesis. Understanding the biosynthetic mechanism of circular bacteriocins will materialize their application potential.

Brief Report: Cryopyrin-Associated Periodic Syndrome Caused by a Myeloid-Restricted Somatic NLRP3 Mutation.

PubMed

Zhou, Qing; Aksentijevich, Ivona; Wood, Geryl M; Walts, Avram D; Hoffmann, Patrycja; Remmers, Elaine F; Kastner, Daniel L; Ombrello, Amanda K

2015-09-01

To identify the cause of disease in an adult patient presenting with recent-onset fevers, chills, urticaria, fatigue, and profound myalgia, who was found to be negative for cryopyrin-associated periodic syndrome (CAPS) NLRP3 mutations by conventional Sanger DNA sequencing. We performed whole-exome sequencing and targeted deep sequencing using DNA from the patient's whole blood to identify a possible NLRP3 somatic mutation. We then screened for this mutation in subcloned NLRP3 amplicons from fibroblasts, buccal cells, granulocytes, negatively selected monocytes, and T and B lymphocytes and further confirmed the somatic mutation by targeted sequencing of exon 3. We identified a previously reported CAPS-associated mutation, p.Tyr570Cys, with a mutant allele frequency of 15% based on exome data. Targeted sequencing and subcloning of NLRP3 amplicons confirmed the presence of the somatic mutation in whole blood at a ratio similar to the exome data. The mutant allele frequency was in the range of 13.3-16.8% in monocytes and 15.2-18% in granulocytes. Notably, this mutation was either absent or present at a very low frequency in B and T lymphocytes, in buccal cells, and in the patient's cultured fibroblasts. Our findings indicate the possibility of myeloid-restricted somatic mosaicism in the pathogenesis of CAPS, underscoring the emerging role of massively parallel sequencing in clinical diagnosis. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Heat shock proteins stimulate APOBEC-3-mediated cytidine deamination in the hepatitis B virus.

PubMed

Chen, Zhigang; Eggerman, Thomas L; Bocharov, Alexander V; Baranova, Irina N; Vishnyakova, Tatyana G; Kurlander, Roger; Patterson, Amy P

2017-08-11

Apolipoprotein B mRNA-editing enzyme catalytic subunit 3 (APOBEC-3) enzymes are cytidine deaminases that are broadly and constitutively expressed. They are often up-regulated during carcinogenesis and candidate genes for causing the major single-base substitution in cancer-associated DNA mutations. Moreover, APOBEC-3s are involved in host innate immunity against many viruses. However, how APOBEC-3 mutational activity is regulated in normal and pathological conditions remains largely unknown. Heat shock protein levels are often elevated in both carcinogenesis and viral infection and are associated with DNA mutations. Here, using mutational analyses of hepatitis B virus (HBV), we found that Hsp90 stimulates deamination activity of APOBEC-3G (A3G), A3B, and A3C during co-expression in human liver HepG2 cells. Hsp90 directly stimulated A3G deamination activity when the purified proteins were used in in vitro reactions. Hsp40, -60, and -70 also had variable stimulatory effects in the cellular assay, but not in vitro Sequencing analyses further demonstrated that Hsp90 increased both A3G cytosine mutation efficiency on HBV DNA and total HBV mutation frequency. In addition, Hsp90 shifted A3G's cytosine region selection in HBV DNA and increased A3G's 5' nucleoside preference for deoxycytidine (5'-CC). Furthermore, the Hsp90 inhibitor 17- N -allylamino-17-demethoxygeldanamycin dose dependently inhibited A3G and A3B mutational activity on HBV viral DNA. Hsp90 knockdown by siRNA or by Hsp90 active-site mutation also decreased A3G activity. These results indicate that heat shock proteins, in particular Hsp90, stimulate APOBEC-3-mediated DNA deamination activity, suggesting a potential physiological role in carcinogenesis and viral innate immunity.

EZH2 is required for germinal center formation and somatic EZH2 mutations promote lymphoid transformation

PubMed Central

Béguelin, Wendy; Popovic, Relja; Teater, Matt; Jiang, Yanwen; Bunting, Karen L.; Rosen, Monica; Shen, Hao; Yang, Shao Ning; Wang, Ling; Ezponda, Teresa; Martinez-Garcia, Eva; Zhang, Haikuo; Zhang, Yupeng; Verma, Sharad K.; McCabe, Michael T.; Ott, Heidi M.; Van Aller, Glenn S.; Kruger, Ryan G.; Liu, Yan; McHugh, Charles F.; Scott, David W.; Chung, Young Rock; Kelleher, Neil; Shaknovich, Rita; Creasy, Caretha L.; Gascoyne, Randy D.; Wong, Kwok-Kin; Cerchietti, Leandro C.; Levine, Ross L.; Abdel-Wahab, Omar; Licht, Jonathan D.; Elemento, Olivier; Melnick, Ari M.

2013-01-01

The EZH2 histone methyltransferase is highly expressed in germinal center (GC) B-cells and targeted by somatic mutations in B-cell lymphomas. Here we find that EZH2 deletion or pharmacologic inhibition suppresses GC formation and functions in mice. EZH2 represses proliferation checkpoint genes and helps establish bivalent chromatin domains at key regulatory loci to transiently suppress GC B-cell differentiation. Somatic mutations reinforce these physiological effects through enhanced silencing of EZH2 targets in B-cells, and in human B-cell lymphomas. Conditional expression of mutant EZH2 in mice induces GC hyperplasia and accelerated lymphomagenesis in cooperation with BCL2. GCB-type DLBCLs are mostly addicted to EZH2, regardless of mutation status, but not the more differentiated ABC-type DLBCLs, thus clarifying the therapeutic scope of EZH2 targeting. PMID:23680150

18 CFR 3b.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE PERSONAL...

18 CFR 3b.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE PERSONAL...

18 CFR 3b.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE PERSONAL...

18 CFR 3b.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE PERSONAL...

CD79B and MYD88 Mutations in Splenic Marginal Zone Lymphoma

PubMed Central

Trøen, Gunhild; Warsame, Abdirashid; Delabie, Jan

2013-01-01

The mutation status of genes involved in the NF-κB signaling pathway in splenic marginal zone lymphoma was examined. DNA sequence analysis of four genes was performed: CD79A, CD79B, CARD11, and MYD88 that are activated through BCR signaling or Toll-like and interleukin signaling. A single point mutation was detected in the CD79B gene (Y196H) in one of ten SMZL cases. Additionally, one point mutation was identified in the MYD88 gene (L265P) in another SMZL case. No mutations were revealed in CD79A or CARD11 genes in these SMZL cases. Neither were mutations detected in these four genes studied in 13 control MZL samples. Interestingly, the two cases with mutations of CD79B and MYD88 showed increased numbers of immunoblasts spread among the smaller and typical marginal zone lymphoma cells. Although SMZL shows few mutations of NF-κB signaling genes, our results indicate that the presence of these mutations is associated with a higher histological grade. PMID:23378931

Mutations in B3GALT6, which encodes a glycosaminoglycan linker region enzyme, cause a spectrum of skeletal and connective tissue disorders.

PubMed

Nakajima, Masahiro; Mizumoto, Shuji; Miyake, Noriko; Kogawa, Ryo; Iida, Aritoshi; Ito, Hironori; Kitoh, Hiroshi; Hirayama, Aya; Mitsubuchi, Hiroshi; Miyazaki, Osamu; Kosaki, Rika; Horikawa, Reiko; Lai, Angeline; Mendoza-Londono, Roberto; Dupuis, Lucie; Chitayat, David; Howard, Andrew; Leal, Gabriela F; Cavalcanti, Denise; Tsurusaki, Yoshinori; Saitsu, Hirotomo; Watanabe, Shigehiko; Lausch, Ekkehart; Unger, Sheila; Bonafé, Luisa; Ohashi, Hirofumi; Superti-Furga, Andrea; Matsumoto, Naomichi; Sugahara, Kazuyuki; Nishimura, Gen; Ikegawa, Shiro

2013-06-06

Proteoglycans (PGs) are a major component of the extracellular matrix in many tissues and function as structural and regulatory molecules. PGs are composed of core proteins and glycosaminoglycan (GAG) side chains. The biosynthesis of GAGs starts with the linker region that consists of four sugar residues and is followed by repeating disaccharide units. By exome sequencing, we found that B3GALT6 encoding an enzyme involved in the biosynthesis of the GAG linker region is responsible for a severe skeletal dysplasia, spondyloepimetaphyseal dysplasia with joint laxity type 1 (SEMD-JL1). B3GALT6 loss-of-function mutations were found in individuals with SEMD-JL1 from seven families. In a subsequent candidate gene study based on the phenotypic similarity, we found that B3GALT6 is also responsible for a connective tissue disease, Ehlers-Danlos syndrome (progeroid form). Recessive loss-of-function mutations in B3GALT6 result in a spectrum of disorders affecting a broad range of skeletal and connective tissues characterized by lax skin, muscle hypotonia, joint dislocation, and spinal deformity. The pleiotropic phenotypes of the disorders indicate that B3GALT6 plays a critical role in a wide range of biological processes in various tissues, including skin, bone, cartilage, tendon, and ligament. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

[Spontaneous speech prosody and discourse analysis in schizophrenia and Fronto Temporal Dementia (FTD) patients].

PubMed

Martínez, Angela; Felizzola Donado, Carlos Alberto; Matallana Eslava, Diana Lucía

2015-01-01

Patients with schizophrenia and Frontotemporal Dementia (FTD) in their linguistic variants share some language characteristics such as the lexical access difficulties, disordered speech with disruptions, many pauses, interruptions and reformulations. For the schizophrenia patients it reflects a difficulty of affect expression, while for the FTD patients it reflects a linguistic issue. This study, through an analysis of a series of cases assessed Clinic both in memory and on the Mental Health Unit of HUSI-PUJ (Hospital Universitario San Ignacio), with additional language assessment (analysis speech and acoustic analysis), present distinctive features of the DFT in its linguistic variants and schizophrenia that will guide the specialist in finding early markers of a differential diagnosis. In patients with FTD language variants, in 100% of cases there is a difficulty understanding linguistic structure of complex type; and important speech fluency problems. In patients with schizophrenia, there are significant alterations in the expression of the suprasegmental elements of speech, as well as disruptions in discourse. We present how depth language assessment allows to reassess some of the rules for the speech and prosody analysis of patients with dementia and schizophrenia; we suggest how elements of speech are useful in guiding the diagnosis and correlate functional compromise in everyday psychiatrist's practice. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Prevalence and Characterization of Somatic Mutations in Chinese Aldosterone-Producing Adenoma Patients

PubMed Central

Wang, Baojun; Li, Xintao; Zhang, Xu; Ma, Xin; Chen, Luyao; Zhang, Yu; Lyu, Xiangjun; Tang, Yuzhe; Huang, Qingbo; Gao, Yu; Fan, Yang; Ouyang, Jinzhi

2015-01-01

Abstract Recently somatic mutations of KCNJ5, ATP1A1, ATP2B3, and CACNA1D have been identified in patients with aldosterone-producing adenoma (APA). The present study sequenced the DNA in the tissues and blood samples from Chinese patients with APA for KCNJ5, ATP1A1, ATP2B3, and CACNA1D gene mutations. Among the 114 patients, 86 (75.4%) were identified with KCNJ5 somatic mutations, including 3 previously reported (G151R, L168R, T158A) and 2 other unreported mutations. One patient presented with both a point mutation (E147) and an insertion mutation, whereas another had a 36-base duplication, G153_G164dup. No mutation of ATP1A1 and ATP2B3 in the known hotspots was identified and only 1 male patient was detected with a novel CACNA1D mutation, V748I. Unlike other studies, male and female patients had similar KCNJ5 mutation rates (76.9% vs 74.2%). Mutation carriers were younger and had lower preoperative potassium level, whereas male (but not female) mutation carriers had higher preoperative plasma aldosterone concentration and preoperative blood pressures. Mutation carriers also had higher LV mass index (LVMI) than nonmutation carriers. After surgery, LVMI improved significantly in the KCNJ5 mutation group but not in the nonmutation group. The mRNA expression of KCNJ5, CYP11B2, and ATP2B3 was higher in the KCNJ5-mutated APA tissues. Functional characterization of the 2 novel KCNJ5 mutations showed that they were associated with decreased proliferation, membrane depolarization, elevated secretion of aldosterone, and increased expression of CYP11B1 and CYP11B2. In conclusion, Chinese APA patients appear to have a high frequency of somatic KCNJ5 mutation. Mutation prevalence rates are similar among men and women and 2 novel mutations are identified. KCNJ5-mutated patients benefit more from surgical resection of APA than nonmutated patients. PMID:25906099

IDH1 and IDH2 mutations in postoperative diffuse glioma-associated epilepsy.

PubMed

Neal, Andrew; Kwan, Patrick; O'Brien, Terence John; Buckland, Michael E; Gonzales, Michael; Morokoff, Andrew

2018-01-01

Isocitrate dehydrogenase 1 and 2 mutations (IDH1/2) have an established association with preoperative seizures in patients with grades II-IV diffuse gliomas. Here, we examined if IDH1/2 mutations are a biomarker of postoperative seizure frequency. This was a retrospective study. Patients with grades II-IV supratentorial diffuse glioma, immunohistochemistry results of IDH1-R132H, and antiepileptic drug (AED) prescribed postoperatively were included. The primary outcome was seizure frequency over the first 12 postoperative months: Group A - postoperative seizure freedom; Group B - 1-11 seizures over 12months (less than one seizure per month); and Group C - greater than one seizure per month. Rates of IDH1-R132H mutation were compared between the three outcome groups in univariate and multivariate analyses. Subgroup analysis was performed in 64 patients with IDH1/2 pyrosequencing data. One hundred cases were included in the analysis: 30.0% grade II, 20.0% grade III, and 50.0% grade IV gliomas. Group B patients averaged 1 seizure over 12months, compared with 2 seizures per month in Group C. Isocitrate dehydrogense 1-R132H mutation was present in 29.3% (17/58) of Group A, 18.2% (14/22) of Group B, and 70.0% (14/20) of Group C patients (p=0.001). On multivariate analysis, after controlling for preoperative seizure, grade, and temporal tumor location, IDH1-R132H was associated with Group C when compared with both Group A (RR 4.75, p=0.032) and Group B (RR 9.70, p=0.012). In the subgroup with IDH1/2 molecular data, an IDH1/2 mutation was present in 64.7% (22/34) of Group A, 28.6% (4/14) of Group C, and 87.5% (14/16) of Group C patients (p=0.004). In patients with supratentorial diffuse gliomas, IDH1-R132H mutations are associated with a more severe phenotype of postoperative epilepsy. These findings support further research into IDH mutations, and the potential for an antiepileptic therapeutic effect of their inhibitors, in patients with glioma-associated epilepsy

Genotype-phenotype correlation and identification of two novel SRD5A2 mutations in 33 Chinese patients with hypospadias.

PubMed

Yuan, Shimin; Meng, Lanlan; Zhang, Yanan; Tu, Chaofeng; Du, Juan; Li, Wen; Liang, Ping; Lu, Guangxiu; Tan, Yue-Qiu

2017-09-01

Hypospadias, a common congenital malformation of male external genitalia, is characterized mainly by an aberrant opening of the urethra on the ventral side of the penis. Depending on the severity of the disease, it can be classified into three types: anterior, middle, and posterior. In our study, 33 patients with hypospadias were recruited, including eight with anterior hypospadias and 25 with posterior hypospadias. We performed mutation analysis of the SRD5A2, AR and HSD17B3 genes in these patients. Eight different SRD5A2 mutations were detected in 15 patients with posterior hypospadias (60%, 15/25), including six previously described mutations (p.Q6X, Q71X, p.L20P, p.G203S, p.R227Q, and p.R246Q) and two novel mutations (p.G196R and p.L73Pfs ∗ 17). One AR gene mutation (p.A597T) was found in a patient and no HSD17B3 mutations were detected. Additionally, we carried out routine semen analyses in all adult patients. Combing mutation analysis with semen examination results, showed that whole five adult patients who carried SRD5A2 mutations had abnormal semen quality. In summary, all the detected mutations were responsible for the clinical features observed in these 16 patients. Our data suggest that mutations of the SRD5A2 gene are the main causes of posterior hypospadias and seem to affect the semen quality of adult patients, whereas mutations in AR and HSD17B3 gene were rare in these hypospadias patients. Our study expanded the SRD5A2 mutation spectrum in the Han Chinese population and provided useful information for genetic and reproductive counselling for patients with hypospadias. Copyright © 2017 Elsevier Inc. All rights reserved.

21 CFR 73.3123 - 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one. 73.3123 Section 73.3123 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

21 CFR 73.3123 - 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one. 73.3123 Section 73.3123 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

21 CFR 73.3123 - 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one. 73.3123 Section 73.3123 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

21 CFR 73.3123 - 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one. 73.3123 Section 73.3123 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

21 CFR 73.3123 - 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false 6-Ethoxy-2-(6-ethoxy-3-oxobenzo[b]thien-2(3H)-ylidene) benzo[b]thiophen-3 (2H)-one. 73.3123 Section 73.3123 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

De novo germline and postzygotic mutations in AKT3, PIK3R2 and PIK3CA cause a spectrum of related megalencephaly syndromes.

PubMed

Rivière, Jean-Baptiste; Mirzaa, Ghayda M; O'Roak, Brian J; Beddaoui, Margaret; Alcantara, Diana; Conway, Robert L; St-Onge, Judith; Schwartzentruber, Jeremy A; Gripp, Karen W; Nikkel, Sarah M; Worthylake, Thea; Sullivan, Christopher T; Ward, Thomas R; Butler, Hailly E; Kramer, Nancy A; Albrecht, Beate; Armour, Christine M; Armstrong, Linlea; Caluseriu, Oana; Cytrynbaum, Cheryl; Drolet, Beth A; Innes, A Micheil; Lauzon, Julie L; Lin, Angela E; Mancini, Grazia M S; Meschino, Wendy S; Reggin, James D; Saggar, Anand K; Lerman-Sagie, Tally; Uyanik, Gökhan; Weksberg, Rosanna; Zirn, Birgit; Beaulieu, Chandree L; Majewski, Jacek; Bulman, Dennis E; O'Driscoll, Mark; Shendure, Jay; Graham, John M; Boycott, Kym M; Dobyns, William B

2012-06-24

Megalencephaly-capillary malformation (MCAP) and megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndromes are sporadic overgrowth disorders associated with markedly enlarged brain size and other recognizable features. We performed exome sequencing in 3 families with MCAP or MPPH, and our initial observations were confirmed in exomes from 7 individuals with MCAP and 174 control individuals, as well as in 40 additional subjects with megalencephaly, using a combination of Sanger sequencing, restriction enzyme assays and targeted deep sequencing. We identified de novo germline or postzygotic mutations in three core components of the phosphatidylinositol 3-kinase (PI3K)-AKT pathway. These include 2 mutations in AKT3, 1 recurrent mutation in PIK3R2 in 11 unrelated families with MPPH and 15 mostly postzygotic mutations in PIK3CA in 23 individuals with MCAP and 1 with MPPH. Our data highlight the central role of PI3K-AKT signaling in vascular, limb and brain development and emphasize the power of massively parallel sequencing in a challenging context of phenotypic and genetic heterogeneity combined with postzygotic mosaicism.

The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development.

PubMed

Ortega-Molina, Ana; Boss, Isaac W; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A; Gascoyne, Randy D; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M; Wendel, Hans-Guido

2015-10-01

The gene encoding the lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma and diffuse large B cell lymphoma; however, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center involution and impedes B cell differentiation and class switch recombination. Integrative genomic analyses indicate that KMT2D affects methylation of lysine 4 on histone H3 (H3K4) and expression of a set of genes, including those in the CD40, JAK-STAT, Toll-like receptor and B cell receptor signaling pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3 and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell-activating pathways.

PIK3CA oncogenic mutations represent a major mechanism of resistance to trastuzumab in HER2/neu overexpressing uterine serous carcinomas.

PubMed

Black, Jonathan D; Lopez, Salvatore; Cocco, Emiliano; Bellone, Stefania; Altwerger, Gary; Schwab, Carlton L; English, Diana P; Bonazzoli, Elena; Predolini, Federica; Ferrari, Francesca; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Santin, Alessandro D

2015-09-29

We evaluated the role of PIK3CA-mutations as mechanism of resistance to trastuzumab in primary HER2/neu-amplified uterine-serous-carcinoma (USC) cell lines. Fifteen whole-exome-sequenced USC cell lines were tested for HER2/neu-amplification and PIK3CA-mutations. Four HER2/neu-amplified USC (2-harbouring wild-type-PIK3CA-genes and 2-harbouring oncogenic-PIK3CA-mutations) were evaluated in in vitro dose-titration-proliferation-assays, cell-viability and HER2 and S6-protein-phosphorylation after exposure to trastuzumab. USC harbouring wild-type-PIK3CA were transfected with plasmids encoding oncogenic PIK3CA-mutations (i.e., H1047R/R93Q) and exposed to trastuzumab. Finally, trastuzumab efficacy was tested by using two USC xenograft mouse models. Seven out of fifteen (46%) of the USC cell lines were HER2/neu-amplified by fluorescence in situ hybridisation. Within these tumours four out of seven (57%) were found to harbour oncogenic PIK3CA-mutations vs two out of eight (25%) of the HER2/neu not amplified cell lines (P=0.01). HER2/neu-amplified/PIK3CA-mutated USC were highly resistant to trastuzumab when compared with HER2/neu-amplified/wild-type-PIK3CA cell lines (P=0.02). HER2/neu-amplified/PIK3CA wild-type cell lines transfected with oncogenic PIK3CA-mutations increased their resistance to trastuzumab (P<0.0001). Trastuzumab was effective in reducing tumour growth (P=0.001) and improved survival (P=0.0001) in mouse xenografts harbouring HER2-amplified/PIK3CA wild-type USC but not in HER2-amplified/PIK3CA-mutated tumours. Oncogenic PIK3CA mutations are common in HER2/neu-amplified USC and may constitute a major mechanism of resistance to trastuzumab treatment.

Rett-like Severe Encephalopathy Caused by a De Novo GRIN2B Mutation Is Attenuated by D-serine Dietary Supplement.

PubMed

Soto, David; Olivella, Mireia; Grau, Cristina; Armstrong, Judith; Alcon, Clara; Gasull, Xavier; Gómez de Salazar, Macarena; Gratacòs-Batlle, Esther; Ramos-Vicente, David; Fernández-Dueñas, Víctor; Ciruela, Francisco; Bayés, Àlex; Sindreu, Carlos; López-Sala, Anna; García-Cazorla, Àngels; Altafaj, Xavier

2018-01-15

N-Methyl-D-aspartate receptors (NMDARs) play pivotal roles in synaptic development, plasticity, neural survival, and cognition. Despite recent reports describing the genetic association between de novo mutations of NMDAR subunits and severe psychiatric diseases, little is known about their pathogenic mechanisms and potential therapeutic interventions. Here we report a case study of a 4-year-old Rett-like patient with severe encephalopathy carrying a missense de novo mutation in GRIN2B(p.P553T) coding for the GluN2B subunit of NMDAR. We generated a dynamic molecular model of mutant GluN2B-containing NMDARs. We expressed the mutation in cell lines and primary cultures, and we evaluated the putative morphological, electrophysiological, and synaptic plasticity alterations. Finally, we evaluated D-serine administration as a therapeutic strategy and translated it to the clinical practice. Structural molecular modeling predicted a reduced pore size of mutant NMDARs. Electrophysiological recordings confirmed this prediction and also showed gating alterations, a reduced glutamate affinity associated with a strong decrease of NMDA-evoked currents. Moreover, GluN2B(P553T)-expressing neurons showed decreased spine density, concomitant with reduced NMDA-evoked currents and impaired NMDAR-dependent insertion of GluA1 at stimulated synapses. Notably, the naturally occurring coagonist D-serine was able to attenuate hypofunction of GluN2B(p.P553T)-containing NMDARs. Hence, D-serine dietary supplementation was initiated. Importantly, the patient has shown remarkable motor, cognitive, and communication improvements after 17 months of D-serine dietary supplementation. Our data suggest that hypofunctional NMDARs containing GluN2B(p.P553T) can contribute to Rett-like encephalopathy and that their potentiation by D-serine treatment may underlie the associated clinical improvement. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Contribution of EGFR and ErbB-3 Heterodimerization to the EGFR Mutation-Induced Gefitinib- and Erlotinib-Resistance in Non-Small-Cell Lung Carcinoma Treatments.

PubMed

Wang, Debby D; Ma, Lichun; Wong, Maria P; Lee, Victor H F; Yan, Hong

2015-01-01

EGFR mutation-induced drug resistance has become a major threat to the treatment of non-small-cell lung carcinoma. Essentially, the resistance mechanism involves modifications of the intracellular signaling pathways. In our work, we separately investigated the EGFR and ErbB-3 heterodimerization, regarded as the origin of intracellular signaling pathways. On one hand, we combined the molecular interaction in EGFR heterodimerization with that between the EGFR tyrosine kinase and its inhibitor. For 168 clinical subjects, we characterized their corresponding EGFR mutations using molecular interactions, with three potential dimerization partners (ErbB-2, IGF-1R and c-Met) of EGFR and two of its small molecule inhibitors (gefitinib and erlotinib). Based on molecular dynamics simulations and structural analysis, we modeled these mutant-partner or mutant-inhibitor interactions using binding free energy and its components. As a consequence, the mutant-partner interactions are amplified for mutants L858R and L858R_T790M, compared to the wild type EGFR. Mutant delL747_P753insS represents the largest difference between the mutant-IGF-1R interaction and the mutant-inhibitor interaction, which explains the shorter progression-free survival of an inhibitor to this mutant type. Besides, feature sets including different energy components were constructed, and efficient regression trees were applied to map these features to the progression-free survival of an inhibitor. On the other hand, we comparably examined the interactions between ErbB-3 and its partners (EGFR mutants, IGF-1R, ErbB-2 and c-Met). Compared to others, c-Met shows a remarkably-strong binding with ErbB-3, implying its significant role in regulating ErbB-3 signaling. Moreover, EGFR mutants corresponding to poor clinical outcomes, such as L858R_T790M, possess lower binding affinities with ErbB-3 than c-Met does. This may promote the communication between ErbB-3 and c-Met in these cancer cells. The analysis verified

FGFR3, PIK3CA and RAS mutations in benign lichenoid keratosis.

PubMed

Groesser, L; Herschberger, E; Landthaler, M; Hafner, C

2012-04-01

Benign lichenoid keratoses (BLKs) are solitary skin lesions which have been proposed to represent a regressive form of pre-existent epidermal tumours such as solar lentigo or seborrhoeic keratosis. However, the genetic basis of BLK is unknown. FGFR3, PIK3CA and RAS mutations have been shown to be involved in the pathogenesis of seborrhoeic keratosis and solar lentigo. We thus investigated whether these mutations are also present in BLK. After manual microdissection and DNA isolation, 52 BLKs were screened for FGFR3, PIK3CA and RAS hotspot mutations using SNaPshot(®) multiplex assays. We identified 6/52 (12%) FGFR3 mutations, 10/52 (19%) PIK3CA mutations, 6/52 (12%) HRAS mutations and 2/52 (4%) KRAS mutations. FGFR3 and RAS mutations were mutually exclusive. One BLK showed a simultaneous PIK3CA and HRAS mutation. In nine BLKs with a mutation, nonlesional control tissue from the epidermal margin and the dermal lymphocytic infiltrate were wild-type, indicating that these mutations are somatic. To demonstrate that these findings are specific, 10 samples of lichen planus were analysed without evidence for FGFR3, PIK3CA or RAS mutations. Our results indicate that FGFR3, PIK3CA and RAS mutations are present in approximately 50% of BLKs. These findings support the concept on the molecular genetic level that at least a proportion of BLKs represents regressive variants resulting from former benign epidermal tumours such as seborrhoeic keratosis and solar lentigo. © 2011 The Authors. BJD © 2011 British Association of Dermatologists 2011.

JAK2 mutation in a patient with CLL with coexistent myeloproliferative neoplasm (MPN).

PubMed

Kodali, Srinivas; Chen, Chi; Rathnasabapathy, Chenthilmurugan; Wang, Jen Chin

2009-12-01

JAK2 mutation has not been described in patients with chronic lymphocytic leukemia (CLL). We found JAK2 mutation in a patient with CLL and coexisting myeloproliferative neoplasm (MPN). In this patient, we demonstrated the presence of the JAK2 mutation in CD34(+) progenitor cells, myeloid lineage cells, megakaryocytes, B lymphocytes but not in T lymphocytes. This case represents the first case report of JAK2 mutation in CLL and may also suggest that, JAK2 mutation most likely represents a secondary event from primary gene mutations involving the primitive stem cells which give rise to MPN and CLL. Furthermore, in this case, we believe that we are the first to demonstrate that JAK2 mutation in myeloid and B lymphoid cells but not T lymphocytes in a case of coexisting CLL and MPN.

Analysis of S gene mutation of the hepatitis B virus in adult liver transplant recipients showing resistance to hepatitis B immunoglobulin therapy.

PubMed

Park, G-C; Hwang, S; Ahn, C-S; Kim, K-H; Moon, D-B; Ha, T-Y; Song, G-W; Jung, D-H; Shin, Y W; Kim, S-H; Chang, K-H; Namgoong, J-M; Park, C-S; Park, H-W; Park, Y-H; Kang, S-H; Jung, B-H; Lee, S-G

2013-10-01

A considerable proportion of recipients of liver transplantations who are presented hepatitis B immunoglobulin (HBIG) monotherapy for hepatitis B virus (HBV) prophylaxis develop HBIG resistance. In this study, we investigated the mutation patterns in the major hydrophilic region (MHR) of amino acid sequences 100 to 160. Using the gene sequence analyzer for amino acid sequences 0 to 226 in the S/pre-S region we analyzed blood samples of 15 patients showing HBIG resistance after high-dose HBIG prophylaxis. Various mutations in the MHR were observed in 14/15 samples: Gly145Arg mutation in 8/13 Adr subtype and 1/2 Ayw subtype samples (60%). The next most common mutation was Gly165Trp in 8/13 Adr subtype but neither of 2 Ayw subtype samples (53.3%). Concurrent antiviral resistance was noted in 5 patients: lamivudine (n = 5), or entecavir (n = 3), but not adefovir, suggesting the occurrence of simultaneous, antiviral cross-resistances. Two patients underwent retransplantation due to the progression of HBV infection despite vigorous antiviral therapy. At diagnosis of HBV recurrence, the mean HBV DNA load was 6.5 × 10(6) copies/mL; 4 patients showed paradoxical coexistence of anti-HBs and HBsAg. Currently, 2 subjects show low-level HBV DNA replication in peripheral blood, although the other 12 had no DNA replication after prolonged antiviral therapy. This study suggested that various mutations in the "a" determinant were associated with HBIG resistance. Since treatment failure to rescue antiviral therapy was often associated with delayed detection of HBV recurrence rather than concurrent antiviral resistance, frequent HBV surveillance using more sensitive screening tests, such as HBeAg and HBV DNA polymerase chain reaction assay, seems to be mandatory. Copyright © 2013 Elsevier Inc. All rights reserved.

TAC3 and TACR3 mutations in familial hypogonadotropic hypogonadism reveal a key role for Neurokinin B in the central control of reproduction.

PubMed

Topaloglu, A Kemal; Reimann, Frank; Guclu, Metin; Yalin, Ayse Serap; Kotan, L Damla; Porter, Keith M; Serin, Ayse; Mungan, Neslihan O; Cook, Joshua R; Imamoglu, Sazi; Akalin, N Sema; Yuksel, Bilgin; O'Rahilly, Stephen; Semple, Robert K

2009-03-01

The timely secretion of gonadal sex steroids is essential for the initiation of puberty, the postpubertal maintenance of secondary sexual characteristics and the normal perinatal development of male external genitalia. Normal gonadal steroid production requires the actions of the pituitary-derived gonadotropins, luteinizing hormone and follicle-stimulating hormone. We report four human pedigrees with severe congenital gonadotropin deficiency and pubertal failure in which all affected individuals are homozygous for loss-of-function mutations in TAC3 (encoding Neurokinin B) or its receptor TACR3 (encoding NK3R). Neurokinin B, a member of the substance P-related tachykinin family, is known to be highly expressed in hypothalamic neurons that also express kisspeptin, a recently identified regulator of gonadotropin-releasing hormone secretion. These findings implicate Neurokinin B as a critical central regulator of human gonadal function and suggest new approaches to the pharmacological control of human reproduction and sex hormone-related diseases.

[A study on mutations of the overlapping hepatitis B virus surface and polymerase gene in patients with HBV reinfection after liver transplantations].

PubMed

Song, Hong-li; Shen, Zhong-yang; Wang, Jian; Zheng, Wei-ping; Wang, Zheng-lu

2008-04-01

To investigate the influence of combined hepatitis B immune globulin (HBIG) and lamivudine (LMV) treatment on hepatitis B virus (HBV) surface antigen and polymerase overlapping gene mutations in HBV reinfected liver transplant recipients. From June 2002 to December 2003, 320 patients who underwent liver transplantations due to HBV-related end-stage liver diseases were followed-up for 1.5 to 3 years postoperatively. Fourteen patients developed HBV reinfection. They had LMV before their liver transplantations and had LMV and HBIG after the transplantations to prevent HBV infections. Their serum levels of HBV DNA were measured by polymerase chain reaction. Gene sequencing method was used to analyze HBV genotype and mutations of the S gene. Micro-particle enzyme immunoassay was used to measure the serum concentration of HBIG. (1) There was no obvious difference in the number of amino acid mutation sites in S and P regions before and after the transplantations. (2) The HBV genotypes were B-type (n=2) and C-type (n=12) in the reinfected group before the transplantations, and genotypes after the transplantations remained the same. (3) HBIG concentrations were 0 U/L in 7 patients, less than 100 U/L in 5 patients, and more than 100 U/L in 2 patients. Mutations were detected as I126S, T131N, S143T and G145R in 'a' determinant and L110F, I113S, T160K in up- or down-stream of 'a' determinant. (4) Mutations in S gene caused missense mutation in the surface antigen region. These mutations also caused corresponding missense mutations in the polymerase region. The missense mutation in the polymerase region involved lamivudine mutation sites and other mutation sites. Immunosuppressant therapy has no obvious influence on the numbers of mutations, but it can influence the sites of the mutations. Besides 'a' determinant mutations, there exist mutations in up- or down-streams of 'a' determinant and they may cause HBV reinfection.

Characterisation of mutations of the phosphoinositide-3-kinase regulatory subunit, PIK3R2, in perisylvian polymicrogyria: a next-generation sequencing study.

PubMed

Mirzaa, Ghayda M; Conti, Valerio; Timms, Andrew E; Smyser, Christopher D; Ahmed, Sarah; Carter, Melissa; Barnett, Sarah; Hufnagel, Robert B; Goldstein, Amy; Narumi-Kishimoto, Yoko; Olds, Carissa; Collins, Sarah; Johnston, Kathreen; Deleuze, Jean-François; Nitschké, Patrick; Friend, Kathryn; Harris, Catharine; Goetsch, Allison; Martin, Beth; Boyle, Evan August; Parrini, Elena; Mei, Davide; Tattini, Lorenzo; Slavotinek, Anne; Blair, Ed; Barnett, Christopher; Shendure, Jay; Chelly, Jamel; Dobyns, William B; Guerrini, Renzo

2015-12-01

Bilateral perisylvian polymicrogyria (BPP), the most common form of regional polymicrogyria, causes the congenital bilateral perisylvian syndrome, featuring oromotor dysfunction, cognitive impairment, and epilepsy. The causes of BPP are heterogeneous, but only a few genetic causes have been reported. The aim of this study was to identify additional genetic causes of BPP and characterise their frequency in this population. Children (aged ≤18 years) with polymicrogyria were enrolled into our research programme from July, 1980, to October, 2015, at two centres (Florence, Italy, and Seattle, WA, USA). We obtained samples (blood and saliva) throughout this period at both centres and did whole-exome sequencing on DNA from eight trios (two parents and one affected child) with BPP in 2014. After the identification of mosaic PIK3R2 mutations in two of these eight children, we performed targeted screening of PIK3R2 by two methods in a cohort of 118 children with BPP. First, we performed targeted sequencing of the entire PIK3R2 gene by single molecule molecular inversion probes (smMIPs) on 38 patients with BPP with normal to large head size. Second, we did amplicon sequencing of the recurrent PIK3R2 mutation (Gly373Arg) in 80 children with various types of polymicrogyria including BPP. One additional patient had clinical whole-exome sequencing done independently, and was included in this study because of the phenotypic similarity to our cohort. We identified a mosaic mutation (Gly373Arg) in a regulatory subunit of the PI3K-AKT-mTOR pathway, PIK3R2, in two children with BPP. Of the 38 patients with BPP and normal to large head size who underwent targeted next-generation sequencing by smMIPs, we identified constitutional and mosaic PIK3R2 mutations in 17 additional children. In parallel, one patient had the recurrent PIK3R2 mutation identified by clinical whole-exome sequencing. Seven of these 20 patients had BPP alone, and 13 had BPP in association with features of the

Activating cysteinyl leukotriene receptor 2 (CYSLTR2) mutations in blue nevi

PubMed Central

Möller, Inga; Murali, Rajmohan; Müller, Hansgeorg; Wiesner, Thomas; Jackett, Louise A; Scholz, Simone L; Cosgarea, Ioana; van de Nes, Johannes AP; Sucker, Antje; Hillen, Uwe; Schilling, Bastian; Paschen, Annette; Kutzner, Heinz; Rütten, Arno; Böckers, Martin; Scolyer, Richard A; Schadendorf, Dirk; Griewank, Klaus G

2017-01-01

Blue nevi are common melanocytic tumors arising in the dermal layer of the skin. Similar to uveal melanomas, blue nevi frequently harbor GNAQ and GNA11 mutations. Recently, recurrent CYSLTR2 and PLCB4 mutations were identified in uveal melanomas not harboring GNAQ or GNA11 mutations. All four genes (GNAQ, GNA11, CYSLTR2, and PLCB4) code for proteins involved in the same signaling pathway, which is activated by mutations in these genes. Given the related functional consequences of these mutations and the known genetic similarities between uveal melanoma and blue nevi, we analyzed a cohort of blue nevi to investigate whether CYSLTR2 and PLCB4 mutations occur in tumors lacking GNAQ or GNA11 mutations (as in uveal melanoma). A targeted next-generation sequencing assay covering known activating mutations in GNAQ, GNA11, CYSLTR2, PLCB4, KIT, NRAS, and BRAF was applied to 103 blue nevi. As previously reported, most blue nevi were found to harbor activating mutations in GNAQ (59%, n = 61), followed by less frequent mutations in GNA11 (16%, n = 17). Additionally, one BRAF (1%) and three NRAS (3%) mutations were detected. In three tumors (3%) harboring none of the aforementioned gene alterations, CYSLTR2 mutations were identified. All three CYSLTR2 mutations were the same c.386T > A, L129Q mutation previously identified in uveal melanoma that has been shown to lead to increased receptor activation and signaling. In summary, our study identifies CYSLTR2 L129Q alterations as a previously unrecognized activating mutation in blue nevi, occuring in a mutually exclusive fashion with known GNAQ and GNA11 mutations. Similar to GNAQ and GNA11 mutations, CYSLTR2 mutations, when present, are likely defining pathogenetic events in blue nevi. PMID:27934878

Activating cysteinyl leukotriene receptor 2 (CYSLTR2) mutations in blue nevi.

PubMed

Möller, Inga; Murali, Rajmohan; Müller, Hansgeorg; Wiesner, Thomas; Jackett, Louise A; Scholz, Simone L; Cosgarea, Ioana; van de Nes, Johannes Ap; Sucker, Antje; Hillen, Uwe; Schilling, Bastian; Paschen, Annette; Kutzner, Heinz; Rütten, Arno; Böckers, Martin; Scolyer, Richard A; Schadendorf, Dirk; Griewank, Klaus G

2017-03-01

Blue nevi are common melanocytic tumors arising in the dermal layer of the skin. Similar to uveal melanomas, blue nevi frequently harbor GNAQ and GNA11 mutations. Recently, recurrent CYSLTR2 and PLCB4 mutations were identified in uveal melanomas not harboring GNAQ or GNA11 mutations. All four genes (GNAQ, GNA11, CYSLTR2, and PLCB4) code for proteins involved in the same signaling pathway, which is activated by mutations in these genes. Given the related functional consequences of these mutations and the known genetic similarities between uveal melanoma and blue nevi, we analyzed a cohort of blue nevi to investigate whether CYSLTR2 and PLCB4 mutations occur in tumors lacking GNAQ or GNA11 mutations (as in uveal melanoma). A targeted next-generation sequencing assay covering known activating mutations in GNAQ, GNA11, CYSLTR2, PLCB4, KIT, NRAS, and BRAF was applied to 103 blue nevi. As previously reported, most blue nevi were found to harbor activating mutations in GNAQ (59%, n=61), followed by less frequent mutations in GNA11 (16%, n=17). Additionally, one BRAF (1%) and three NRAS (3%) mutations were detected. In three tumors (3%) harboring none of the aforementioned gene alterations, CYSLTR2 mutations were identified. All three CYSLTR2 mutations were the same c.386T>A, L129Q mutation previously identified in uveal melanoma that has been shown to lead to increased receptor activation and signaling. In summary, our study identifies CYSLTR2 L129Q alterations as a previously unrecognized activating mutation in blue nevi, occuring in a mutually exclusive fashion with known GNAQ and GNA11 mutations. Similar to GNAQ and GNA11 mutations, CYSLTR2 mutations, when present, are likely defining pathogenetic events in blue nevi.

Genome-first approach diagnosed Cabezas syndrome via novel CUL4B mutation detection.

PubMed

Okamoto, Nobuhiko; Watanabe, Miki; Naruto, Takuya; Matsuda, Keiko; Kohmoto, Tomohiro; Saito, Masako; Masuda, Kiyoshi; Imoto, Issei

2017-01-01

Cabezas syndrome is a syndromic form of X-linked intellectual disability primarily characterized by a short stature, hypogonadism and abnormal gait, with other variable features resulting from mutations in the CUL4B gene. Here, we report a clinically undiagnosed 5-year-old male with severe intellectual disability. A genome-first approach using targeted exome sequencing identified a novel nonsense mutation [NM_003588.3:c.2698G>T, p.(Glu900*)] in the last coding exon of CUL4B , thus diagnosing this patient with Cabezas syndrome.

Targeted mutagenesis of aryl hydrocarbon receptor 2a and 2b genes in Atlantic killifish (Fundulus heteroclitus)

PubMed Central

Aluru, Neelakanteswar; Karchner, Sibel I.; Franks, Diana G.; Nacci, Diane; Champlin, Denise; Hahn, Mark E.

2014-01-01

Understanding molecular mechanisms of toxicity is facilitated by experimental manipulations, such as disruption of function by gene targeting, that are especially challenging in non-standard model species with limited genomic resources. While loss-of-function approaches have included gene knock-down using morpholino-modified oligonucleotides and random mutagenesis using mutagens or retroviruses, more recent approaches include targeted mutagenesis using zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 technology. These latter methods provide more accessible opportunities to explore gene function in non-traditional model species. To facilitate evaluations of toxic mechanisms for important categories of aryl hydrocarbon pollutants, whose actions are known to be receptor mediated, we used ZFN and CRISPR-Cas9 approaches to generate aryl hydrocarbon receptor 2a (AHR2a) and AHR2b gene mutations in Atlantic killifish (Fundulus heteroclitus) embryos. This killifish is a particularly valuble non-traditional model for this study, with multiple paralogs of AHR whose functions are not well characterized. In addition, some populations of this species have evolved resistance to toxicants such as halogenated aromatic hydrocarbons. AHR-null killifish will be valuable for characterizing the role of the individual AHR paralogs in evolved resistance, as well as in normal development. We first used five-finger ZFNs targeting exons 1 and 3 of AHR2a. Subsequently, CRISPR-Cas9 guide RNAs were designed to target regions in exon 2 and 3 of AHR2a and AHR2b. We successfully induced frameshift mutations in AHR2a exon 3 with ZFN and CRISPR-Cas9 guide RNAs, with mutation frequencies of 10% and 16%, respectively. In AHR2b, mutations were induced using CRISPR-Cas9 guide RNAs targeting sites in both exon 2 (17%) and exon 3 (63%). We screened AHR2b exon 2 CRISPR-Cas9-injected embryos for

CYP2R1 mutations causing vitamin D-deficiency rickets.

PubMed

Thacher, Tom D; Levine, Michael A

2017-10-01

CYP2R1 is the principal hepatic 25-hydroxylase responsible for the hydroxylation of parent vitamin D to 25-hydroxyvitamin D [25(OH)D]. Serum concentrations of 25(OH)D reflect vitamin D status, because 25(OH)D is the major circulating metabolite of vitamin D. The 1α-hydroxylation of 25(OH)D in the kidney by CYP27B1 generates the fully active vitamin D metabolite, 1,25-dihydroxyvitamin D (1,25(OH) 2 D). The human CYP2R1 gene, located at 11p15.2, has five exons, coding for an enzyme with 501 amino acids. In Cyp2r1-/- knockout mice, serum 25(OH)D levels were reduced by more than 50% compared wild-type mice. Genetic polymorphisms of CYP2R1 account for some of the individual variability of circulating 25(OH)D values in the population. We review the evidence that inactivating mutations in CYP2R1 can lead to a novel form of vitamin D-deficiency rickets resulting from impaired 25-hydroxylation of vitamin D. We sequenced the promoter, exons and intron-exon flanking regions of the CYP2R1 gene in members of 12 Nigerian families with rickets in more than one family member. We found missense mutations (L99P and K242N) in affected members of 2 of 12 families. The L99P mutation had previously been reported as a homozygous defect in an unrelated child of Nigerian origin with rickets. In silico analyses predicted impaired CYP2R1 folding or reduced interaction with substrate vitamin D by L99P and K242N mutations, respectively. In vitro studies of the mutant CYP2R1 proteins in HEK293 cells confirmed normal expression levels but completely absent or markedly reduced 25-hydroxylase activity by the L99P and K242N mutations, respectively. Heterozygous subjects had more moderate biochemical and clinical features of vitamin D deficiency than homozygous subjects. After an oral bolus dose of 50,000 IU of vitamin D 2 or vitamin D 3 , heterozygous subjects had lower increases in serum 25(OH)D than control subjects, and homozygous subjects had minimal increases, supporting a semidominant

The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development

PubMed Central

Ortega-Molina, Ana; Boss, Isaac W.; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W.; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A.; Gascoyne, Randy D.; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M.; Wendel, Hans-Guido

2015-01-01

The lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL). However, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center (GC) involution, impedes B cell differentiation and class switch recombination (CSR). Integrative genomic analyses indicate that KMT2D affects H3K4 methylation and expression of a specific set of genes including those in the CD40, JAK-STAT, Toll-like receptor, and B cell receptor pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3, and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell activating pathways. PMID:26366710

PIK3CA oncogenic mutations represent a major mechanism of resistance to trastuzumab in HER2/neu overexpressing uterine serous carcinomas

PubMed Central

Black, Jonathan D; Lopez, Salvatore; Cocco, Emiliano; Bellone, Stefania; Altwerger, Gary; Schwab, Carlton L; English, Diana P; Bonazzoli, Elena; Predolini, Federica; Ferrari, Francesca; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Santin, Alessandro D

2015-01-01

Objectives: We evaluated the role of PIK3CA-mutations as mechanism of resistance to trastuzumab in primary HER2/neu-amplified uterine-serous-carcinoma (USC) cell lines. Methods: Fifteen whole-exome-sequenced USC cell lines were tested for HER2/neu-amplification and PIK3CA-mutations. Four HER2/neu-amplified USC (2-harbouring wild-type-PIK3CA-genes and 2-harbouring oncogenic-PIK3CA-mutations) were evaluated in in vitro dose-titration-proliferation-assays, cell-viability and HER2 and S6-protein-phosphorylation after exposure to trastuzumab. USC harbouring wild-type-PIK3CA were transfected with plasmids encoding oncogenic PIK3CA-mutations (i.e., H1047R/R93Q) and exposed to trastuzumab. Finally, trastuzumab efficacy was tested by using two USC xenograft mouse models. Results: Seven out of fifteen (46%) of the USC cell lines were HER2/neu-amplified by fluorescence in situ hybridisation. Within these tumours four out of seven (57%) were found to harbour oncogenic PIK3CA-mutations vs two out of eight (25%) of the HER2/neu not amplified cell lines (P=0.01). HER2/neu-amplified/PIK3CA-mutated USC were highly resistant to trastuzumab when compared with HER2/neu-amplified/wild-type-PIK3CA cell lines (P=0.02). HER2/neu-amplified/PIK3CA wild-type cell lines transfected with oncogenic PIK3CA-mutations increased their resistance to trastuzumab (P<0.0001). Trastuzumab was effective in reducing tumour growth (P=0.001) and improved survival (P=0.0001) in mouse xenografts harbouring HER2-amplified/PIK3CA wild-type USC but not in HER2-amplified/PIK3CA-mutated tumours. Conclusions: Oncogenic PIK3CA mutations are common in HER2/neu-amplified USC and may constitute a major mechanism of resistance to trastuzumab treatment. PMID:26325104