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Sample records for dizygotic monochorionic twin

  1. Chimerism of buccal membrane cells in a monochorionic dizygotic twin.

    PubMed

    Fumoto, Seiko; Hosoi, Kenichiro; Ohnishi, Hiroaki; Hoshina, Hiroaki; Yan, Kunimasa; Saji, Hiroh; Oka, Akira

    2014-04-01

    No monochorionic dizygotic twins (MCDZTs) with cellular chimerism involving cells other than blood cells have been reported in the literature to date. Here we report a probable first case of MCDZTs with buccal cell chimerism. A 32-year-old woman conceived twins by in vitro fertilization by using 2 cryopreserved blastocysts that were transferred into her uterus. An ultrasound scan at 8 weeks' gestation showed signs indicative of monochorionic twins. A healthy boy and a healthy girl were born, showing no sexual ambiguity. Cytogenetic analyses and microsatellite studies demonstrated chimerism in blood cells of both twins. Notably, repeated fluorescence in situ hybridization and microsatellite studies revealed chimerism in buccal cells obtained from 1 of the twins. Although the mechanism through which buccal cell chimerism was generated remains to be elucidated, ectopic differentiation of chimeric hematopoietic cells that migrated to the buccal membrane or the cellular transfer between the 2 embryos at the early stage of development might be responsible for the phenomenon. This hypothesis raises an interesting issue regarding embryonic development and cellular differentiation into organs during fetal development. Given the possibility of cryptic chimerism in various organs including gonadal tissues in MCDZTs, close observation will be required to determine whether complications develop in the course of the patients' growth. PMID:24685957

  2. Antenatal Diagnosis of Dizygotic, Monochorionic Twins Following IVF/ICSI

    PubMed Central

    Korsun, P.; Bals-Pratsch, M.; Ortmann, O.; Markus, S.; Germer, U.

    2016-01-01

    Monochorionic twins are usually monozygotic and thus usually have the same sex. A case of monochorionic diamniotic twins following IVF/ICSI and laser treatment of the zona pellucida (“assisted hatching”) is presented in which partial embryo amalgamation appears to have occurred. Discordant sex between the twins was suspected on detailed antenatal ultrasound at 13 + 3 weeks gestation and was confirmed on subsequent examinations. The sexual phenotype at birth was female for one twin and male for the other. Placental histology confirmed the monochorionic, diamniotic situation. Cytogenetic analysis of both twins was carried out postpartum on various tissues. On karyotyping of blood lymphocytes the male and female twins each had one mosaic of male and female cells. Oral mucosal cells showed normal male and female karyotypes respectively. Analysis of urothelium showed a normal result for the male infant, and a weak gonosomal mosaic with an XX and XY constellation for the female infant. At least for blood lymphocytes, a diagnosis of chimerism was proven. PMID:27365544

  3. Dizygotic twins with myelomeningocele.

    PubMed

    Das, Ghanshyam; Aggarwal, Anju; Faridi, M M A

    2003-03-01

    Among the neural tube defects incidence of spinabifida and myelomeningocele is less in twins compared to singletons. This article reports a case of dizygotic twins with myelomeningocele, a rare occurrence. Possible association of twining and neural tube defects and its impact on genetic counseling in such cases has been discussed. PMID:12785300

  4. Uncomplicated monochorionic diamniotic twin pregnancy.

    PubMed

    Nair, M; Kumar, G

    2009-02-01

    There have been significant advances in our understanding of the aetiology and management of disorders specific to Monochorionic Diamniotic (MCDA) twin pregnancies like Twin-Twin Transfusion Syndrome (TTTS) and Twin Reversed Arterial Perfusion (TRAP) but there is paucity of data about the management of uncomplicated MCDA twins pregnancies. It is accepted that even in the absence of specific complications, these pregnancies are associated with increased perinatal morbidity & mortality. The aim of this review is to gather evidence regarding the management of seemingly uncomplicated monochorionic diamniotic pregnancies. PMID:19274536

  5. Twins reunited: scientific and personal perspectives/twin research studies: multiple birth effects on IQ and body size; life style, muscles, and metabolism; monochorionic dizygotic twin with blood chimerism; amniocentesis for twins/twins in the media: identical doctors; freedom fighter for twins; twin scholarships; Auguste and Jean-Felix Piccard; twins born apart.

    PubMed

    Segal, Nancy L; Mulligan, Christy A

    2014-04-01

    A reunion of 38-year-old female monozygotic twins took place in Daegu, South Korea, on January 14, 2014. Scientific and personal perspectives on this extraordinary event are provided. A review of timely twin research follows, covering the effects of multiple births on IQ and body size, lifestyle and physical fitness associations, a rare case of a dizygotic twin with blood chimerism and definitional issues surrounding amniocentesis-related loss in multiple birth pregnancies. Interesting and informative mention of twins in the media includes twin doctors, a twin freedom fighter, the availability of college scholarships for twins, a new book about the Piccard family (two of whose members were twins), and co-twins born before and after the new year. A follow-up to a previous mention of identical twin biatheletes is also provided. PMID:24589452

  6. Neonatal hemochromatosis in monochorionic twins.

    PubMed

    Korkmaz, L; Baştuğ, O; Daar, G; Doğanay, S; Deniz, K; Kurtoğlu, S

    2015-01-01

    Neonatal hemochromatosis (NH) is a form of neonatal liver failure caused by maternal-fetal alloimmune injury to hepatocytes. The etiology of neonatal hemochromatosis is not exactly understood. However, according to one theory neonatal hemochromatosis is believed to be an alloimmune disorder causing liver injury in the fetus. In order to diagnose neonatal hemochromatosis there are some criteria that should be taken into account, such as positive family history, high serum ferritin levels, high serum alpha-fetoprotein levels and siderosis demonstrated by histology or with magnetic resonance.We present a case of a monochorionic newborn twin who applied to our hospital with sepsis clinical symptoms like clinics, was diagnosed with NH and immediately treated with antioxidant therapy while the other twin with same clinical symptoms did not respond to therapy and passed away. NH should be considered in the differential diagnosis of cases with sepsis-like clinical symptoms that do not respond to antibiotics; early antioxidant therapy in these cases is lifesaving. PMID:26836824

  7. Monochorionic twins discordant for mosaic trisomy 14.

    PubMed

    He, Mai; Pepperell, John R; Gundogan, Fusun; De Paepe, Monique E; Maggio, Lindsay; Lu, Shaolei; Kostadinov, Stefan; O'Brien, Barbara; Delamonte, Suzanne; Pinar, Halit; Tantravahi, Umadevi

    2014-05-01

    Monochorionic-diamniotic twins are usually monozygotic twins and known to be associated with adverse obstetric and perinatal outcomes. Cases of discordant karyotype of monozygotic twins are rare and most involves sex chromosomes. We present the first case of monochorionic twins with discordant karyotype manifested as mosaic trisomy 14 in one twin (B) and a normal karyotype in the other (A). We describe the postmortem pathological and imaging findings of the trisomic twin and for the first time neuropathological findings of this entity. Metaphase chromosome analysis of twin B using fetal tissue showed a 47,XX, +14 karyotype. Chromosomal microarray analysis (CMA) using fetal tissue revealed 38% mosaicism. CMA with placental tissue from both sides demonstrated normal karyotype and confirmed monozygosity, highlighting the value of array based testing on diagnosing mosaicism and zygosity. PMID:24458767

  8. Monoamniotic monochorionic twins discordant for noncompaction cardiomyopathy.

    PubMed

    Ng, Dianna; Bouhlal, Yosr; Ursell, Philip C; Shieh, Joseph T C

    2013-06-01

    Occasionally "identical twins" are phenotypically different, raising the question of zygosity and the issue of genetic versus environmental influences during development. We recently noted monochorionic-monoamniotic twins, one of which had an isolated cardiac abnormality, noncompaction cardiomyopathy, a condition characterized by cardiac ventricular hypertrabeculation. We examined the prenatal course and subsequent pathologic correlation since ventricular morphogenesis may depend on early muscular contraction and blood flow. The monochorionic-monoamniotic female twin pair was initially identified since one fetus presented with increased nuchal translucency. Complete heart block was later identified in the fetus with nuchal translucency who did not survive after delivery. In contrast, the unaffected twin had normal cardiac studies both prenatally and postnatally. Pathologic analysis of the affected twin demonstrated noncompaction of the left ventricle with dysplasia of the aortic and pulmonary valves. Dissection of the cardiac conduction system disclosed atrioventricular bundle fibrosis. Maternal lupus studies, amniocentesis with karyotype, and studies for 22q11.2 were normal. To test for zygosity, we performed multiple STR marker analysis and found that all markers were shared even using nonblood tissues from the affected twin. These studies demonstrate that monozygotic twins that are monochorionic monoamniotic can be discordant for cardiac noncompaction. The results suggest further investigation into the potential roles of pathologic fibrosis, contractility, and blood flow in cardiac ventricle development. PMID:23636980

  9. Monochorionic dizygous twins presenting with blood chimerism and discordant sex.

    PubMed

    Smeets, Dominique; van Vugt, John M G; Gomes, Ingrid; van den Heuvel, Simone; van Heijst, Arno; Reuss, Annette; Claahsen-van der Grinten, Hedi L

    2013-08-01

    Monochorionic dizygous twins are probably more frequent than considered previously as many cases remain unrecognized, especially when the children have the same sex. Here we present a pair of dizygous, sex-discordant monochorionic twins who were conceived after artificial insemination. Histological examination of the placenta and extensive genetic studies of the healthy boy and girl clearly proved that they indeed were monochorionic dizygous twins with a fully joined blood circulation. We conclude that when counseling parents expecting monochorionic twins of discordant sex, not only a disorder of sexual differentiation in one of the twins should be addressed but also the possibility of dizygosity with a completely normal (sexual) development of both children. PMID:23769301

  10. Genetic modelling of dizygotic twinning in pedigrees of spontaneous dizygotic twins

    SciTech Connect

    Meulemans, W.J.; Derom, C.A.; Derom, R.M.

    1996-01-22

    The inheritance of spontaneous dizygotic (DZ) twinning was investigated in 1,422 three-generation pedigrees ascertained through mothers of spontaneous DZ proband twins. DZ twinning was modelled as a trait expressed only in women. The penetrance was modelled first as a parity independent and secondly as parity dependent. The observed frequencies of maternal and paternal grandmothers with DZ twins differed significantly from the expectations under an X-linked mode of inheritance. Complex segregation analysis showed that the parity-independent phenotype of {open_quotes}having DZ twins{close_quotes} was consistent with an autosomal monogenic dominant model, with a gene frequency of 0.035 and a female-specific lifetime penetrance of 0.10. Recessive, polygenic, and sporadic models were rejected. The autosomal dominant model revealed a strong robustness against a changing population prevalence and the loss of information due to the presence of same-sexed twin pairs of unknown zygosity. When DZ twinning was modelled as a parity dependent trait, the data were compatible with an autosomal dominant model with a gene frequency of 0.306 and a penetrance of 0.03 per birth for female gene carriers. 19 refs., 5 tabs.

  11. X-inactivation patterns in monozygotic and dizygotic female twins

    SciTech Connect

    Goodship, J.; Carter, J.; Burn, J.

    1996-01-22

    We have tested the hypothesis that contrasting X-inactivation patterns could be a trigger for monozygotic twinning in females. X-inactivation patterns were studied in umbilical cord tissue in 43 monozygotic twin pairs and 24 dizygotic twin pairs. Very skewed or non-random X-inactivation patterns were observed in both twins in six of the monozygotic twin pairs and in one of the dizygotic twin pairs. Contrasting X-inactivation patterns occurred in only one of the six monozygotic twin pairs. This does not support the original hypothesis. There is a trend to extreme skewing of X-inactivation pattern occurring more frequently in monozygotic twins. 21 refs., 1 fig., 2 tabs.

  12. Genetic Factors in the Ontogeny of Spoken Language: Evidence from Monozygotic and Dizygotic Twins.

    ERIC Educational Resources Information Center

    Locke, John L.; Mather, Patricia L.

    1989-01-01

    Analysis of speech samples from four-year-old monozygotic and dizygotic twins revealed that the monozygotic twins were significantly more likely to misproduce the same sound on an articulation test than were dizygotic twins. The dizygotic twins were no more likely to share errors than were children who were both genetically and environmentally…

  13. Maternal serum alpha fetoprotein in monozygotic and dizygotic twin pregnancies.

    PubMed

    Thom, H; Buckland, C M; Campbell, A G; Thompson, B; Farr, V

    1984-01-01

    Maternal serum alpha-fetoprotein (MSAFP) values in the second trimester have been related to pregnancy outcome for 100 normal twin pairs, 42 monozygous (MZ) and 58 dizygous (DZ), liveborn after 28 weeks gestation. The median MSAFP value was 1.9 multiples of the median value (MOM) for uncomplicated singleton pregnancies. Both very low and very high MSAFP values were associated with twins of low birthweight. MSAFP values were higher in MZ than DZ twin pregnancies particularly those with dizygotes of like-sex. This effect was even more marked when only dichorionic like-sex twin pairs were compared. PMID:6209699

  14. Monozygotic VS. Dizygotic Twin Behavior in Artificial Mouse Twins

    PubMed Central

    Baunack, E.; Falk, U.; Gärtner, K.

    1984-01-01

    Adult inbred mice of an isogenic strain (AKR/NHan or C57BL/6J Han) differ in social (sexual and agonistic), emotional and psychomotoric behavior, depending on the kind of manipulation to which they were subjected at an early ontogenetic stage. Monozygotic twins (MZT) from eight-cell stages halved and transferred to uterine foster mothers were compared with dizygotic twins (DZT) from nonreduced but transferred eight-cell stages and with naturally born animals (NBA). Generally, early embryonic conditions predict the behavioral characteristics of the adult animals to a high degree. The MZT are motorially less active, less emotional, less aggressive and less socially interested than DZT and NBA. In tests of spontaneous social behavior (allogrooming, anogenital licking, mounting, fighting), as well as in tests for emotionality (open field: crossed fields and defecation), these behavioral patterns occurred less frequently in MZT than in DZT; the NBA were mostly intermediate. The copulatory pattern of male MZT differs from that of male DZT by a shortage of intromission latency and duration; furthermore, MZT pairs do not build up a steady rank order in competitive copulation tests, as opposed to DZT and NBA pairs. In a test for psychomotoric behavior (swimming), the MZT prefer "floating" as a survival strategy, wheras the DZT and NBA prefer "adult swimming." Therefore, it can be concluded that these behavioral differences may be caused by the particular psychosocial environment in which the twins grow up or may be due to early prenatal peculiarities, such as inadequate synchronization of the developmental status of uterus and embryo. PMID:6538528

  15. Neonatal morbidity in growth-discordant monochorionic twins: comparison between the larger and the smaller twin.

    PubMed

    Lopriore, Enrico; Sluimers, Carolien; Pasman, Suzanne A; Middeldorp, Johanna M; Oepkes, Dick; Walther, Frans J

    2012-08-01

    Fetal growth restriction in singletons has been shown to enhance fetal lung maturation and reduce the risk of respiratory distress syndrome due to increased endogenous steroid production. However, data on lung maturation in growth-discordant monochorionic (thus, identical) twins are lacking. Our objective was to compare the risk of severe neonatal morbidity between the larger and the smaller twin in monochorionic twins with birth weight discordance (BWD). We included in the study all consecutive monochorionic diamniotic pregnancies with severe BWD (≥25%) and two live-born twins delivered at our center (n=47 twin pairs). We compared the incidence of neonatal morbidity, particularly respiratory distress syndrome (RDS), and cerebral lesions between the larger and the smaller co-twin. The incidence of severe neonatal morbidity in the larger and smaller twin was 38% (18/47) and 19% (9/47), respectively (odds ratio (OR) 2.66, 95% confidence interval (CI) 0.94-7.44) and was due primarily to the higher incidence of RDS, 32% (15/47) and 6% (3/47), respectively (OR 6.88, 95% CI 1.66-32.83). In conclusion, this study shows that the larger twin in monochorionic twin pairs with BWD is at increased risk of severe neonatal morbidity, particularly RDS, compared to the smaller twin. PMID:22854118

  16. Monochorionic versus dichorionic twins: Are obstetric outcomes always different?

    PubMed

    Coutinho Nunes, Filipa; Domingues, Ana Patrícia; Vide Tavares, Mariana; Belo, Adriana; Ferreira, Cristina; Fonseca, Etelvina; Moura, Paulo

    2016-07-01

    This prospective cohort study compared obstetric, perinatal and postpartum outcomes of monochorionic diamniotic (n = 228) versus (vs.) dichorionic (n = 598) twin pregnancies. Statistical analysis was performed using software SPSS® v19.0.0.2. Chi square, Fischer's exact, Student's t and Mann-Withney tests were applied. Obstetrical complications rates were 85.5% vs. 75.1% (p < 0.01). Differences were found in preterm premature rupture of membranes (26.3% vs. 19.3%, p < 0.05) and intrauterine growth restriction (19.7% vs. 10.5%, p < 0.01). Twin-to-twin transfusion syndrome (TTTS) occurred in 7.9% of monochorionic pregnancies. Vaginal delivery occurred in 47.4% vs. 43.1%. Monochorionic pregnancies had earlier gestational ages at delivery and subsequently lower birthweights (p < 0.01). There was no difference in Apgar scores. Admission rate of at least one of the newborns in intensive care unit (NICU) was 50% vs. 38.9% (p < 0.05). Postpartum complications were similar. These results were the same excluding TTTS cases, except for admission in NICU (46.8% vs. 34.9%, p > 0.05). Analysing only the uncomplicated pregnancies (33 vs. 149), there were no differences in perinatal outcomes. We conclude that monochorionic pregnancies had higher rates of obstetrical complications, which were independent of TTTS occurrence in our sample. However, considering only the uncomplicated pregnancies till delivery, there were no significant differences in perinatal outcomes. PMID:27013084

  17. Specific complications of monochorionic twin pregnancies: twin-twin transfusion syndrome and twin reversed arterial perfusion sequence.

    PubMed

    Chalouhi, G E; Stirnemann, J J; Salomon, L J; Essaoui, M; Quibel, T; Ville, Y

    2010-12-01

    Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins. This unequal placental sharing can cause complications including twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence (TAPS), selective intrauterine growth restriction or twin reversed arterial perfusion sequence (TRAP). Monochorionicity also makes the management of these specific complications as well as that of a severe malformation in one twin hazardous since the spontaneous death of one twin exposes the co-twin to a risk of exsanguination into the dead twin and its placenta. The latter is responsible for the death of the co-twin in up to 20% of the cases and in ischemic sequelae in about the same proportions in the survivors. Although the symptoms of all these complications are very different, the keystone of their management comes down to either surgical destruction of the inter-twin anastomoses on the chorionic plate when aiming at dual survival or selective and permanent occlusion of the cord of a severely affected twin aiming at protecting the normal co-twin. This can be best achieved by fetoscopic selective laser coagulation and bipolar forceps cord coagulation respectively. PMID:20855238

  18. NOTE: Trends of discordant fetal growth in monochorionic twin pregnancies

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; Umur, Asli

    2000-08-01

    We derived simple analytical relations representing trends of discordant fetal growth in monochorionic twins developing the twin-twin transfusion syndrome from an approximation of previously developed model equations. In severe twin-twin transfusion syndrome cases, the difference between the estimated fetal weights of both twins increases proportional to (t-5)5 (t denotes gestational age in weeks) and the sum of both weights increases proportional to t3. Hence, the ratio between the difference of estimated fetal weights and the average of the two weights (difference average ratio) increases in proportion to (t-5)5/t3. In mild cases, the difference between estimated fetal weights as well as the sum of the two weights increases proportional to t3. Therefore, the difference average ratio becomes a constant. Comparison with clinical data of severe and mild cases showed surprisingly good agreement except after laser coagulation of placental anastomoses. These relations may therefore enable us to distinguish between severe and mild developing twin-twin transfusion syndrome cases.

  19. NOTE: Polyhydramnios and arterio-arterial placental anastomoses may beneficially affect monochorionic twin pregnancies

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; Kranenburg-Lakeman, Phillis; Milovanovic, Zeljko; Vergroesen, Isabelle; Boer, Kees

    2001-03-01

    Our objective was to appraise whether an increased amniotic fluid pressure by polyhydramnios can beneficially affect monochorionic twins that are haemodynamically connected by arterio-venous plus arterio-arterial placental anastomoses. We assessed the effects of polyhydramnios in monochorionic twin placentas, combining (a) data from previous in vitro placental perfusion experiments in singleton term placentas under simulated normal and increased amniotic fluid pressures with (b) logical deduction from observations made in monochorionic twins. Our hypothesis is that in monochorionic placentas, an increased amniotic fluid pressure increases the placental microvascular resistance but not the resistance of placental chorionic plate arteries. Hence, an increased amniotic fluid pressure increases the microvascular resistance of the joint cotyledon, the arterio-venous resistance, but not the arterio-arterial resistance. This proposed mechanism reduces arterio-venous but not oppositely directed arterio-arterial transfusion. Therefore, reversal of the normal direction of net foeto-foetal transfusion may develop, which will reduce the circulatory imbalance that evolved between the monochorionic foetal twins. In contrast, in monochorionic twins connected by unidirectional or bidirectional arterio-venous anastomoses reversal of the normal direction of net foeto-foetal transfusion will not occur. In conclusion, reversal of the normal direction of net foeto-foetal transfusion, induced by polyhydramnios, is protective against the onset and severity of twin-twin transfusion syndrome in monochorionic twins connected by arterio-venous plus arterio-arterial anastomoses, but not by unidirectional or bidirectional arterio-venous anastomoses.

  20. NOTE: Haemodynamic resistance model of monochorionic twin pregnancies complicated by acardiac twinning

    NASA Astrophysics Data System (ADS)

    Umur, Asli; van Gemert, Martin J. C.; van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; Nikkels, Peter G. J.

    2004-07-01

    An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauterine or neonatally in about 50% of the cases due to congestive heart failure, polyhydramnios and prematurity. Because the pathophysiology of this pregnancy is currently incompletely understood, we modified our previous haemodynamic model of monochorionic twins connected by placental vascular anastomoses to include the analysis of acardiac twin pregnancies. We incorporated the fetoplacental circulation as a resistance circuit and used the fetal umbilical flow that perfuses the body to define fetal growth, rather than the placental flow as done previously. Using this modified model, we predicted that the pump twin has excess blood volume and increased mean arterial blood pressure compared to those in the acardiac twin. Placental perfusion of the acardiac twin is significantly reduced compared to normal, as a consequence of an increased venous pressure, possibly implying reduced acardiac placental growth. In conclusion, the haemodynamic analysis may contribute to an increased knowledge of the pathophysiologic consequences of an acardiac body mass for the pump twin.

  1. Prenatal diagnosis of Down syndrome in dizygotic twin pregnancy.

    PubMed

    Krawczyk, Józef; Borowski, Dariusz; Wegrzyn, Piotr; Drews, Krzysztof; Wielgoś, Mirosław

    2013-11-01

    We present a case of a 33-year-old pregnant woman who had a transvaginal ultrasound performed at week 9 of gestation. A dichorionic diamniotic twin pregnancy with symmetrically developing fetuses, was confirmed. Chromosomal defect markers (NT NB, DV TV) were analyzed in the first genetic test, performed according to the Fetal Medicine Foundation (FMF) criteria, and the double marker test was performed (PAPP-A protein and free beta-hCG concentrations in patient serum were determined). In the subsequent diagnostic procedures, the patient was offered and consented to amniopuncture after week 15 of gestation. The material obtained in the course of that invasive procedure allowed to identify a normal male karyotype - 46, XY in the first fetus (Fetus I). Cytogenetic analysis of the material from the second fetus (Fetus II) resulted in the diagnosis of an abnormal female karyotype - 47, XX, +21. Based on the analyzed clinical case, we present the difficulties of performing prenatal diagnosis in a dizygotic twin pregnancy The results prove the applicability and efficacy of prenatal diagnostics tests based on the FMF criteria also in twin pregnancies. PMID:24455857

  2. Similarity of Monozygotic and Dizygotic Twins in Level and Lability of Subclinically Depressed Mood.

    ERIC Educational Resources Information Center

    Wierzbicki, Michael

    1986-01-01

    Ninety-two adult twin-pairs were recruited. Twin zygosity was determined by self-report inventory. Monozygotic twins resembled one another more than dizygotic twins in most measures of both level and lability of mood, which provides modest evidence for a genetic influence on subclinical levels of depression. (Author/ABB)

  3. NOTE: Modelling the influence of amnionicity on the severity of twin twin transfusion syndrome in monochorionic twin pregnancies

    NASA Astrophysics Data System (ADS)

    van den Wijngaard, Jeroen P. H. M.; Umur, Asli; Ross, Michael G.; van Gemert, Martin J. C.

    2004-03-01

    Clinical treatment for diamniotic monochorionic twin twin transfusion syndrome (TTTS) may include conversion of diamniotic pregnancies to a monoamniotic monochorionic state by disrupting the amnion septum. We sought to test the underlying hypothesis, i.e. that a monoamniotic state reduces the severity of TTTS. With use of our previously developed mathematical model of two equal fetoplacental circulatory units connected by various sizes and types of placental anastomoses, we compared the haemodynamic and amniotic fluid dynamics of monoamniotic and diamniotic twins that develop TTTS. We used three anastomotic patterns that produce severe, moderate or mild forms of TTTS, respectively, in our diamniotic monochorionic twin model. Monoamnionicity was modelled by adding the two amniotic fluid volumes and using the volume-averaged amniotic fluid osmolality. The results were as follows: for severe TTTS, small differences develop between diamniotic and monoamniotic donor twins in fetal urine production, swallowed volume, blood volume, blood pressures, net fetofetal transfusion, and blood and amniotic fluid osmolality. However, the circulatory imbalance between the monoamniotic twins deteriorates similar to that of diamniotic twins. The pathophysiological differences tend to disappear for milder TTTS. In conclusion, our model suggests that the uncommon finding of TTTS in monoamniotic twins is not due to the presence of a single amniotic sac. Rather, clinically significant differences in anastomotic patterns and the delayed or lack of identification of manifestations in monoamniotic twins account for the reduced rate of TTTS diagnosis. Based on these results we expect the clinical disruption of the amnion septum in diamniotic monochorionic TTTS pregnancies to have only minimal benefits.

  4. Single Fetal Demise at 10 - 14 Weeks of Monochorionic and Dichorionic Twin Pregnancy

    PubMed Central

    Suzuki, Shunji

    2016-01-01

    Background We examined the perinatal outcomes in cases of at least one fetal demise in monochorionic and diamniotic twin pregnancies. Methods We reviewed the obstetric records of all Japanese twin pregnancies managed beyond 9 weeks’ gestation at Japanese Red Cross Katsushika Maternity Hospital between 2008 and 2014. Results The incidence in the monochorionic twin pregnancies was significantly higher than that in the dichorionic twin pregnancies (8.3% vs. 2.6%, odds ratio: 3.40, 95% confidence interval: 1.5 - 7.6, P < 0.01). Of these, 60.0% were diagnosed as fetal demise of both fetuses at the same time (vs. dichorionic twin pregnancy: odds ratio: 12.0, 95% confidence interval: 1.3 - 120, P = 0.04). The rate of “vanishing twin” in cases of at least one fetal demise at 10 - 14 weeks’ gestation in the monochorionic twin pregnancies was significantly lower than that in the diamniotic twin pregnancies (30.0% vs. 88.9%, odds ratio: 0.05, 95% confidence interval: 0.01 - 0.53, P = 0.01). Conclusion The incidence of fetal demise and the influence on the co-twin in monochorionic twin pregnancy is greater than those in dichorionic twin pregnancy. PMID:26985254

  5. Congenital familial myasthenic syndromes: disease and course in an affected dizygotic twin pair

    PubMed Central

    Pavone, Piero; Praticò, Andrea Domenico; Pavone, Vito; Falsaperla, Raffaele

    2013-01-01

    The present report describes clinical variability in an affected dizygotic twin pair. Twin 1 showed classical features of the congenital myasthenic syndromes (CMS), that is, ptosis, dysphonia, asthenia and hypotonia. In twin 2, these clinical signs were less pronounced, but subtle resulting in severe lumbar hyperlordosis. Molecular analysis, performed for both twins, revealed the presence of three polymorphisms in the heterozygous form in RAPSN gene. The present report highlights the clinical variability of the CMS. PMID:23365176

  6. Conjoined twins in a monochorionic triplet pregnancy after in vitro fertilization: a case report

    PubMed Central

    Talebian, Marzieh; Rahimi-Sharbaf, Fatemeh; Shirazi, Mahboobeh; Teimoori, Batool; Izadi-mood, Narges; Sarmadi, Soheila

    2015-01-01

    Background: Monozygotic monochorionic triplet pregnancy with conjoined twins is a very rare condition and is associated with many complications. Case: In this study, we describe a monochorionic–diamniotic triplet pregnancy after in vitro fertilization with an intracytoplasmic sperm injection. At a gestational age of 6 weeks and 4 days of pregnancy one gestational sac was observed, and at a gestational age of 12 weeks and 2 days, triplets with conjoined twins were diagnosed. After consulting with the parents, they chose fetal reduction of the conjoined twins. Selective feticide was successfully performed by radiofrequency ablation at 16 weeks of pregnancy. Unfortunately, the day after the procedure, the membrane ruptured, and 1 week later, all fetuses and placenta were spontaneously aborted. Conclusion: Monochorionic triplet pregnancy with conjoined twins is very rare. These pregnancies are associated with very serious complications. Intra cytoplasmic sperm injection increases the rate of monozygotic twinning and conjoined twins. Counseling with parents before IVF is very important. PMID:26730249

  7. [Prenatal diagnosis of five cases of monochorionic-diamniotic twins discordant for karyotype analysis].

    PubMed

    Wu, Jianzhu; Zhou, Yi; Lin, Shaobin; Chen, Baojiang; Xie, Yingjun

    2015-10-01

    OBJECTIVE To explore the mechanism and diagnostic method for monochorionic-diamniotic twins discordant for karyotype analysis. METHODS Dual amniocentesis was performed on five pairs of monochorionic-diamniotic twins, which all consisted of a normal twin and one with multiple malformations revealed by ultrasound. Karyotype analysis was performed on amniocytes derived from each of the twins. Zygosity was also determined with DNA extracted from amniocytes with 16 polymorphic microsatellite markers. RESULTS Three cases of 45,X, one case of 47,XX,+9 and one case of 47,XY,+18 were detected among the abnormal twins, while the normal fetuses all had a normal karyotype. DNA analysis suggested that, in all cases, the twins have shared the 16 polymorphic microsatellite markers, which confirmed their monozygosity. CONCLUSION Monochorionic-diamniotic twins may be discordant for karyotyping, for which anaphase lagging, chromosomal non-disjunction and trisomy rescue may be the underlying reasons. As a simple method, dual amniocentesis can be used to obtain amniotic fluid samples for karyotype analysis and determination of zygosity for such twins. PMID:26418994

  8. Sib risk and the dizygotic twin concordance rate for multiple sclerosis.

    PubMed Central

    James, W H

    1985-01-01

    Data have been reviewed on sib risk and the dizygotic twin concordance rate in multiple sclerosis. Even when rigorous criteria are applied, the dizygotic twin concordance rate for multiple sclerosis is apparently higher (perhaps 10 times higher) than could be explained by the sib risk. In contrast, twins with Parkinson's disease have low concordance rates even when ascertainment is by informal methods. It is concluded that such methods of ascertainment are not as biased as has been suggested, and that the high concordance rates reported for multiple sclerosis are a characteristic of the disease rather than an artifact of the ascertainment. Three hypotheses are considered which might, in principle, explain this high dizygotic twin concordance rate in multiple sclerosis: 1 One is certainly false, viz, that it is due to an excessive liability of dizygotic twins to the disease. 2 It is possible that a pathogen occurs in early infancy or in pregnancy itself. 3 It seems more likely that the high concordance rate may be explained in terms of age related events or sequences of events. (If such events were pathogenic for one member of a sibship, they would be pathogenic for another only if it were a co-twin). PMID:4039354

  9. High Risk of Unexpected Late Fetal Death in Monochorionic Twins Despite Intensive Ultrasound Surveillance: A Cohort Study

    PubMed Central

    2005-01-01

    Background The rationale for fetal surveillance in monochorionic twin pregnancies is timely intervention to prevent the increased fetal/perinatal morbidity and mortality attributed to twin–twin transfusion syndrome and intrauterine growth restriction. We investigated the residual risk of fetal death after viability in otherwise uncomplicated monochorionic diamniotic twin pregnancies. Methods and Findings We searched an electronic database of 480 completed monochorionic pregnancies that underwent fortnightly ultrasound surveillance in our tertiary referral fetal medicine service between 1992 and 2004. After excluding pregnancies with twin–twin transfusion syndrome, growth restriction, structural abnormalities, or twin reversed arterial perfusion sequence, and monoamniotic and high-order multiple pregnancies, we identified 151 uncomplicated monochorionic diamniotic twin pregnancies with normal growth, normal liquor volume, and normal Doppler studies on fortnightly ultrasound scans. Ten unexpected intrauterine deaths occurred in seven (4.6%) of 151 previously uncomplicated monochorionic diamniotic pregnancies, within 2 wk of a normal scan, at a median gestational age of 34+1 wk (weeks+days; range 28+0 to 36+3). Two of the five cases that underwent autopsy had features suggestive of acute late onset twin–twin transfusion syndrome, but no antenatal indicators of transfusional imbalance or growth restriction, either empirically or in a 1:3 gestation-matched case–control comparison. The prospective risk of unexpected antepartum stillbirth after 32 wk was 1/23 monochorionic diamniotic pregnancies (95% confidence interval 1/11 to 1/63). Conclusion Despite intensive fetal surveillance, structurally normal monochorionic diamniotic twin pregnancies without TTTS or IUGR are complicated by a high rate of unexpected intrauterine death. This prospective risk of fetal death in otherwise uncomplicated monochorionic diamniotic pregnancies after 32 wk of gestation might be

  10. PTX3 genetic variation and dizygotic twinning in The Gambia: could pleiotropy with innate immunity explain common dizygotic twinning in Africa?

    PubMed Central

    Sirugo, Giorgio; Velez Edwards, Digna R.; Ryckman, Kelli K.; Bisseye, Cyrille; White, Marquitta J.; Kebbeh, Bunja; Morris, Gerard A. J.; Adegbola, Richard A.; Tacconelli, Alessandra; Predazzi, Irene; Novelli, Giuseppe; Vannberg, Fredrik O.; Odunsi, Kunle; Page, Grier P.; Williams, Scott M.

    2013-01-01

    Dizygotic (DZ) twinning has a genetic component and is common among sub-Saharan Africans; in The Gambia its frequency is up to 3% of live births. Variation in Pentraxin 3 (PTX3), a soluble pattern recognition receptor that plays an important role both in humoral innate immunity and in female fertility, has been associated with resistance to M. tuberculosis infection and to P. aeruginosa infection in cystic fibrosis patients. We tested whether PTX3 variants in Gambian women associate with DZ twinning, by genotyping five PTX3 single nucleotide polymorphisms (SNPs) in 130 sister pairs (96 full sibs and 34 half sibs) who had DZ twins. We found that two, three and five SNP haplotypes differed in frequency between twinning mothers and those without a history of twinning (from p = 0.006 to 3.03e-06 for two SNP and three SNP haplotypes, respectively). Twinning mothers and West African tuberculosis-controls from a previous study shared several frequent haplotypes. Most importantly, our data are consistent with the previously reported association of PTX3 and female fertility in a West African sample from Ghana. Taken together, these results indicate that selective pressure on PTX3 variants that affect the innate immune response to infectious agents, could also produce the observed high incidence of DZ twinning in Gambians. PMID:22834944

  11. Perinatal Outcomes of Monochorionic-Diamniotic Twin Pregnancies Uncomplicated at 28 Weeks of Gestation

    PubMed Central

    Suzuki, Shunji

    2016-01-01

    We examined the prevalence of specific perinatal complications of monochorionic-diamniotic twin pregnancies in cases without any abnormal findings until the second trimester of pregnancy. This was a retrospective cohort study performed at a tertiary perinatal center in Tokyo, Japan. There were 88 cases of uncomplicated monochorionic-diamniotic twin pregnancies at 28 weeks of gestation. In five of them (5.7%), there were serious complications associated with placental circulatory imbalance between the twins during the third trimester of pregnancy. Two cases were complicated by twin–twin transfusion syndrome, two cases were complicated by twin anemia–polycythemia sequence, and one case was complicated by acute twin–twin transfusion syndrome. In the five cases, no abnormal ultrasonographic findings or symptoms were recognized one or two weeks prior to the diagnosis. Fifty-eight cases (65.9%) were delivered at term uneventfully. Serious complications due to placental circulatory imbalance between twins occurred in about 6% of cases during the third trimester of pregnancy. PMID:27257402

  12. Coincidence of Incomplete Pentalogy of Cantrell and Meningomyelocele in a Dizygotic Twin Pregnancy

    PubMed Central

    Timur, Hakan; Tokmak, Aytekin; Bayram, Hatice; Şükran Çakar, Esra; Danışman, Nuri

    2015-01-01

    Pentalogy of Cantrell is an extremely rare and lethal syndrome. Ectopia cordis is frequently found in fetuses with POC but not required for incomplete forms. Likewise, meningomyelocele is a relatively uncommon neural tube defect affecting central nervous system and associated with neurological problems. Herein, we presented a woman with dizygotic twin pregnancy having coincidence of incomplete POC and MMC in each individual fetus, which has never been reported previously. PMID:26421202

  13. NOTE: Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; van den Wijngaard, Jeroen P. H. M.; Lopriore, Enrico; Pasman, Suzanne A.; Vandenbussche, Frank P. H. A.

    2008-04-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twin fetuses sharing one single (monochorionic) placenta. TTTS is caused by a net inter-twin transfusion of blood through placental anastomoses, from one twin (the donor) to the other (the recipient), which link the two feto-placental circulations. Currently, the only reliable method to measure the net inter-twin transfusion clinically is when incomplete laser therapy of TTTS occurs and one of the twins becomes anemic and requires an intra-uterine transfusion of adult red blood cells. Then, differences between adult hemoglobin concentrations measured during the transfusion and at birth relate not only to the net inter-twin transfusion but also to the finite lifetime of the adult red blood cells. We have analyzed this situation, derived the differential equations of adult hemoglobin in the donor and recipient twins, given the solutions and given expressions relating the net inter-twin flow with clinically measured parameters. We have included single and multiple intra-uterine transfusions. In conclusion, because incomplete laser therapy occurs frequently, and some cases require an intra-uterine transfusion, this method may allow collecting a wealth of net inter-twin flow data from clinicians involved in laser therapy of TTTS. To aid to the widespread use of this method, we have presented the equations as clearly as possible in tables for easy use by others.

  14. Compatibility and conflict: negotiation of relationships by dizygotic same-sex twin girls.

    PubMed

    Danby, Susan; Thorpe, Karen

    2006-02-01

    This article conceptualizes the child as having active agency in the constructions of their social worlds, and reports on a study that understands the twin experiences from the perspectives of the twins. It examines how twins account for their relationships with their co-twins. The study drew on accounts of 60 twin children--10 monozygotic (MZ), 10 dizygotic (DZ) same-sex, 10 DZ opposite-sex pairs--aged 5 to 10 years and their parent (n = 30). The children engaged in a sticker activity in which they represented their friendships, including their friendship with their co-twin. Using the task as a resource, the children were asked about their friends, the attributes of friendship and examples of everyday friendships encounters. These were audio-recorded and transcribed. Further, parents completed a questionnaire that provided demographic information and asked parents about the children's social experiences including twin children's time spent together, shared interests and their co-twin relationship. Using data from the pictorial representation from the sticker task and parent questionnaires, differences in relationship between MZ, DZ same-sex and DZ opposite-sex twins were examined and used to select a smaller sample for detailed study. DZ same-sex twins tended to view their co-twin less favorably and there was a nonsignificant trend in which conflict was elevated, compared to the other two groups. Based on these findings, the transcripts selected for analysis focuses on the DZ same-sex girls. The girls reported that they had differences of thought, activity and self-presentation. Conflict, competition and challenge as types of social interaction were described, suggesting that the everyday relationship of the twin with her co-twin is always being negotiated and realigned. Evident here is the complexity of social interactions in which the twins engaged everyday with each other. PMID:16611475

  15. Suicidal Behaviors in Surviving Monozygotic and Dizygotic Co-Twins: Is the Nature of the Co-Twin's Cause of Death a Factor?

    ERIC Educational Resources Information Center

    Segal, Nancy L.

    2009-01-01

    Genetically informative samples can address hereditary and experiential influences on suicide-related behaviors. The frequency of suicide-related behaviors was compared in twins from two survivor groups: (1) those whose co-twins' deaths were suicides (monozygotic [MZ]: n = 47; dizygotic [DZ]: n = 31), and (2) those whose co-twins' deaths were…

  16. Long-Term Neurodevelopmental Outcome of Monochorionic and Matched Dichorionic Twins

    PubMed Central

    Hack, Karien E. A.; Koopman-Esseboom, Corine; Derks, Jan B.; Elias, Sjoerd G.; de Kleine, Martin J. K.; Baerts, Wim; Go, Attie T. J. I.; Schaap, Arty H. P.; van der Hoeven, Mark A. H. B. M.; Eggink, Alex J.; Sollie, Krystyna M.; Weisglas-Kuperus, Nynke; A.Visser, Gerard H.

    2009-01-01

    Background Monochorionic (MC) twins are at increased risk for perinatal mortality and serious morbidity due to the presence of placental vascular anastomoses. Cerebral injury can be secondary to haemodynamic and hematological disorders during pregnancy (especially twin-to-twin transfusion syndrome (TTTS) or intrauterine co-twin death) or from postnatal injury associated with prematurity and low birth weight, common complications in twin pregnancies. We investigated neurodevelopmental outcome in MC and dichorionic (DC) twins at the age of two years. Methods This was a prospective cohort study. Cerebral palsy (CP) was studied in 182 MC infants and 189 DC infants matched for weight and age at delivery, gender, ethnicity of the mother and study center. After losses to follow-up, 282 of the 366 infants without CP were available to be tested with the Griffiths Mental Developmental Scales at 22 months corrected age, all born between January 2005 and January 2006 in nine perinatal centers in The Netherlands. Due to phenotypic (un)alikeness in mono-or dizygosity, the principal investigator was not blinded to chorionic status; perinatal outcome, with exception of co-twin death, was not known to the examiner. Findings Four out of 182 MC infants had CP (2.2%) - two of the four CP-cases were due to complications specific to MC twin pregnancies (TTTS and co-twin death) and the other two cases of CP were the result of cystic PVL after preterm birth - compared to one sibling of a DC twin (0.5%; OR 4.2, 95% CI 0.5–38.2) of unknown origin. Follow-up rate of neurodevelopmental outcome by Griffith's test was 76%. The majority of 2-year-old twins had normal developmental status. There were no significant differences between MC and DC twins. One MC infant (0.7%) had a developmental delay compared to 6 DC infants (4.2%; OR 0.2, 95% 0.0–1.4). Birth weight discordancy did not influence long-term outcome, though the smaller twin had slightly lower developmental scores than its larger co-twin

  17. [Blood cell chimerism in dizygotic twins conceived by in vitro fertilization].

    PubMed

    Martos-Moreno, G Á; Campos, C; Flores, R; Yturriaga, R; Pérez-Jurado, L A; Argente, J

    2013-10-01

    We present a case of hematopoietic chimerism in dizygotic twins (male and female) conceived by in vitro fertilization (IVF). At 8 years of age a blood karyotype was performed on the female due to the presence of clitoromegaly. Two different lines: 46,XX (53%) and 46,XY (47%) were found. FISH studies confirmed the presence of the SRY gene in 46,XY cells. Karyotyping of the male showed two different lines: 46,XY (58%) and 46,XX (42%). SRY gene was present in 46,XY cells. Microsatellite analyses of blood DNA revealed tetra-allelic contribution at some autosomal loci with similar proportions of maternal and paternal alleles and X/Y chromosome dose. FISH in buccal mucous showed that all cells from the female were 46,XX and those from the male 46,XY. The gonadal karyotype in the female was 46,XX without SRY. Hence, we report 46,XX/46,XY chimerism in dizygotic twins. Blood chimerism was confirmed by performing FISH on the buccal cells of the patients. PMID:23726690

  18. Sirenomelia type VI (sympus apus) in one of dizygotic twins at Chiang Mai University Hospital.

    PubMed

    Nokeaingtong, Kwannapas; Kaewchai, Sirirat; Visrutaratna, Pannee; Khuwuthyakorn, Varangthip

    2015-01-01

    Those born with sirenomelia, a rare congenital anomaly, have features resembling a mermaid. Characteristics of sirenomelia are a single lower limb, sacral and pelvic bone defects, and anorectal and urogenital malformations. There is an increased incidence of sirenomelia in males and twins. This case was a preterm male, dizygotic twin and product of in vitro fertilisation. The baby was born by caesarean section due to breech presentation. He was found to have a fused lower extremity and absent external genitalia and anus. The baby passed away shortly after birth due to severe respiratory failure. Radiographic findings showed small lung volume and pneumothoraces. There were multiple segmental fusions of the vertebrae. Single femur and single tibia were presented in a fused lower limb. Autopsy demonstrated large intestinal atresia, intra-abdominal testes, absence of kidney, ureter and bladder, single umbilical artery, agenesis of blood vessels at lower extremity and agenesis of sacrum and coccyx. PMID:25976191

  19. Correlation between Chronological Age, Dental Age and Skeletal Age among Monozygoyic and Dizygotic Twins

    PubMed Central

    Gupta, Mohit; Divyashree, R; Abhilash, PR; A Bijle, Mohammed Nadeem; Murali, KV

    2013-01-01

    Introduction: Chronological age, dental development, height and weight measurements, sexual maturation characteristics and skeletal age are some biological indicators that have been used to identify time of growth. Many researchers have agreed that skeletal maturity is closely related to the craniofacial growth, and bones of hand and wrist are reliable parameters in assessing it. The complete hand and wrist radiograph involves 30 bones and assessment of these bones is one elaborate task. The present study is therefore, undertaken to assess the correlation between the chronological age, dental age and skeletal ages among different types of twins. Materials and Methods: The study consisted of 60 subjects (30 twins) aged 8 to 16 years, divided into group of 10 monozygotic, 10 dizygotic and 10 mixed sex twins. The sample was selected from Twin Survey- 2008 conducted by Department of Orthodontics and Dentofacial Orthopaedics, Sree Balaji Dental College and Hospital, Chennai. Their zygosity was determined by sex, blood groups and by the parent. The chronological age was measured by the date of birth given by the parents. Panoramic and hand wrist x-rays were taken. Dental age was assessed by Demerjian et al method and skeletal age by Greulich and Pyle method. The correlation among twins in dental and skeletal ages with the chronological age was assessed using Correlation Coefficient and Student's't' Test. Results: The obtained data was fed into the computer and statistical analysis was done for the same using the SPSS version 10.0. Statistical significance was tested at P<0.05 level. Mean and Standard Deviation, Correlation Coefficient, Student's't' Test statistical methods were employed. The result showed highly significant 'p' value as <0.001 in all the correlations except for mixed pairs. Descriptive statistics in most of the areas demonstrated a non-significant result between zygosity groups. Conclusion: There is a correlation existing between the individual

  20. Identification of Common Genetic Variants Influencing Spontaneous Dizygotic Twinning and Female Fertility.

    PubMed

    Mbarek, Hamdi; Steinberg, Stacy; Nyholt, Dale R; Gordon, Scott D; Miller, Michael B; McRae, Allan F; Hottenga, Jouke Jan; Day, Felix R; Willemsen, Gonneke; de Geus, Eco J; Davies, Gareth E; Martin, Hilary C; Penninx, Brenda W; Jansen, Rick; McAloney, Kerrie; Vink, Jacqueline M; Kaprio, Jaakko; Plomin, Robert; Spector, Tim D; Magnusson, Patrik K; Reversade, Bruno; Harris, R Alan; Aagaard, Kjersti; Kristjansson, Ragnar P; Olafsson, Isleifur; Eyjolfsson, Gudmundur Ingi; Sigurdardottir, Olof; Iacono, William G; Lambalk, Cornelis B; Montgomery, Grant W; McGue, Matt; Ong, Ken K; Perry, John R B; Martin, Nicholas G; Stefánsson, Hreinn; Stefánsson, Kari; Boomsma, Dorret I

    2016-05-01

    Spontaneous dizygotic (DZ) twinning occurs in 1%-4% of women, with familial clustering and unknown physiological pathways and genetic origin. DZ twinning might index increased fertility and has distinct health implications for mother and child. We performed a GWAS in 1,980 mothers of spontaneous DZ twins and 12,953 control subjects. Findings were replicated in a large Icelandic cohort and tested for association across a broad range of fertility traits in women. Two SNPs were identified (rs11031006 near FSHB, p = 1.54 × 10(-9), and rs17293443 in SMAD3, p = 1.57 × 10(-8)) and replicated (p = 3 × 10(-3) and p = 1.44 × 10(-4), respectively). Based on ∼90,000 births in Iceland, the risk of a mother delivering twins increased by 18% for each copy of allele rs11031006-G and 9% for rs17293443-C. A higher polygenic risk score (PRS) for DZ twinning, calculated based on the results of the DZ twinning GWAS, was significantly associated with DZ twinning in Iceland (p = 0.001). A higher PRS was also associated with having children (p = 0.01), greater lifetime parity (p = 0.03), and earlier age at first child (p = 0.02). Allele rs11031006-G was associated with higher serum FSH levels, earlier age at menarche, earlier age at first child, higher lifetime parity, lower PCOS risk, and earlier age at menopause. Conversely, rs17293443-C was associated with later age at last child. We identified robust genetic risk variants for DZ twinning: one near FSHB and a second within SMAD3, the product of which plays an important role in gonadal responsiveness to FSH. These loci contribute to crucial aspects of reproductive capacity and health. PMID:27132594

  1. [Simultaneous supraventricular tachycardia in twin premature newborns of a monochorionic pregnancy].

    PubMed

    Chêne, M-A; Parlier, G; Denis, J; Siret, D

    2013-02-01

    Supraventricular tachycardia (SVT) is the most common pediatric arrhythmia. SVT occurs more frequently in infants under 1 year of age, most of whom have structurally normal hearts. Pejorative predisposing factors such as congenital heart disease exist in only a few patients. In patients with a healthy heart, SVT is due to re-entry via an accessory pathway. Some articles describe occurrence of SVT in 1 of the fetuses or newborns from multiple gestation pregnancies, but few cases report simultaneous start of SVT in twins. This observation describes simultaneous occurrence of SVT in both premature infants from a monochorionic twin gestation. Successful emergency treatment consisted in physical maneuvers increasing vagal activity. The twin neonates then received a prolonged anti-arrhythmic amiodarone treatment. Both of their electrocardiograms were normal, without Wolf-Parkinson-White syndrome. Both of their echocardiography results showed aneurysms of the atrial septum. At 6 months of age, SVT had not recurred. This case describes an original presentation of simultaneous SVT in twins and highlights the efficacy of vagal maneuvers to manage stable patients. We discuss the existence of benign predisposing heart structural abnormalities. PMID:23245861

  2. Risk Factors and Relationship of Cutaneous and Uveal Melanocytic Lesions in Monozygotic and Dizygotic Twin Pairs

    PubMed Central

    Varga, Anita; Szabó, Hajnalka; Orvos, Hajnalka; Kemény, Lajos; Oláh, Judit

    2016-01-01

    Background The similar genetic background of a pair of twins, and the similar environmental impacts to which they are exposed allow an exact and objective investigation of various constitutional and environmental factors in naevus development. As far as we are aware, this is the first published survey that simultaneously examines cutaneous and ocular pigmented lesions in an appreciable sample of identical and non-identical twins. Methods 172 pairs of twins of Caucasian origin were included in this study. A whole-body skin examination and a detailed ophthalmological examination were performed to determine the density of melanocytic lesions. A standardized questionnaire was used to assess the data relating to constitutional, sun exposure and other variables. Results A notably high proportion of the subjects (36.78%) manifested one or more clinically atypical melanocytic naevi (CAMNs), and approximately one-third (31.4%) of them at least one benign uveal pigmented lesion (BUPL). The incidence of iris freckles (IFs), iris naevi (INs) and choroidal naevi (CHNs) proved to be 25.35%, 5.98% and 3.52%, respectively. The interclass correlation coefficients for common melanocytic naevi (CMNs), CAMNs, and INs were 0.77, 0.76 and 0.86 in monozygotic twins, as compared with 0.5, 0.27 and 0.25 in dizygotic twin pairs, respectively. A statistically significant correlation was found between the prevalence of CAMNs and that of INs. Conclusions This significant correlation suggests the existence of a subgroup of Caucasian people with an increased susceptibility to both cutaneous and ocular naevus formation. There is accumulating evidence that, besides the presence of cutaneous atypical naevi, INs can serve as a marker of a predisposed phenotype at risk of uveal melanoma. The correlation between cutaneous and ocular pigmented lesions underlines the need for the adequate ophthalmological screening of subjects with CAMNs and INs. PMID:27486750

  3. Double fatal outcome after ruptured vasa previa in monochorionic twins: case report and review of the literature.

    PubMed

    van Steenis, A; Zhao, D P; Steggerda, S J; Kist, W J; Haak, M C; Oepkes, D; Lopriore, Enrico

    2016-08-01

    Vasa previa is a condition in which one or more fetal blood vessels run through the amniotic membranes and cross or run near the external orifice of the uterus. Rupture of membranes can lead to tearing of these vessels and cause acute fetal exsanguination. In monochorionic twin (MC) pregnancies, acute exsanguination in one twin can lead to severe complications in the co-twin due to the presence of inter-twin placental vascular connections. We report a MC pair with severe perinatal asphyxia due to acute exsanguination after prenatally undetected ruptured vasa previa. This resulted in severe hemorrhagic shock in both twins with double fatal outcome. Antenatal detection of vasa previa is of paramount importance to prevent severe morbidity and mortality, especially in MCs. A review of the literature is presented. PMID:26366672

  4. Monozygotic and Dizygotic Twins: A Comparative Analysis of Mental Ability Profiles.

    ERIC Educational Resources Information Center

    Segal, Nancy L.

    1985-01-01

    Among a group of 103 children with a mean age of eight years, full-scale IQ correlation was significantly higher for monozygotic than dizygotic pairs. Monozygotic pairs also showed significantly greater concordance for subtest profile than dizygotic pairs. The usefulness of profile analysis is examined, and directions for future research are…

  5. Population based study of prevalence of islet cell autoantibodies in monozygotic and dizygotic Danish twin pairs with insulin dependent diabetes mellitus.

    PubMed Central

    Petersen, J. S.; Kyvik, K. O.; Bingley, P. J.; Gale, E. A.; Green, A.; Dyrberg, T.; Beck-Nielsen, H.

    1997-01-01

    OBJECTIVE: To study the comparative importance of environment and genes in the development of islet cell autoimmunity associated with insulin dependent diabetes mellitus. DESIGN: Population based study of diabetic twins. SETTING: Danish population. SUBJECTS: 18 monozygotic and 36 dizygotic twin pairs with one or both partners having insulin dependent diabetes. MAIN OUTCOME MEASURES: Presence of islet cell antibodies, insulin autoantibodies, and autoantibodies to glutamic acid decarboxylase (GAD65) in serum samples from twin pairs 10 years (range 0-30 years) and 9.5 years (2-30 years) after onset of disease. RESULTS: In those with diabetes the prevalence of islet cell antibodies, insulin autoantibodies, and autoantibodies to glutamic acid decarboxylase in the 26 monozygotic twins was 38%, 85%, and 92%, respectively, and in the dizygotic twins was 57%, 70%, and 57%, respectively. In those without diabetes the proportions were 20%, 50%, and 40% in the 10 monozygotic twins and 26%, 49%, and 40% in the 35 dizygotic twins. CONCLUSION: There is no difference between the prevalence of islet cell autoantibodies in dizygotic and monozygotic twins without diabetes, suggesting that islet cell autoimmunity is environmentally rather than genetically determined. Furthermore, the prevalence of islet cell antibodies was higher in the non-diabetic twins than in other first degree relatives of patients with insulin dependent diabetes. This implies that the prenatal or early postnatal period during which twins are exposed to the same environment, in contrast with that experienced by first degree relatives, is of aetiological importance. PMID:9169400

  6. Increased Fetal Plasma Erythropoietin in Monochorionic Twin Pregnancies With Selective Intrauterine Growth Restriction and Abnormal Umbilical Artery Doppler.

    PubMed

    Chang, Yao-Lung; Chao, An-Shine; Peng, Hsiu-Huei; Chang, Shuenn-Dyh; Su, Sheng-Yuan; Chen, Kuan-Ju; Cheng, Po-Jen; Wang, Tzu-Hao

    2016-08-01

    Hypoxia is the primary stimulus for the production of erythropoietin (EPO) in both fetal and adult life. Here, we investigated fetal plasma EPO concentrations in monochorionic (MC) twin pregnancies with selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery (UA) Doppler. We diagnosed sIUGR in presence of (1) birth-weight discordance >20% and (2) either twin with a birth weight <10th percentile. An abnormal UA Doppler was defined as a persistent absent-reverse end diastolic flow (AREDF). The intertwin EPO ratio was calculated as the plasma EPO level of the smaller (or small-for-gestational-age) twin divided by the EPO concentration of the larger (or appropriate-for-gestational-age (AGA)) twin. Thirty-two MC twin pairs were included. Of these, 17 pairs were normal twins (Group 1), seven pairs were twins with sIUGR without UA Doppler abnormalities (Group 2), and eight pairs were twins with sIUGR and UA Doppler abnormalities (Group 3). The highest EPO ratio was identified in Group 3 (p < .001) but no significant differences were observed between Groups 1 and 2. Fetal hemoglobin levels did not differ significantly in the three groups, and fetal EPO concentration did not correlate with gestational age at birth. We conclude that fetal plasma EPO concentrations are selectively increased in MC twin pregnancies with sIUGR and abnormal UA Doppler, possibly as a result of uncompensated hypoxia. PMID:27161360

  7. Impact of Monochorionicity and Twin to Twin Transfusion Syndrome on Prenatal Attachment, Post Traumatic Stress Disorder, Anxiety and Depressive Symptoms.

    PubMed

    Beauquier-Maccotta, Berengere; Chalouhi, Gihad E; Picquet, Anne-Laure; Carrier, Aude; Bussières, Laurence; Golse, Bernard; Ville, Yves

    2016-01-01

    Monochronioric (MC) twin pregnancies are considered as high-risk pregnancies with potential complications requiring in-utero interventions. We aimed to assess prenatal attachment, anxiety, post-traumatic stress disorder (PTSD) and depressive symptoms in MC pregnancies complicated with Twin-To-Twin-transfusion syndrome (TTTS) in comparison to uncomplicated monochorionic (UMC) and dichorionic pregnancies (DC). Auto-questionnaires were filled out at diagnosis of TTTS and at successive milestones. Prenatal attachment, PTSD, anxiety and perinatal depression were evaluated respectively by the Prenatal Attachment Inventory (PAI) completed for each twin, the Post-traumatic Checklist Scale (PCLS), the State-Trait Anxiety Inventory (STAI) and the Edinburgh Perinatal Depression Scale (EPDS). There was no significant difference in the PAI scores between the two twins. In the DC and UMC groups, PAI scores increased throughout pregnancy, whilst it didn't for TTTS group. TTTS and DC had a similar prenatal attachment while MC mothers expressed a significantly higher attachment to their fetuses and expressed it earlier. At the announcement of TTTS, 72% of the patients present a score over the threshold at the EPDS Scale, with a higher score for TTTS than for DC (p = 0.005), and UMC (p = 0.007) at the same GA. 30% of mothers in TTTS group have PTSD during pregnancy. 50% of TTTS- patients present an anxiety score over the threshold (STAI-Scale), with a score significantly higher in TTTS than in UMC (p<0.001) or DC (p<0.001). The proportion of subject with a STAI-State over the threshold is also significantly higher in TTTS than in DC at 20 GW (p = 0.01) and at 26 GW (p<0.05). The STAI-state scores in UMC and DC increase progressively during pregnancy while they decrease significantly in TTTS. TTTS announcement constitutes a traumatic event during a pregnancy with an important risk of PTSD, high level of anxiety and an alteration of the prenatal attachment. These results should guide

  8. Impact of Monochorionicity and Twin to Twin Transfusion Syndrome on Prenatal Attachment, Post Traumatic Stress Disorder, Anxiety and Depressive Symptoms

    PubMed Central

    Carrier, Aude; Bussières, Laurence; Golse, Bernard; Ville, Yves

    2016-01-01

    Monochronioric (MC) twin pregnancies are considered as high-risk pregnancies with potential complications requiring in-utero interventions. We aimed to assess prenatal attachment, anxiety, post-traumatic stress disorder (PTSD) and depressive symptoms in MC pregnancies complicated with Twin-To-Twin-transfusion syndrome (TTTS) in comparison to uncomplicated monochorionic (UMC) and dichorionic pregnancies (DC). Auto-questionnaires were filled out at diagnosis of TTTS and at successive milestones. Prenatal attachment, PTSD, anxiety and perinatal depression were evaluated respectively by the Prenatal Attachment Inventory (PAI) completed for each twin, the Post-traumatic Checklist Scale (PCLS), the State-Trait Anxiety Inventory (STAI) and the Edinburgh Perinatal Depression Scale (EPDS). There was no significant difference in the PAI scores between the two twins. In the DC and UMC groups, PAI scores increased throughout pregnancy, whilst it didn’t for TTTS group. TTTS and DC had a similar prenatal attachment while MC mothers expressed a significantly higher attachment to their fetuses and expressed it earlier. At the announcement of TTTS, 72% of the patients present a score over the threshold at the EPDS Scale, with a higher score for TTTS than for DC (p = 0.005), and UMC (p = 0.007) at the same GA. 30% of mothers in TTTS group have PTSD during pregnancy. 50% of TTTS- patients present an anxiety score over the threshold (STAI-Scale), with a score significantly higher in TTTS than in UMC (p<0.001) or DC (p<0.001). The proportion of subject with a STAI–State over the threshold is also significantly higher in TTTS than in DC at 20 GW (p = 0.01) and at 26 GW (p<0.05). The STAI-state scores in UMC and DC increase progressively during pregnancy while they decrease significantly in TTTS. TTTS announcement constitutes a traumatic event during a pregnancy with an important risk of PTSD, high level of anxiety and an alteration of the prenatal attachment. These results should

  9. Does amniotic fluid volume affect fetofetal transfusion in monochorionic twin pregnancies? Modelling two possible mechanisms

    NASA Astrophysics Data System (ADS)

    Umur, Asli; van Gemert, Martin J. C.; Ross, Michael G.

    2002-06-01

    Clinical evidence suggests that increased amniotic fluid volume due to polyhydramnios increases placental vascular resistance. We have sought to model the possible effects of an increased amniotic fluid volume on the net fetofetal transfusion in monochorionic twin pregnancies. We wanted to compare these effects with the results of previous simulations, which aimed to explain why the twin-twin transfusion syndrome (TTTS) placentas more often include bidirectional arteriovenous (AV) rather than AV plus arterioarterial (AA) anastomoses. We extended our mathematical model of TTTS by simulating two different mechanisms that increase the placental vascular resistance as a consequence of polyhydramnios. First, there is an increase in the placental capillary resistance and hence in deep AV and opposite AV (denoted as VA) resistances due to polyhydramnios. Second, there is an increase in the resistance of chorionic veins due to polyhydramnios, assuming that these veins act as Starling resistors. We then simulated the effects of polyhydramnios on different placental anastomotic patterns. The results were as follows. In the first mechanism (polyhydramnios affects AV-VA resistances), an increased amniotic fluid volume hardly affected bidirectional AV, but slightly decreased fetofetal transfusion in AV plus AA anastomoses. However, for these effects to change the natural development of the pregnancy, polyhydramnios needed to persist for approximately 4 weeks, and by comparing the effects of polyhydramnios with the effects of amnioreduction, amnioreduction was more beneficial for normalizing the donor amniotic fluid volume. Therefore, these beneficial effects due to polyhydramnios have no practical clinical significance. In the second mechanism (Starling resistor for chorionic veins), polyhydramnios slightly increased fetofetal transfusion and hence slightly increased TTTS severity in bidirectional AV and AV plus VV, but did not affect AV plus AA anastomoses. In conclusion, we

  10. Toward automatic phenotyping of retinal images from genetically determined mono- and dizygotic twins using amplitude modulation-frequency modulation methods

    NASA Astrophysics Data System (ADS)

    Soliz, P.; Davis, B.; Murray, V.; Pattichis, M.; Barriga, S.; Russell, S.

    2010-03-01

    This paper presents an image processing technique for automatically categorize age-related macular degeneration (AMD) phenotypes from retinal images. Ultimately, an automated approach will be much more precise and consistent in phenotyping of retinal diseases, such as AMD. We have applied the automated phenotyping to retina images from a cohort of mono- and dizygotic twins. The application of this technology will allow one to perform more quantitative studies that will lead to a better understanding of the genetic and environmental factors associated with diseases such as AMD. A method for classifying retinal images based on features derived from the application of amplitude-modulation frequency-modulation (AM-FM) methods is presented. Retinal images from identical and fraternal twins who presented with AMD were processed to determine whether AM-FM could be used to differentiate between the two types of twins. Results of the automatic classifier agreed with the findings of other researchers in explaining the variation of the disease between the related twins. AM-FM features classified 72% of the twins correctly. Visual grading found that genetics could explain between 46% and 71% of the variance.

  11. The promoter methylomes of monochorionic twin placentas reveal intrauterine growth restriction-specific variations in the methylation patterns

    PubMed Central

    He, Zhiming; Lu, Hanlin; Luo, Huijuan; Gao, Fei; Wang, Tong; Gao, Yu; Fang, Qun; Wang, Junwen

    2016-01-01

    Intrauterine growth restriction (IUGR) affects the foetus and has a number of pathological consequences throughout life. Recent work has indicated that variations in DNA methylation might cause placental dysfunction, which may be associated with adverse pregnancy complications. Here, we investigated the promoter methylomes of placental shares from seven monochorionic (MC) twins with selective intrauterine growth restriction (sIUGR) using the healthy twin as an ideal control. Our work demonstrated that the IUGR placental shares harboured a distinct DNA hypomethylation pattern and that the methylation variations preferentially occurred in CpG island shores or non-CpG island promoters. The differentially methylated promoters could significantly separate the IUGR placental shares from the healthy ones. Ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC‐MS/MS) further confirmed the genome‐wide DNA hypomethylation and the lower level of hydroxymethylation statuses in the IUGR placental shares. The methylation variations of the LRAT and SLC19A1 promoters, which are involved in vitamin A metabolism and folate transportation, respectively, and the EFS promoter were further validated in an additional 12 pairs of MC twins with sIUGR. Although the expressions of LRAT, SLC19A1 and EFS were not affected, we still speculated that DNA methylation and hydroxymethylation might serve a functional role during in utero foetal development. PMID:26830322

  12. The promoter methylomes of monochorionic twin placentas reveal intrauterine growth restriction-specific variations in the methylation patterns.

    PubMed

    He, Zhiming; Lu, Hanlin; Luo, Huijuan; Gao, Fei; Wang, Tong; Gao, Yu; Fang, Qun; Wang, Junwen

    2016-01-01

    Intrauterine growth restriction (IUGR) affects the foetus and has a number of pathological consequences throughout life. Recent work has indicated that variations in DNA methylation might cause placental dysfunction, which may be associated with adverse pregnancy complications. Here, we investigated the promoter methylomes of placental shares from seven monochorionic (MC) twins with selective intrauterine growth restriction (sIUGR) using the healthy twin as an ideal control. Our work demonstrated that the IUGR placental shares harboured a distinct DNA hypomethylation pattern and that the methylation variations preferentially occurred in CpG island shores or non-CpG island promoters. The differentially methylated promoters could significantly separate the IUGR placental shares from the healthy ones. Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) further confirmed the genome-wide DNA hypomethylation and the lower level of hydroxymethylation statuses in the IUGR placental shares. The methylation variations of the LRAT and SLC19A1 promoters, which are involved in vitamin A metabolism and folate transportation, respectively, and the EFS promoter were further validated in an additional 12 pairs of MC twins with sIUGR. Although the expressions of LRAT, SLC19A1 and EFS were not affected, we still speculated that DNA methylation and hydroxymethylation might serve a functional role during in utero foetal development. PMID:26830322

  13. Blood chimerism in a dizygotic dichorionic pregnancy.

    PubMed

    Jang, Ja-Hyun; Jung, Haiyoung; Kim, Jong-Hwa; Park, Won-Soon; Kim, Sun-Hee

    2010-10-01

    Blood chimerism in twins is known to occur through the transfer of hematopoietic stem cells between the fetuses via a common placenta. We present a case of blood chimerism in a dizygotic dichorionic twin pregnancy. The female twin was delivered at 34 weeks of gestation, and the male twin was stillborn. Pathologic examination confirmed dichorionic diamniotic placentas. The karyotype of the female child was obtained using peripheral blood sample, and it revealed a mixture of 46,XX and 46,XY cells (chi 46,XY[13]/46,XX[7]). FISH analysis performed on the buccal cells by using CEP X/Y probe (Abbott Molecular Inc., USA) revealed 100% XX signals (nuc ish Xcen(DXZ1x2)[500]). Gross examination of the external genitalia and abdominal ultrasonography revealed no definitive abnormal findings in relation to sex differentiation. When XX/XY chimerism is present in blood lymphocytes, careful examination of external genitalia and reproductive organs and further studies are required to detect chimerism in non-hematopoetic tissues. This is a rare case of blood chimerism in dichorionic placentas, in contrast to those in monochorionic placentas. PMID:20890086

  14. Ulcerative colitis and Crohn's disease in an unselected population of monozygotic and dizygotic twins. A study of heritability and the influence of smoking.

    PubMed Central

    Tysk, C; Lindberg, E; Järnerot, G; Flodérus-Myrhed, B

    1988-01-01

    By running the Swedish twin registry containing about 25,000 pairs of twins of the same sex together with the central national diagnosis register of hospital inpatients, 80 twin pairs suffering from inflammatory bowel disease were found. In the ulcerative colitis group one of 16 monozygotic pairs was concordant for the disease, but all the other 20 pairs (dizygotic or unknown zygosity) were discordant. In the Crohn's disease group eight of 18 monozygotic pairs and one of 26 dizygotic pairs were concordant. The proband concordance rate among monozygotic twins was 6.3% for ulcerative colitis and 58.3% for Crohn's disease. The calculated heritability of liability based on monozygotic pairs was 0.53 and 1.0 respectively. Thus heredity as an aetiological factor is stronger in Crohn's disease than in ulcerative colitis. Monozygotic twins with Crohn's disease were more likely to be smokers than monozygotic twins with ulcerative colitis. Smoking did not explain the discordance of twin pairs with either ulcerative colitis, or Crohn's disease. The combination of identical heredity and similar smoking habit is not sufficient to cause disease. PMID:3396969

  15. The Contribution of Prenatal Stress to the Pathogenesis of Autism as a Neurobiological Developmental Disorder: A Dizygotic Twin Study

    ERIC Educational Resources Information Center

    Claassen, M.; Naude, H.; Pretorius, E.; Bosman, M. C.

    2008-01-01

    This paper reports on the contribution of prenatal stress to the pathogenesis of autism as a neurobiological developmental disorder in a dizygotic study. The aim was to explore whether the neurobiological impact of stress prior to week 28 of gestation might be related to the pathogenesis of autism. The following data-generating strategies were…

  16. X-chromosome inactivation is mostly random in placental tissues of female monozygotic twins and triplets

    SciTech Connect

    Bamforth, F.; Machin, G.; Innes, M.

    1996-01-22

    Patterns of X-chromosome inactivation in chorion, amnion, and cord from 79 pairs of twins were examined. Seven sets of triplets were included in the analysis, both as twin pairs and triplets. Twins were stratified as dizygotic (DZ), monozygotic (MZ), monochorionic, and dichorionic and were selected for birth weight discordance, discordance for congenital anomalies, twin-twin transfusion syndrome, and various patterns of vascular anastomosis. X-inactivation was predominantly symmetric. Chorion was the most likely tissue to show asymmetric X-inactivation and was found most frequently in MZ dichorionic twins. There was no correlation of X-inactivation pattern with the selected clinical criteria. This study does not confirm that asymmetric X-inactivation in embryonic tissues is a common phenomenon in female twins, including monozygotic twins. 27 refs., 2 figs., 9 tabs.

  17. Monochorionic twin delivery after conservative surgical treatment of a patient with severe diffuse uterine adenomyosis without uterine rupture

    PubMed Central

    Kwack, Jae Young; Jeon, Su-Bun; Kim, Keuna; Lee, Soo-Jeong

    2016-01-01

    A 31-year-old nulliparous woman with severe diffuse uterine adenomyosis, which replaced nearly the whole uterine myometrium, visited our hospital due to severe dysmenorrhea, menorrhagia, and a desire to have a baby. The patient had a history of two spontaneous abortions. Laparotomic adenomyomectomy with transient occlusion of uterine arteries (TOUA) was performed safely and the patient tried in vitro fertilization and achieved a intrauterine twin pregnancy after recovery time of the operation. At 31+6 weeks of gestation, a male neonate baby weighing 1,620 g and a male neonate baby weighing 1,480 g were born by transverse lower segment cesarean delivery. There was no complication after the operation. The babies were discharged after receiving routine neonatal intensive care for neonatal respiratory distress syndrome. Adenomyomectomy with TOUA technique would be an option for conservative surgical treatment in patients with severe diffuse whole uterine adenomyosis. This is the first report of twin pregnancy after diffuse whole uterine adenomyomectomy with TOUA. PMID:27462599

  18. Monochorionic twin delivery after conservative surgical treatment of a patient with severe diffuse uterine adenomyosis without uterine rupture.

    PubMed

    Kwack, Jae Young; Jeon, Su-Bun; Kim, Keuna; Lee, Soo-Jeong; Kwon, Yong Soon

    2016-07-01

    A 31-year-old nulliparous woman with severe diffuse uterine adenomyosis, which replaced nearly the whole uterine myometrium, visited our hospital due to severe dysmenorrhea, menorrhagia, and a desire to have a baby. The patient had a history of two spontaneous abortions. Laparotomic adenomyomectomy with transient occlusion of uterine arteries (TOUA) was performed safely and the patient tried in vitro fertilization and achieved a intrauterine twin pregnancy after recovery time of the operation. At 31+6 weeks of gestation, a male neonate baby weighing 1,620 g and a male neonate baby weighing 1,480 g were born by transverse lower segment cesarean delivery. There was no complication after the operation. The babies were discharged after receiving routine neonatal intensive care for neonatal respiratory distress syndrome. Adenomyomectomy with TOUA technique would be an option for conservative surgical treatment in patients with severe diffuse whole uterine adenomyosis. This is the first report of twin pregnancy after diffuse whole uterine adenomyomectomy with TOUA. PMID:27462599

  19. Within-pair differences in a-b ridge count asymmetry in monozygotic twins: evidence for a placental proximity effect.

    PubMed

    Bogle, A C; Reed, T; Norton, J A

    1994-01-01

    Asymmetry of a-b ridge count, a dermatoglyphic trait in the second interdigital (ID II) palmar area was studied in 314 identical (MZ) twin-pairs of known placental type. Statistically significant differences were observed for the variability of a-b ridge count with respect to placentation. Monochorionic MZ pairs displayed more within-pair variability than dichorionic MZ twins. Within dichorionic pairs, greater variability was observed in MZ twins when pairs with fused placentas were compared with those with separate placentas. A similar pattern of greater variability in dichorionic fused versus dichorionic separate placentas was also found in 121 same sex dizygotic twin-pairs. The pattern of within-pair differences was consistent with a placental proximity effect like that known for the variability in birth weight in twins. PMID:8039800

  20. A Study of Developmental Speech and Language Disorders in Twins.

    ERIC Educational Resources Information Center

    Lewis, Barbara A.; Thompson, Lee A.

    1992-01-01

    Fifty-seven same-sex twin sets (32 monozygotic and 25 dizygotic) were examined for concordance of speech and language disorders. Monozygotic twins had a higher concordance than dizygotic twins and also were more similar in the types of disorders they presented than dizygotic twins. Positive family histories were reported for both groups.…

  1. The North American Fetal Therapy Network Consensus Statement: prenatal management of uncomplicated monochorionic gestations.

    PubMed

    Emery, Stephen P; Bahtiyar, Mert Ozan; Dashe, Jodi S; Wilkins-Haug, Louise E; Johnson, Anthony; Paek, Bettina W; Moon-Grady, Anita J; Skupski, Daniel W; OʼBrien, Barbara M; Harman, Christopher R; Simpson, Lynn L

    2015-05-01

    Owing to vascular connections within a single placenta, monochorionic gestations present distinctive prenatal management challenges. Complications that can arise as a result of unbalanced hemodynamic exchange (twin-twin transfusion syndrome and twin anemia polycythemia sequence) and unequal placental sharing (selective fetal growth restriction) should be kept in mind while prenatal management is being planned. Because of unique monochorionic angioarchitecture, what happens to one twin can directly affect the other. Death of one twin can result in death or permanent disability of the co-twin. Early detection of these unique disease processes through frequent ultrasonographic surveillance may allow the opportunity for earlier referral, intervention, or both and potentially better outcomes. Therefore, monochorionic gestations should be managed differently than dichorionic gestations or singletons. The purpose of this document is to present in detail methods for monitoring and management of uncomplicated monochorionic gestations and to review the evidence for the roles of these methods for detection of complications in clinical practice. Finally, we present evidence-based and expert opinion-supported recommendations developed by the North American Fetal Therapy Network for the diagnosis, surveillance, and delivery of uncomplicated monochorionic gestations. PMID:25932853

  2. Chorionicity and Heritability Estimates from Twin Studies: The Prenatal Environment of Twins and Their Resemblance Across a Large Number of Traits.

    PubMed

    van Beijsterveldt, C E M; Overbeek, L I H; Rozendaal, L; McMaster, M T B; Glasner, T J; Bartels, M; Vink, J M; Martin, N G; Dolan, C V; Boomsma, D I

    2016-05-01

    There are three types of monozygotic (MZ) twins. MZ twins can either share one chorion and one amnion, each twin can have its own amnion, or MZ twins can-like dizygotic twins-each have their own chorion and amnion. Sharing the same chorion may create a more similar/dissimilar prenatal environment and bias heritability estimates, but most twin studies do not distinguish between these three types of MZ twin pairs. The aim of this paper is to investigate the effect of chorion sharing on the similarity within MZ twin pairs for a large number of traits. Information on chorion status was obtained for the Netherlands twin register (NTR) by linkage to the records from the database of the dutch pathological anatomy national automated archive (PALGA). Record linkage was successful for over 9000 pairs. Effect of chorion type was tested by comparing the within-pair similarity between monochorionic (MC) and dichorionic (DC) MZ twins on 66 traits including weight, height, motor milestones, child problem behaviors, cognitive function, wellbeing and personality. For only 10 traits, within-pair similarity differed between MCMZ and DCMZ pairs. For traits influenced by birth weight (e.g. weight and height in young children) we expected that MC twins would be more discordant. This was found for 5 out of 13 measures. When looking at traits where blood supply is important, we saw MCMZ twins to be more concordant than DCMZ's for 3 traits. We conclude that the influence on the MZ twin correlation of the intra-uterine prenatal environment, as measured by sharing a chorion type, is small and limited to a few phenotypes. This implies that the assumption of equal prenatal environment of mono- and DC MZ twins, which characterizes the classical twin design, is largely tenable. PMID:26410687

  3. The Syntactic Abilities of Identical Twins, Fraternal Twins, and Their Siblings

    ERIC Educational Resources Information Center

    Munsinger, Harry; Douglass, Arthur, II

    1976-01-01

    The language development of monozygotic twins, same-sex dizygotic twins, siblings of monozygotic twins, and siblings of dizygotic twins, ages 3-17, was studied to estimate how much of the individual variation in children's language skills results from genetic factors and how much from environmental experience. (BRT)

  4. The Placenta in Twin-to-Twin Transfusion Syndrome and Twin Anemia Polycythemia Sequence.

    PubMed

    Couck, Isabel; Lewi, Liesbeth

    2016-06-01

    Twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS) are complications unique to monochorionic twin pregnancies and their shared circulation. Both are the result of the transfusion imbalance in the intertwin circulation. TTTS is characterized by an amniotic fluid discordance, whereas in TAPS, there is a severe discordance in hemoglobin levels. The article gives an overview of the typical features of TTTS and TAPS placentas. PMID:27098457

  5. Single Base-Resolution Methylome of the Dizygotic Sheep

    PubMed Central

    Liu, Bin; Su, Rui; Jiang, Yu; Wang, Wen; Dong, Yang

    2015-01-01

    Sheep is an important livestock in the world for meat, dairy and wool production. The third version of sheep reference genome has been recently assembled, but sheep DNA methylome has not been profiled yet. In this study, we report the comprehensive sheep methylome with 94.38% cytosine coverage at single base resolution by sequencing DNA samples from Longissimus dorsi of dizygotic Sunit sheep, which were bred in different habitats. We also compared methylomes between the twin sheep. DNA methylation status at genome-scale differentially methylated regions (DMRs), functional genomic regions and 248 DMR-containing genes were identified between the twin sheep. Gene ontology (GO) and KEGG annotations of these genes were performed to discover computationally predicted function. Lipid metabolism, sexual maturity and tumor-associated categories were observed to significantly enrich DMR-containing genes. These findings could be used to illustrate the relationship between phenotypic variations and gene methylation patterns. PMID:26536671

  6. Do Parents Create, or Respond to, Differences in Twins?

    ERIC Educational Resources Information Center

    Lytton, Hugh

    1977-01-01

    In a twin study using direct behavioral observation of parent-child interaction, as well as ratings and experimental measures, the question of parents' differential treatment of monozygotic and dizygotic twins was investigated. (Author/SB)

  7. Twins and Siblings: Concordance for School-Age Mental Development

    ERIC Educational Resources Information Center

    Wilson, Ronald S.

    1977-01-01

    The analysis of WISC scores for 314 school-age twins and 221 of their siblings revealed high concordance of full-scale and verbal IQ for monozygotic twins. The IQ concordance for dizygotic twins, twin-sibling pairs, and sibling pairs were comparable to each other but significantly lower than that for monozygotic twins. (Author/JMB)

  8. [Ultrasonography of twin pregnancies].

    PubMed

    Grignon, A; Dubois, J

    2002-12-01

    Sonographers must be familiar with the diagnostic tools available to them for determining twin pregnancy type. During the first trimester, these tools include the number of chorionic sacs, the number of yolk sacs, and the presence of an inter-twin membrane. During the second trimester, sonographers must look for a difference in sex, the presence of two separate placentas, and a thick vs. thin membrane, or the absence of a membrane. Complications are frequent in twin pregnancies and may be maternal or fetal. Measuring cervical length is the only way for sonographers to predict pre-term labour. A cervical length of< or =2.5 cm before 23 weeks is significant. Some fetal anomalies are more frequent in twin pregnancy than in single pregnancy. The more frequent are: esophageal atresia, omphalocele and cardiac anomalies. Some fetal anomalies are peculiar to twin pregnancy: Siamese twins, digestive atresia, craniofacial deformation and club-foot. A significant growth asymmetry is defined as a CRL of 3 or more millimetres and a difference of 20% in weight. The poly-oligo sequence represents a severe level asymmetry of amniotic fluid in monodiamniotic twins where survival rate without sequelae is 13.6%. The twin-twin transfusion syndrome is an event occurring after the apparition of the poly-oligo sequence, which manifests by discordances in weight and hemodynamic changes leading to myocardial repercussion. Twin embolization syndrome follows the in utero death of a co-twin in a monochorionic twin pregnancy; ischemic events must be monitored in such cases. Cord entanglement is unpredictable and is specific to monochorionic monoamniotic twin pregnancies. Finally, an acardius is a parasitic twin that feeds on its co-twin, resulting in the viable twin's death in 50% of cases. PMID:12592152

  9. Twins and endocrinology

    PubMed Central

    Hari Kumar, K. V. S.; Modi, K. D.

    2014-01-01

    Twins are two independent babies delivered during the same pregnancy and are divided as monozygotic or dizygotic based on their origin. Dizygotic twins are similar to two siblings and have different genetic information. In contrary, monozygotic twins have a similar genetic identity and provide a unique opportunity to evaluate the contribution of genetic and environmental factors of the disease. The endocrine and metabolic disorders affect a large number of the population including the twins. Diabetes, obesity, and autoimmune thyroid disease are the most common endocrine disorders in general practice. It is essential to understand the genetic basis of endocrine disorders for therapy, prognostication and risk assessment for future generations. In this article, we review the endocrine disorders in relation to their occurrence in monozygotic twins to highlight the genetic and environmental contribution. PMID:25538877

  10. Comparison Between Monochorionic and Dichorionic Placentas With Special Attention to Vascular Anastomoses and Placental Share.

    PubMed

    Zhao, Depeng; Lipa, Michal; Wielgos, Miroslaw; Cohen, Danielle; Middeldorp, Johanna M; Oepkes, Dick; Lopriore, Enrico

    2016-06-01

    Placental vascular anastomoses in twins lead to a shared circulation and may subsequently enable the development of severe complications such as twin-twin transfusion syndrome (TTTS) and twin anemia-polycythemia sequence (TAPS). The presence of vascular anastomoses has frequently and systematically been studied in monochorionic (MC) placentas, but only rarely in dichorionic (DC) placentas. The aim of this study was to compare the prevalence of vascular anastomoses and evaluate the sharing discordance in MC and DC placentas. All consecutive placentas of MC and DC twins delivered at the Leiden University Medical Center (the Netherlands) and Medical University of Warsaw (Poland) from 2012 to 2015 were routinely injected with colored dye and included in the study. We excluded twin pregnancies treated with fetoscopic laser surgery. A total of 258 placentas were analyzed in this study, including 134 MC placentas and 124 DC placentas. Vascular anastomoses were present in 99% (133/134) of MC placentas and 0% of DC placentas (p < .01). Placental share discordance between MC twins was significantly larger compared to DC twins, 19.8 (interquartile range [IQR] 8.1-33.3) and 10.8 (IQR 6.2-19.0), respectively (p < .01). Vascular anastomoses associated complications occurred in 16% (22/134) MC twins. Our findings show that vascular anastomoses are almost ubiquitous in MC placentas, but non-existent in DC placentas. In addition, unequal placental sharing appears to be more common in MC than in DC placentas. PMID:27068823

  11. Diagnosis and Management of Twin-Twin Transfusion Syndrome.

    PubMed

    Johnson, Anthony

    2015-09-01

    Twin-twin transfusion syndrome (TTTS) affects 10% to 15% of monochorionic pregnancies. In the absences of timely diagnosis and intervention perinatal loss or long term developmental delay can be expected in over 90% of cases. Establishing chorionicity in the first trimester followed by serial ultrasounds beginning at 16 weeks of gestation and intervention with placental laser ablation before the development of advance disease overall survival rates can be expected in 70% to 80% of cases. PMID:26165181

  12. Infant Temperament and Genetics: An Objective Twin Study of Motor Activity Level.

    ERIC Educational Resources Information Center

    Saudino, Kimberly J.; Eaton, Warren O.

    1991-01-01

    The activity level of 60 pairs of infant twins was measured for 2 days. Differences in activity level for monozygotic and dizygotic twins, as indicated by motion recorders and parent ratings, showed evidence of genetic influences. (BC)

  13. Cardiac Manifestations of Twin-to-Twin Transfusion Syndrome.

    PubMed

    Manning, Nicky; Archer, Nick

    2016-06-01

    This review addresses the physiology of monochorionic diamniotic (MC/DA) twins and the potential for twin-twin transfusion syndrome (TTTS). It focuses on the underlying cardiovascular pathophysiology of TTTS and the cardiovascular impact of TTTS for both the recipient and the donor twin. It explains the principles for assessment and monitoring of these cardiovascular changes and how these may be used to guide pregnancy management. Finally, it describes the effect of treatment on the altered hemodynamics and how this can influence pregnancy and perinatal management, as well as longer-term follow-up. PMID:27087122

  14. Neonatal Temperament in Monozygotic and Dizygotic Twin Pairs.

    ERIC Educational Resources Information Center

    Reise, Marilyn L.

    1990-01-01

    Findings indicated that zygosity was not related to behavioral scores during the neonatal period, and that environment substantially influenced neonatal temperament. Specific perinatal indicators of risk were found to account for some of the intrapair differences in behavioral variables. (RH)

  15. Emergent Novelties in the Mentality of Dizygotic Twins.

    ERIC Educational Resources Information Center

    Bierschenk, Bernhard

    Scanator is an extremely valuable tool in the functional analysis of qualitative stability in text building behavior during writing. Scanator also allows for a detailed investigation of subtle changes emerging in the structural relations of emergent novelties. This study focused on the extension of the application of Scanator to one pair of…

  16. Gestational age at delivery and neonatal outcome in uncomplicated twin pregnancies: what is the optimal gestational age for delivery according to chorionicity?

    PubMed Central

    Lee, Hye-Jung; Kim, Soo Hyun; Chang, Kylie Hae-Jin; Sung, Ji-Hee; Oh, Soo-young; Roh, Cheong-Rae; Kim, Jong-Hwa

    2016-01-01

    Objective To investigate the neonatal outcome according to the gestational age at delivery and to determine the optimal timing for delivery in uncomplicated monochorionic and dichorionic twin pregnancies. Methods This is a retrospective cohort study of women with uncomplicated twin pregnancies delivered at or beyond 35 weeks of gestation from 1995 to 2013. The primary outcome was neonatal composite morbidity, which was defined as when either one or both twins have one or more of the followings: fetal death after 35 weeks gestation, admission to neonatal intensive care unit, mechanical ventilator requirement, respiratory distress syndrome and neonatal death. To determine the optimal gestational age for delivery according to chorionicity, we compared the neonatal composite morbidity rate between women who delivered and women who remained undelivered at each gestational week in both monochorionic and dichorionic twin pregnancies. Results A total of 697 twin pregnancies were included (171 monochorionic and 526 dichorionic twins). The neonatal composite morbidity rate significantly decreased with advancing gestational age at delivery and its nadir was observed at 38 and ≥39 weeks of gestation in monochorionic and dichorionic twins, respectively. However, the composite morbidity rate did not differ between women who delivered and women who remained undelivered ≥36 and ≥37 weeks in monochorionic and dichorionic twins, respectively. Conclusion Our data suggest that the optimal gestational age for delivery was at ≥36 and ≥37 weeks in uncomplicated monochorionic and dichorionic twin pregnancies, respectively. PMID:26866030

  17. The Development of Empathy in Twins.

    ERIC Educational Resources Information Center

    Zahn-Waxler, Carolyn; And Others

    1992-01-01

    Observational measures of monozygotic and dizygotic twins' reactions to simulations of distress in others were obtained when the twins were 14 and 20 months old. Components of concern for others increased with age. Girls scored higher than boys on most measures. There was modest evidence for heritability of empathy. (BC)

  18. Special forms in twin pregnancy - ACARDIAC TWIN/ Twin reversed arterial perfusion (TRAP) sequence

    PubMed Central

    Anca, FA; Negru, A; Mihart, AE; Grigoriu, C; Bohîlțea, RE; Șerban, A

    2015-01-01

    Twin pregnancy generally represents a high-risk pregnancy, but monozygous twin pregnancy is a real challenge for the obstetrician due to the serious complications that may occur during its evolution. A very rare, severe complication of monozygous twin pregnancy, which we recently dealt with in the Obstetrics and Gynecology Department of the University Emergency Hospital Bucharest, was a monochorionic monoamniotic twin pregnancy with acardiac twin (TRAP). One of the fetuses (acardiac twin) presented a rudimentary unfunctional heart or even no heart at all, underdeveloped inferior part of the body and head, being transfused by the other fetus with a normal heart (pumping twin) by one superficial arterio-arterial anastomosis through which blood pumped backwards. The understanding of these cases is mandatory in order to offer maximum survival and heath chances to the viable fetus. Abbreviations: RFA = radiofrequency ablation, TRAP = reversed arterial perfusion PMID:26664482

  19. Twin Reversed Arterial Perfusion Syndrome (TRAP or Acardiac Twin)-A Case Report

    PubMed Central

    R., Kalyani; Bindra, Mandeep S.

    2014-01-01

    Twin reversed arterial perfusion (TRAP) syndrome is a rare condition (0.3:10,000 births) that occurs in monochorionic twin pregnancies, resulting in coexistence of a normal “pump” twin and an acardiac twin. The acardiac twin is dependent upon the normal twin to provide circulation by means of vascular anastomosis. Many of the bizarre defects are felt to be caused by low oxygen tension and this causes dramatic alteration in the twin fetal physiology and high prenatal mortality. The acardiac twin is a parasite, putting the pump fetus at risk of high output cardiac failure. Overall only 50% of pump twins survive. We present a case in a twenty year female, gravida two, para one, living one, full term normal pregnancy, ultrasound showed twin pregnancy. Following delivery, the first fetus survived only for one day and the second fetus showed features of TRAP syndrome. PMID:24596758

  20. A twin study on age-related macular degeneration.

    PubMed Central

    Meyers, S M

    1994-01-01

    A prospective twin study on age-related macular degeneration (AMD) recruited 83 monozygotic pairs, 28 dizygotic pairs, and one triplet set from 1986 through 1993. Zygosity was determined by genetic testing of red cell markers, HLA antigens, or specific DNA loci. There were no twin pairs in which I collected data on only one twin. To decrease ascertainment bias, after 1991 the recruitment notice did not mention AMD, and I did not ask about a history of eye disease before the eye examination. Because of this, twin pairs recruited from 1986 through 1991 were statistically analyzed separately from those after January 1, 1992. From 1986 through 1991, 23 twin pairs were recruited; 11 monozygotic and 2 dizygotic pairs had nonAMD retinal changes or no retinal abnormalities, 9 monozygotic pairs with AMD were all concordant, and 1 dizygotic pair was discordant for basal laminar drusen. The concordance rate of AMD did not differ significantly between monozygotic and dizygotic twin pairs (P = .10) for 1986 through 1991. In 1992 and 1993, 88 twin pairs and one triplet set were recruited; 49 monozygotic and 19 dizygotic pairs had nonAMD retinal changes or no retinal abnormalities, 14 monozygotic pairs with AMD were all concordant, and 2 of 7 dizygotic pairs were concordant for AMD. The nonidentical triplets (1 with and 2 without AMD) were categorized as one of the discordant dizygotic pairs in the statistical evaluation. In nontwin age-matched (within 2 or 5 years of age) or age- and sex-matched sibling pairs the concordance rate of AMD ranged from 16% to 25%. The concordance rate of AMD was significantly higher in monozygotic than in dizygotic twins (P = .001) for 1992 and 1993. The concordance rate was higher for monozygotic twin pairs recruited in 1992 and 1993 than in any of the four subsets of nontwin age-method or age- and sex-matched sibling pairs (P < .0001). Overall, from 1986 through 1993, 23 of 23 monozygotic and 2 of 8 dizygotic twin pairs were concordant for AMD

  1. What you need to know when managing twins: 10 key facts.

    PubMed

    Simpson, Lynn L

    2015-06-01

    Twin pregnancies can be complicated. Early diagnosis with accurate dating, determination of chorionicity, screening for chromosomal and structural abnormalities, placental evaluation, and cervical length assessment should be completed in the first half of gestation. Routine fetal growth is recommended for all twins with serial surveillance for those complicated by anomalies, cervical shortening, growth disturbances, and amniotic fluid abnormalities. Twins with monochorionic placentation require heightened scrutiny for unequal placental sharing with discordant twin growth or selective intrauterine fetal growth restriction, twin-twin transfusion syndrome, twin anemia-polycythemia sequence, and single-fetal demise. Familiarity with essentials can assist practitioners involved in the management of twins. PMID:26002163

  2. Long-Term Neurodevelopmental Outcome in Survivors of Twin-to-Twin Transfusion Syndrome.

    PubMed

    van Klink, Jeanine M M; Koopman, Hendrik M; Rijken, Monique; Middeldorp, Johanna M; Oepkes, Dick; Lopriore, Enrico

    2016-06-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monochorionic (MC) twin pregnancies associated with high perinatal mortality and morbidity rates. Management in TTTS is a major challenge for obstetricians and neonatologists. Twins with TTTS are often born prematurely after an extremely distressing and highly hazardous fetal period. Follow-up studies report varying rates of cerebral palsy (CP) and long-term neurodevelopmental impairment (NDI). This review discusses the latest findings on the long-term outcome of TTTS survivors, possible risk factors for long-term impairment, and provides recommendations for future research. PMID:27137794

  3. PennTwins: A Population-Based Cohort for Twin Studies

    PubMed Central

    Coccaro, Emil F.; Jacobson, Kristen C.

    2014-01-01

    The current article describes the creation and composition of the PennTwins Cohort and provides details on the demographic characteristics of the sample. The PennTwins Cohort was developed using a population-based method of ascertainment and currently has 9401 28- to 47-year-old twins, including 2225 confirmed twin pairs and 4951 twins whose co-twins have not yet registered. Zygosity data have been used to identify 919 monozygotic, 634 same-sex dizygotic, and 445 opposite-sex dizygotic pairs. GeoCode data on gender, age, and certain demographic characteristics were obtained for the addresses of all twins who were mailed invitations to be part of the cohort. Analysis of the available data show only very small differences between twins who are currently part of the PennTwins Cohort and potential twins who either did not respond to recruitment or who could not be located. Similarly, only very small demographic differences exist between twins from complete pairs and twins whose co-twins are not yet registered, and there are no differences across zygosity. Thus, despite a relatively low overall response rate (12% of all twins born in Pennsylvania from 1959–1978), there is no evidence that the sample differs in any meaningful respect from the larger population. PMID:17254443

  4. The Heritability of Inhibited and Uninhibited Behavior: A Twin Study.

    ERIC Educational Resources Information Center

    Robinson, JoAnn L.; And Others

    1992-01-01

    Behaviors of monozygotic and dizygotic twins that were indicative of wariness were observed when the twins were 14, 20, and 24 months of age. An index of inhibition constructed from observations showed internal consistency at all ages and stability across ages. Heritability was a factor at all ages. (BC)

  5. Head Circumferences in Twins with and without Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Froehlich, Wendy; Cleveland, Sue; Torres, Andrea; Phillips, Jennifer; Cohen, Brianne; Torigoe, Tiffany; Miller, Janet; Fedele, Angie; Collins, Jack; Smith, Karen; Lotspeich, Linda; Croen, Lisa A.; Ozonoff, Sally; Lajonchere, Clara; Grether, Judith K.; Hallmayer, Joachim

    2013-01-01

    To determine the genetic relationship between head circumference (HC) and Autism Spectrum Disorders (ASDs). Twin pairs with at least one twin with an ASD were assessed. HCs in affected and unaffected individuals were compared, as were HC correlations in monozygotic and dizygotic pairs. 404 subjects, ages 4-18, were included. 20% of males and 27%…

  6. Variations in the Binary Conception Model in Twinning.

    ERIC Educational Resources Information Center

    Lord, Thomas R.

    1988-01-01

    Presents a brief summary of the transformation of a single fertilized ovum into a multi-celled human. Discusses the similarities and differences of identical and non-identical twins. Cites twin pairs that do not neatly fit the monozygotic or dizygotic schemes of human development. (RT)

  7. Gleanings from Identical Twins Studying Science.

    ERIC Educational Resources Information Center

    Mascazine, John R.

    This paper explains and summarizes the results of a study that investigated the ways in which monozygotic (identical) and dizygotic (fraternal) twins learn. Their individual learning style elements were specifically investigated according to the Dunn and Dunn model. This paper discusses the themes, unique needs, and characteristics monozygotic…

  8. Monthly trend and seasonal variation in twinning rate in Japan, 1975-1994

    NASA Astrophysics Data System (ADS)

    Nonaka, K.; Imaizumi, Yoko

    We examined birth records from Japanese statistics, 1975-1994, to investigate the seasonality of twin births. We could identify 198 924 pairs of twins (97.9% of all the registered twin records) and estimated the numbers of mono- and dizygotic twin pairs. The seasonal index of the twinning rate for each month was calculated by dividing the crude rate by the estimated trend value for the month. There were significant variations in the seasonal index for overall, dizygotic and monozygotic twinning rates. Peak months with values more than 3% higher than expected were July and October-December for dizygotic twins, and April and June for monozygotic twins; these seasonalities were statistically significant by analysis of variance and the patterns were similar in recent years, with a sharp increase in the total twinning rate. When observed year-by-year, however, there were years that did not show these typical seasonalities. It is suggested that the mechanisms for probable seasonal variations in twinning rates are different for dizygotic and monozygotic twin pregnancies, and that factors involved in these variations are not effective every year.

  9. The East Flanders Prospective Twin Survey (EFPTS).

    PubMed

    Derom, Catherine A; Vlietinck, Robert F; Thiery, Evert W; Leroy, Fernand O G; Fryns, Jean-Pierre; Derom, Robert M

    2006-12-01

    The East Flanders Prospective Twin Survey (EFPTS) is a prospective, population-based registry of multiple births in the province of East Flanders, Belgium. EFPTS has several unique features: it is population based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are ascertained at birth; basic perinatal data recorded; chorion type and zygosity established; and since 1969 placental biopsies have been taken and frozen at -20 degrees C for later determination of genetic markers. The EFPTS is the only large register that includes placental data and allows differentiation of 3 subtypes of monozygotic (MZ) twins based on the time of the initial zygotic division: the dichorionic-diamnionic pairs (early, before the 4th day after fertilization), the monochorionic-diamnionic pairs (intermediate, between the 4th and the 7th day post fertilization), and the monochorionic-monoamnionic pairs (late, after the 8-day post fertilization). This added a new dimension to didymology (the science of twins; didymos is the Greek word for twin): the timing of MZ twinning. Studies can be initiated taking into account primary biases, those originating in utero. Such studies could throw new light on the controversy over the validity of the classic twin method, the consequences of early embryological events (before and just after implantation of the embryo), the origin of congenital malformations, the sex proportion of multiples, the gene-environment interactions as far as intrauterine environment is concerned, to name but a few. PMID:17254399

  10. Twin Reversed Arterial Perfusion Sequence (TRAPS): An Illustrative Series of 13 Cases.

    PubMed

    Ruiz-Cordero, Roberto; Birusingh, Rhea J; Pelaez, Liset; Azouz, Michel; Rodriguez, Maria Matilde

    2016-01-01

    Twin reversed-arterial-perfusion sequence (TRAPS) is a rare and severe complication of monochorionic twin pregnancies. It usually occurs in the setting of monochorionic placentation, when the heart of a normal appearing twin serves as the pump for one or more dysmorphic twins whose head, thoracic organs, and upper extremities do not fully develop or do not develop at all and thus lack cardiac activity. Anomalous vascular placental architecture causes a shift in arterial flow towards the acardiac twin(s). The exact physiopathologic mechanisms that lead to this devastating phenomenon are not well known. We reviewed the maternal history and the surgical pathology reports of the fetuses and placentas of 13 different cases of TRAPS that were collected in a 23-year study period at a single institution. Herein we summarize the characteristic findings and illustrate specific mechanical feto-placental circulation issues that appear to be instrumental in the development of TRAPS. PMID:26847661

  11. [Role of twin reversed arterial perfusion syndrome in the development of fetus acardius].

    PubMed

    Nizyaeva, N V; Kostyukov, K V; Gladkova, K A; Kulikova, G V; Shchegolev, A I

    2016-01-01

    Monochorionic multiple pregnancy has a higher risk for obstetric complications, including those due to the development of twin-to-twin transfusion syndrome and reversed arterial perfusion syndrome (TRAP sequence). The latter occurs in 0.1% of all monochorionic pregnancies. The basis for TRAP sequence is a relationship between arterial and venous anastomoses from the appropriate placental areas, causing a recipient fetus to develop at the expense of a donor fetus. The presence of abnormal anastomoses is considered to be a main cause of acardia. The prognosis for a donor fetus is also unfavorable: the mortality rates in the absence of intrauterine correction are as high as 55%. PMID:27600783

  12. The History of Treatment of Twin-to-Twin Transfusion Syndrome.

    PubMed

    Glennon, Chelsea L; Shemer, Scott A; Palma-Dias, Ricardo; Umstad, Mark P

    2016-06-01

    Historical suggestions of twin-to-twin transfusion syndrome (TTTS) date back to the early 17th century. Placental anastomoses were first reported in 1687; however, it was Schatz who first identified their importance in 1875. He recognized 'the area of transfusion' within the 'villous district' of the placenta, which he named the 'third circulation'. This article describes how the management of TTTS has evolved as we have gained a more sophisticated understanding and appreciation of the complex vascular anastomoses that exist in monochorionic twin placentae. Currently, fetosopic laser occlusion is the preferred treatment option for TTTS. PMID:27203604

  13. Alloparenting for chimpanzee twins

    PubMed Central

    Kishimoto, Takeshi; Ando, Juko; Tatara, Seiki; Yamada, Nobuhiro; Konishi, Katsuya; Kimura, Natsuko; Fukumori, Akira; Tomonaga, Masaki

    2014-01-01

    In April 2009, a female chimpanzee named Sango, living in a captive group at the Noichi Zoo, Japan, gave birth to dizygotic male-female twin chimpanzees (male: Daiya, female: Sakura). The extent to which adult group members cared for the twins was investigated using a focal animal sampling method targeting six adults (one male) when the twin chimpanzees were two years old. Data were collected for an average of 6.78 h (SD = 0.79) per focal participant. An unaffiliated female adult of Sango was engaged in parenting Sakura as much as Sango. Given that Sakura was in lesser proximity to Sango than Daiya, Sakura's departures from her mother and her ability to gesture requests might have enabled non-kin adults to provide her care. PMID:25200656

  14. Dicephalus Parapagus Conjoined Twins Diagnosed by First-Trimester Ultrasound

    PubMed Central

    Ikeda, Toshiyuki; Yakubo, Kazumi

    2016-01-01

    Conjoined twins are a rare phenomenon, occurring in 1% of monochorionic twin gestation, with an incidence of 1 : 50 000 to 1 : 100 000. Many conjoined twins have abnormalities incompatible with life, so early prenatal diagnosis is very important for optimal management of both pregnancy and delivery. We report a case of dicephalus parapagus conjoined twins, sharing a single heart, diagnosed at 12 weeks' gestation. With early ultrasound diagnosis, we were able to provide appropriate and timely prenatal counseling to the family. PMID:27366336

  15. Different Origin of Auditory and Phonological Processing Problems in Children with Language Impairment: Evidence from a Twin Study.

    ERIC Educational Resources Information Center

    Bishop, D. V. M.; Bishop, Sonia J.; Bright, Peter; James, Cheryl; Delaney, Tom; Tallal, Paula

    1999-01-01

    A study involving 55 children with a language impairment and 76 with normal language investigated the heritability of auditory processing impairment in same-sex twins (ages 7 to 13, selected from a sample of 37 pairs). Although correlations between co-twins were high, lack of significant difference between monozygotic and dizygotic twins suggested…

  16. Association of maternal and nutrient supply line factors with DNA methylation at the imprinted IGF2/H19 locus in multiple tissues of newborn twins.

    PubMed

    Loke, Yuk Jing; Galati, John C; Morley, Ruth; Joo, Eric Ji-Hoon; Novakovic, Boris; Li, Xin; Weinrich, Blaise; Carson, Nicole; Ollikainen, Miina; Ng, Hong-Kiat; Andronikos, Roberta; Aziz, Nur Khairunnisa Abdul; Saffery, Richard; Craig, Jeffrey M

    2013-10-01

    Epigenetic events are crucial for early development, but can be influenced by environmental factors, potentially programming the genome for later adverse health outcomes. The insulin-like growth factor 2 (IGF2)/H19 locus is crucial for prenatal growth and the epigenetic state at this locus is environmentally labile. Recent studies have implicated maternal factors, including folate intake and smoking, in the regulation of DNA methylation at this locus, although data are often conflicting in the direction and magnitude of effect. Most studies have focused on single tissues and on one or two differentially-methylated regions (DMRs) regulating IGF2/H19 expression. In this study, we investigated the relationship between multiple shared and non-shared gestational/maternal factors and DNA methylation at four IGF2/H19 DMRs in five newborn cell types from 67 pairs of monozygotic and 49 pairs of dizygotic twins. Data on maternal and non-shared supply line factors were collected during the second and third trimesters of pregnancy and DNA methylation was measured via mass spectrometry using Sequenom MassArray EpiTyper analysis. Our exploratory approach showed that the site of umbilical cord insertion into the placenta in monochorionic twins has the strongest positive association with methylation in all IGF2/H19 DMRs (p<0.05). Further, evidence for tissue- and locus-specific effects were observed, emphasizing that responsiveness to environmental exposures in utero cannot be generalized across genes and tissues, potentially accounting for the lack of consistency in previous findings. Such complexity in responsiveness to environmental exposures in utero has implications for all epigenetic studies investigating the developmental origins of health and disease. PMID:23917818

  17. Twinship as a resource: zygosity- and gender-based comparison of twins' attitudes toward twinship.

    PubMed

    Hegedűs, Rita; Pári, András; Drjenovszky, Zsófia; Kónya, Hanna

    2014-10-01

    Aiming to perform the first sociological survey of Hungarian twins, our main question was whether being a twin has positive consequences on one's life. Adult twins completed our questionnaire at three Hungarian summer twin festivals, in hospitals during medical twin studies, and on some websites online. Data represent 140 twin pairs (mean age: 38.2 ± 14.6 years). We employed some indices for measuring the resource nature of twinship. Three main types of benefits were distinguished: profit of attraction, as 'material capital'; the easier obtainability of cultural goods when twins take part in it, as 'cultural capital'; and positive aspects of an a priori existing dyadic relation, as 'relational capital'. We were interested in the difference among types of twins regarding advantages. We paid special attention to the five groups of twins derived from gender and zygosity (i.e., monozygotic females, monozygotic males, dizygotic females, dizygotic males, opposite-sex pairs). Our analysis showed that Hungarian twins involved in our research basically enjoy their twinship; during their lives they used and still make use of different benefits given by it. In our twin samples, women had more advantages from being a twin than men. Significant differences could be observed on all indicators between monozygotic and dizygotic twins. PMID:25111726

  18. Prenatal diagnosis of dicephalic parapagus conjoined twins.

    PubMed

    Camuzcuoglu, Hakan; Toy, Harun; Vural, Mehmet; Cece, Hasan; Aydin, Halef

    2010-03-01

    Dicephalic parapagus is a rare anomaly of monochorionic twinning. We present prenatal diagnosis of this anomaly with ultrasonography and magnetic resonance imaging. She was at the 19th week of gestation. Even if earlier diagnosis is possible, this was her first examination unfortunately. Baby had two head and a common trunk. This is one of the rarest twinning. Termination of pregnancy is performed and baby is delivered by cesarean section. Imaging findings of the case are illustrated and discussed with the autopsy findings. PMID:19714344

  19. Twin-to-Twin Transfusion Syndrome

    PubMed Central

    Mahieu-Caputo, Dominique; Dommergues, Marc; Delezoide, Anne-Lise; Lacoste, Mireille; Cai, Yi; Narcy, Françoise; Jolly, Dominique; Gonzales, Marie; Dumez, Yves; Gubler, Marie-Claire

    2000-01-01

    The twin-to-twin transfusion syndrome (TTS) results from an unbalanced blood supply through placental anastomoses in monochorionic twins. It induces growth restriction, renal tubular dysgenesis, and oliguria in the donor and visceromegaly and polyuria in the recipient. A better understanding of its pathophysiology could contribute to improving the management of TTS, which still carries a high perinatal mortality in both twins. As well as several other candidates, the renin-angiotensin system might be involved in TTS. To evaluate its role in the pathogenesis of the syndrome, we studied the kidneys of 21 twin pairs who died from TTS at 19 to 30 weeks, compared with 39 individuals in a control group, using light microscopy, immunohistochemistry, and in situ hybridization. The overexpression of the renin protein and transcript with frequent evidence of renin synthesis by mesangial cells was observed in the donor kidneys, presumably as a consequence of chronic renal hypoperfusion. This upregulation of renin synthesis might be beneficial to restore euvolemia. In severe cases of TTS, however, angiotensin-II-induced vasoconstriction acts as an additional deleterious factor by further reducing the renal blood flow in donors. In recipients, renin expression was virtually absent, possibly because it was down-regulated by hypervolemia. However, in addition to congestion and hemorrhagic infarction, there were severe glomerular and arterial lesions resembling those observed in polycythemia- or hypertension-induced microangiopathy. We speculate that fetal hypertension in the recipient might be partly mediated by the transfer of circulating renin produced by the donor, through the placental vascular shunts. PMID:10666392

  20. Unraveling Genetic and Environmental Components of Early Literacy: A Twin Study

    ERIC Educational Resources Information Center

    Bus, A. G.; Out, D.

    2009-01-01

    Even though the acquisition of early literacy skills obviously depends on stimuli and incentives in children's environment we may expect that genes define the constraints for acquiring some or all early literacy skills. Therefore behavior genetic analyses were carried out on twin data including 27 identical and 39 same sex dizygotic twins, 4 years…

  1. Familial Resemblance for Measures of Reading Performance in Families of Reading-Disabled and Control Twins.

    ERIC Educational Resources Information Center

    Alarcon, Maricela; And Others

    1994-01-01

    Finds that parent-offspring resemblance in families of reading-disabled probands does not differ substantially from that in families of controls; and correlations and regressions for monozygotic twins are greater than those for dizygotic twins, suggesting that individual differences in reading achievement are due in part to heritable influences.…

  2. Brief Report: On the Concordance Percentages for Autistic Spectrum Disorder of Twins

    ERIC Educational Resources Information Center

    Bohm, Henry V.; Stewart, Melbourne G.

    2009-01-01

    In the development of genetic theories of Autistic Spectrum Disorder (ASD) various characteristics of monozygotic (MZ) and dizygotic (DZ) twins are often considered. This paper sets forth a possible refinement in the interpretation of the MZ twin concordance percentages for ASD underlying such genetic theories, and, drawing the consequences from…

  3. Twin Study on Heritability of Activity, Attention, and Impulsivity as Assessed by Objective Measures

    ERIC Educational Resources Information Center

    Heiser, Philip; Heinzel-Gutenbrunner, Monika; Frey, Joachim; Smidt, Judith; Grabarkiewicz, Justyna; Friedel, Susann; Kuhnau, Wolfgang; Schmidtke, Jorg; Remschmidt, Helmut; Hebebrand, Johannes

    2006-01-01

    Objective: The purpose of this study was to assess heritability of activity, attention, and impulsivity by comparing young monozygotic (MZ) twins with dizygotic (DZ) twins using objective measures. Method: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. Seventeen MZ and 12 same…

  4. The Equal Environments Assumption of Classical Twin Studies May Not Hold

    ERIC Educational Resources Information Center

    Richardson, Ken; Norgate, Sarah

    2005-01-01

    The classical twin method -- comprising comparisons of monozygotic (MZ) and dizygotic (DZ) twins -- in the domain of cognitive abilities and attainments has led to wide acceptance of results suggesting a large amount of additive genetic variance, with far-reaching implications both for the nature of future studies on the causes of cognitive…

  5. Dogs discriminate identical twins.

    PubMed

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously. PMID:21698282

  6. Dogs Discriminate Identical Twins

    PubMed Central

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously. PMID:21698282

  7. Peer Network Overlap in Twin, Sibling, and Friend Dyads

    ERIC Educational Resources Information Center

    McGuire, Shirley; Segal, Nancy L.

    2013-01-01

    Research suggests that sibling–peer connections are important for understanding adolescent problem behaviors. Using a novel behavioral genetic design, the current study investigated peer network overlap in 300 child–child pairs (aged 7-13 years) in 5 dyad types: monozygotic (MZ), dizygotic twins, full siblings (FSs), friend pairs, and virtual…

  8. Selective Reduction Using Intravascular Potassium Chloride Injection after Laser Surgery for Twin-Twin Transfusion Syndrome.

    PubMed

    Chmait, Ramen H; Kontopoulos, Eftichia V; Jackson, Marc; Horenstein, Janet; Timor-Tritsch, Ilan; Quintero, Rubén A

    2016-01-01

    Selective reduction (SR) via intravascular potassium chloride (KCl) injection is contraindicated in monochorionic twins due to the presence of placental vascular communications, which may serve as a conduit for inter-twin passage of KCl or allow exsanguination of the living twin into the demised twin. After successful selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS), the twins' circulatory systems are rendered independent. Theoretically, intravascular KCl injection into one twin after successful SLPCV should not result in passage of the feticidal agent nor cause hemodynamic alterations in the co-twin. We describe 3 cases of 1,069 patients (0.3%) that underwent SLPCV for TTTS between 2003 and 2013 and subsequent SR. SLPCV was successfully completed at 180, 226, and 230 weeks' gestational age for Quintero stages III, IV, and III TTTS, respectively. SR via intravascular KCl injection was later performed at maternal request due to the risk of neurological compromise in one twin at 226, 254, and 236 weeks' gestational age. All co-twins survived after SR, and no neurological sequelae were suspected after birth. Further study is necessary before SR can be routinely considered after laser surgery for TTTS. PMID:26067899

  9. Zygosity of twins: is it time for a new terminology?

    PubMed

    Oleszczuk, J J; Machin, G A; Keith, D M; Keith, L G

    2000-11-01

    The term zygosity reflects the origin of twins--when twins are monozygotic, they are derived from a single fertilized ovum; when twins are dizygotic--the come from two fertilized ova. Zygosity assessment seemed straightforward 50 years ago. Currently, as more information and more technology becomes available, zygosity testing becomes a real problem. It is important to realize the importance of correct zygosity testing not only in the antepartum care of the pregnant mother, but more importantly--during the whole lifetime of twin individuals. This paper discusses revolving around zygosity, methods of assessment, their limitations and proposes new terminology which incorporates the recent knowledge about early human development. PMID:11216134

  10. Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis

    PubMed Central

    Cheong-See, Fiona; Schuit, Ewoud; Arroyo-Manzano, David; Khalil, Asma; Barrett, Jon; Joseph, K S; Asztalos, Elizabeth; Hack, Karien; Lewi, Liesbeth; Lim, Arianne; Liem, Sophie; Norman, Jane E; Morrison, John; Combs, C Andrew; Garite, Thomas J; Maurel, Kimberly; Serra, Vicente; Perales, Alfredo; Rode, Line; Worda, Katharina; Nassar, Anwar; Aboulghar, Mona; Rouse, Dwight; Thom, Elizabeth; Breathnach, Fionnuala; Nakayama, Soichiro; Russo, Francesca Maria; Robinson, Julian N; Dodd, Jodie M; Newman, Roger B; Bhattacharya, Sohinee; Tang, Selphee; Mol, Ben Willem J; Thilaganathan, Basky; Thangaratinam, Shakila

    2016-01-01

    Objective To determine the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies. Design Systematic review and meta-analysis. Data sources Medline, Embase, and Cochrane databases (until December 2015). Review methods Databases were searched without language restrictions for studies of women with uncomplicated twin pregnancies that reported rates of stillbirth and neonatal outcomes at various gestational ages. Pregnancies with unclear chorionicity, monoamnionicity, and twin to twin transfusion syndrome were excluded. Meta-analyses of observational studies and cohorts nested within randomised studies were undertaken. Prospective risk of stillbirth was computed for each study at a given week of gestation and compared with the risk of neonatal death among deliveries in the same week. Gestational age specific differences in risk were estimated for stillbirths and neonatal deaths in monochorionic and dichorionic twin pregnancies after 34 weeks’ gestation. Results 32 studies (29 685 dichorionic, 5486 monochorionic pregnancies) were included. In dichorionic twin pregnancies beyond 34 weeks (15 studies, 17 830 pregnancies), the prospective weekly risk of stillbirths from expectant management and the risk of neonatal death from delivery were balanced at 37 weeks’ gestation (risk difference 1.2/1000, 95% confidence interval −1.3 to 3.6; I2=0%). Delay in delivery by a week (to 38 weeks) led to an additional 8.8 perinatal deaths per 1000 pregnancies (95% confidence interval 3.6 to 14.0/1000; I2=0%) compared with the previous week. In monochorionic pregnancies beyond 34 weeks (13 studies, 2149 pregnancies), there was a trend towards an increase in stillbirths compared with neonatal deaths after 36 weeks, with an additional 2.5 per 1000 perinatal deaths, which was not significant (−12.4 to 17.4/1000; I2=0%). The rates of neonatal morbidity showed a consistent reduction with increasing

  11. Prevalence and risk of Down syndrome in monozygotic and dizygotic multiple pregnancies in Europe: implications for prenatal screening

    PubMed Central

    Boyle, B; Morris, JK; McConkey, R; Garne, E; Loane, M; Addor, MC; Gatt, M; Haeusler, M; Latos-Bielenska, A; Lelong, N; McDonnell, R; Mullaney, C; O’Mahony, M; Dolk, H

    2014-01-01

    Objective To determine risk of Down syndrome (DS) in multiple relative to singleton pregnancies, and compare prenatal diagnosis rates and pregnancy outcome. Design Population-based prevalence study based on EUROCAT congenital anomaly registries. Setting Eight European countries. Population 14.8 million births 1990–2009; 2.89% multiple births. Methods DS cases included livebirths, fetal deaths from 20 weeks, and terminations of pregnancy for fetal anomaly (TOPFA). Zygosity is inferred from like/unlike sex for birth denominators, and from concordance for DS cases. Main outcome measures Relative risk (RR) of DS per fetus/baby from multiple versus singleton pregnancies and per pregnancy in monozygotic/dizygotic versus singleton pregnancies. Proportion of prenatally diagnosed and pregnancy outcome. Statistical analysis Poisson and logistic regression stratified for maternal age, country and time. Results Overall, the adjusted (adj) RR of DS for fetus/babies from multiple versus singleton pregnancies was 0.58 (95% CI 0.53–0.62), similar for all maternal ages except for mothers over 44, for whom it was considerably lower. In 8.7% of twin pairs affected by DS, both co-twins were diagnosed with the condition. The adjRR of DS for monozygotic versus singleton pregnancies was 0.34 (95% CI 0.25–0.44) and for dizygotic versus singleton pregnancies 1.34 (95% CI 1.23–1.46). DS fetuses from multiple births were less likely to be prenatally diagnosed than singletons (adjOR 0.62 [95% CI 0.50–0.78]) and following diagnosis less likely to be TOPFA (adjOR 0.40 [95% CI 0.27–0.59]). Conclusions The risk of DS per fetus/baby is lower in multiple than singleton pregnancies. These estimates can be used for genetic counselling and prenatal screening. PMID:24495335

  12. NOTE: Thrombosis of anastomoses may affect the staging sequence of twin twin transfusion syndrome

    NASA Astrophysics Data System (ADS)

    van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; van Gemert, Martin J. C.

    2008-03-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. Supported in part by the European Community Euro-twin-2-twin project (JPHMvdW) and by the National Institutes of Health, grant HL40899 (MGR).

  13. Inspection Time and Cognitive Abilities in Twins Aged 7 to 17 Years: Age-Related Changes, Heritability and Genetic Covariance

    ERIC Educational Resources Information Center

    Edmonds, Caroline J.; Isaacs, Elizabeth B.; Visscher, Peter M.; Rogers, Mary; Lanigan, Julie; Singhal, Atul; Lucas, Alan; Gringras, Paul; Denton, Jane; Deary, Ian J.

    2008-01-01

    We studied the age-related differences in inspection time and multiple cognitive domains in a group of monozygotic (MZ) and dizygotic (DZ) twins aged 7 to 17 years. Data from 111 twin pairs and 19 singleton siblings were included. We found clear age-related trends towards more efficient visual information processing in older participants. There…

  14. Evidence for higher heritability of somatotype compared to body mass index in female twins.

    PubMed

    Reis, Victor Machado; Machado, João V; Fortes, Marcos S; Fernandes, Paula Roquetti; Silva, António José; Dantas, Paulo Silva; Filho, José Fernandes

    2007-01-01

    The influence of genetics on human physique and obesity has been addressed by the literature. Evidence for heritability of anthropometric characteristics has been previously described, mainly for the body mass index (BMI). However, few studies have investigated the influence of genetics on the Heath-Carter somatotype. The aim of the present study was to assess the heritability of BMI and somatotype (endomorphy, mesomorphy, and ectomorphy) in a group of female monozygotic and dizygotic twins from childhood to early adulthood. A total of 28 females aged from 7 to 19 years old were studied. The group included 5 monozygotic and 9 dizygotic pairs of twins. The heritability was assessed by the twin method (h(2)). The anthropometric measures and somatotype were assessed using standard validated procedures. Significant differences between monozygotic and dizygotic pairs of twins were found for height, endomorphy, ectomorphy, and mesomorphy, and the heritability for these measures was high (h(2) between 0.88 and 0.97). No significant differences were found between monozygotic and dizygotic twins for weight, and the BMI and the heritability indexes were lower for these measures (respectively 0.42 and 0.52). The results of the present study have indicated that the somatotype may be more sensible to genetic influences than the BMI in females. PMID:17283387

  15. Twin-twin transfusion syndrome: neurodevelopment of infants treated with laser surgery.

    PubMed

    Campos, Denise; Arias, Amabile V; Campos-Zanelli, Thatiane M; Souza, Daniela S; Santos Neto, Orlando G Dos; Peralta, Cleisson Fabio A; Guerreiro, Marilisa M

    2016-04-01

    Objective To assess the neurodevelopmental functions of survivors of twin-twin transfusion syndrome (TTTS) treated by fetoscopic laser coagulation (FLC), during the first year of life, comparing them to a control group; and to verify the influence of specific variables on neurodevelopment. Method This was a prospective, longitudinal study. The sample comprised 33 monochorionic diamniotic twins who underwent FLC for treatment of TTTS and 22 full-term infants of single-fetus pregnancies. Bayley Scales of Infant and Toddler Development Screening Test were used for evaluation. Prenatal, perinatal and postnatal information were obtained. Results There was an increased frequency of infants in the TTTS group with inadequate performance compared to the control group. The identified variables (fetal donor, low economic income and cardiorespiratory disease) negatively impacted expressive communication and fine motor skills. Conclusion Although through follow-up is recommended in all TTTS survivors, particular attention is required for the high-risk group as defined in this study. PMID:27097004

  16. Conjoined twins.

    PubMed

    Pearce, K M; Mohler, C P; Housel, D; Schipul, A H; Crosby, W M

    1995-06-01

    Conjoined twins, otherwise known as Siamese twins, have fascinated physicians and laymen alike for centuries. The minimal diagnostic criteria for conjoined twins is the fusion of some portion of mononuclear or monozygotic twins. PMID:7629608

  17. The value of twins in epigenetic epidemiology.

    PubMed

    Bell, Jordana T; Saffery, Richard

    2012-02-01

    During past decades, twin studies have played an important role in genetic epidemiology studies of complex traits. The strength of twin studies lies in the ability to disentangle genetic and environmental factors that contribute to a phenotype, by comparing genetically identical monozygotic twins to dizygotic twins, who share on average 50% of genetic variants. Twin studies now offer the opportunity to study epigenetic variation across the genome with two aims. First, twin studies can improve our understanding of the factors regulating epigenetic variability by assessing the heritability of epigenetic variants. Secondly, the use of twins in epigenetic research is increasingly recognized as an important approach to help unravel the complexities associated with human development and disease. The strategic use of identical twins discordant for complex disease has revealed the importance of linking epigenetic disruption to the disease-associated risk in humans. Lastly, we also discuss the possibility that epigenetic effects on disease may in part explain some of the missing heritability in genome-wide association studies. The study of human epigenetic factors in twins can inform the role of genetics, as well as in utero and postnatal environments to the establishment, maintenance and functional consequences of human epigenome variation. PMID:22253312

  18. Germ cells and ova in dysgenetic gonads of a 46-XY female dizygotic twin.

    PubMed

    Cussen, L J; MacMahon, R A

    1979-04-01

    The frequency of germ cell neoplasms in girls with 46-XY gonadal dysgenesis suggests that germ cells may persist in the dysgenetic gonads for many years. A phenotypic female infant with a karyotype of 46-XY in blood, skin, and gonads had a few ova in primordial follicles and numerous germ cells in her dysgenetic gonads at the age of 3 months. At 3 years and 10 months of age her gonads contained no primordial follicle and the only remaining germ cells were in a gonadoblastoma. We propose that germ cells are lost from dysgenetic gonads much more rapidly than from normal gonads, but that the rate of loss in patients with a karyotype of 46-XY may be less than the rate of loss in patients with a karyotype of 45-XO. PMID:433851

  19. Minimally Conjoined Omphalopagus Twins with a Body Stalk Anomaly.

    PubMed

    Maruyama, Hidehiko; Inagaki, Takeshi; Nakata, Yusei; Kanazawa, Akane; Iwasaki, Yuka; Sasaki, Kiyoshi; Nagai, Ryuhei; Kinoshita, Hiromi; Iwata, Jun; Kikkawa, Kiyoshi

    2015-10-01

    Introduction This report will discuss a case of minimally conjoined omphalopagus twins (MCOTs) with a body stalk anomaly (BSA). Case Report We experienced monochorionic diamniotic (MD) twins born at 31 weeks. One infant was suspicious of BSA before birth, and another infant was normal. But normal infant had anal atresia with small intestine which was inserted behind the umbilicus. Twins had very short common umbilicus and infant with BSA had intestinal conjunction, two appendixes at the site of the colon, and a blind-ending colon. We diagnosed MCOTs. Discussion On the basis of the Spencer hypothesis, the etiology of MCOTs was that MD twins shared a yolk sac. However, this could not explain the presence of a BSA. It is necessary to consider the possible reasons for a singleton BSA. In addition, intestinal fusion occurred unequally in this case, although two appendixes were found in the same place, which might have occurred because of the balanced fusion. PMID:26495169

  20. Minimally Conjoined Omphalopagus Twins with a Body Stalk Anomaly

    PubMed Central

    Maruyama, Hidehiko; Inagaki, Takeshi; Nakata, Yusei; Kanazawa, Akane; Iwasaki, Yuka; Sasaki, Kiyoshi; Nagai, Ryuhei; Kinoshita, Hiromi; Iwata, Jun; Kikkawa, Kiyoshi

    2015-01-01

    Introduction This report will discuss a case of minimally conjoined omphalopagus twins (MCOTs) with a body stalk anomaly (BSA). Case Report We experienced monochorionic diamniotic (MD) twins born at 31 weeks. One infant was suspicious of BSA before birth, and another infant was normal. But normal infant had anal atresia with small intestine which was inserted behind the umbilicus. Twins had very short common umbilicus and infant with BSA had intestinal conjunction, two appendixes at the site of the colon, and a blind-ending colon. We diagnosed MCOTs. Discussion On the basis of the Spencer hypothesis, the etiology of MCOTs was that MD twins shared a yolk sac. However, this could not explain the presence of a BSA. It is necessary to consider the possible reasons for a singleton BSA. In addition, intestinal fusion occurred unequally in this case, although two appendixes were found in the same place, which might have occurred because of the balanced fusion. PMID:26495169

  1. Imperfect twinning: a clinical and ethical dilemma

    PubMed Central

    Denardin, Daniela; Telles, Jorge Alberto B.; Betat, Rosilene da Silveira; Fell, Paulo Renato K.; da Cunha, André Campos; Targa, Luciano Vieira; Zen, Paulo Ricardo G.; Rosa, Rafael Fabiano M.

    2013-01-01

    OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. DATA SYNTHESIS: The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family. PMID:24142323

  2. Sources of Human Psychological Differences: The Minnesota Study of Twins Reared Apart.

    ERIC Educational Resources Information Center

    Bouchard, Thomas J., Jr.; And Others

    1990-01-01

    Described is an ongoing study of monozygotic and dizygotic twins, separated in infancy and reared apart. Discussed are the procedures and results of this study with interpretations of the results. The effects of parenting, education, and other interventions are considered. (CW)

  3. Longitudinal Twin Study of Early Literacy Development: Preschool and Kindergarten Phases

    ERIC Educational Resources Information Center

    Byrne, Brian; Wadsworth, Sally; Corley, Robin; Samuelsson, Stefan; Quain, Peter; DeFries, John C.; Willcutt, Erik; Olson, Richard K.

    2005-01-01

    We conducted behavior?genetic analyses of kindergarten reading, spelling, phonological awareness, rapid naming, and spoken sentence processing in 172 pairs of monozygotic and 153 pairs of same-sex dizygotic twin kindergarten children sampled in the United States and Australia. We also modeled progress from preschool to kindergarten in…

  4. Sensory Motor and Functional Skills of Dizygotic Twins: One with Smith-Magenis Syndrome and a Twin Control

    ERIC Educational Resources Information Center

    Smith, Michaele R.; Hildenbrand, Hanna; Smith, Ann C. M.

    2009-01-01

    Smith-Magenis syndrome (SMS), the result of an interstitial deletion within chromosome 17p11.2, is a disorder that may include minor dysmorphic features, brachydactyly, short stature, hypotonia, speech delays, cognitive deficits, signs of peripheral neuropathy, scoliosis, and neurobehavioral problems including sleep disturbances and maladaptive…

  5. Methylation matters? Decreased methylation status of genomic DNA in the blood of schizophrenic twins.

    PubMed

    Bönsch, Dominikus; Wunschel, Michael; Lenz, Bernd; Janssen, Gesa; Weisbrod, Matthias; Sauer, Heinrich

    2012-08-15

    Studies of schizophrenia inheritance in identical twins show a concordance of about 50%, which supports an epigenetic model. In our present study we investigated methylation of genomic DNA and promoter methylation of Reelin and SOX10 genes in peripheral blood of twins suffering from schizophrenia. Global DNA methylation was reduced (52.3%) in schizophrenic twins if compared with healthy control twins (65.7%). The reduced methylation was significant in males only. We also found a similar hypomethylation in the non-affected twins of discordant pairs and a mixed group of psychiatric controls. In discordant twins there was a relative hypermethylation of the SOX10 promoter. Within-pair-difference of methylation of Reelin promoter was significantly lower in monozygotic twins than in dizygotic twins. PMID:23102571

  6. Twins discordant for myositis and systemic lupus erythematosus show markedly enriched autoantibodies in the affected twin supporting environmental influences in pathogenesis

    PubMed Central

    2014-01-01

    Background Studies of twin pairs discordant for autoimmune conditions provide a unique opportunity to explore contributing factors triggered by complex gene-environment interactions. Methods In this cross-sectional study, thirty-one monozygotic or dizygotic twin pairs discordant for myositis or systemic lupus erythematosus (SLE), along with matched healthy controls were evaluated for antibodies against a panel of 21 autoantigens. Results Autoantibody profiling revealed that 42% of the affected twins showed significant seropositivity against autoantigens in the panel. In many of these affected twins, but none of healthy controls, there were high levels of autoantibodies detected against two or more autoantigens commonly seen in systemic autoimmune diseases including Ro52, Ro60, RNP-70 K and/or RNP-A. In contrast, only 10% (3/31) of the unaffected twins showed seropositivity and these immunoreactivities were against single autoantigens not seen in systemic autoimmune diseases. While no significant differences in autoantibodies were detected between the affected or unaffected twins against thyroid peroxidase, transglutaminase and several cytokines, 23% of the affected twins with myositis showed autoantibodies against the gastric ATPase. Analysis of the monozygotic twins separately also revealed a higher frequencies of autoantibodies in the affected twins compared to the unaffected twins (P = 0.046). Lastly, clinical analysis of both the affected monozygotic and dizygotic twins revealed that the autoantibody seropositive affected twins had a greater global disease activity score compared to seronegative affected twins (P = 0.019). Conclusion The findings of significantly more autoantibodies in the affected twins with myositis and SLE compared to the unaffected twins are consistent with potential non-genetic factors playing a role in autoantibody production and pathogenesis of these autoimmune disorders. PMID:24602337

  7. Peer reports of adaptive behavior in twins and singletons: is twinship a risk or an advantage?

    PubMed

    Pulkkinen, Lea; Vaalamo, Inka; Hietala, Risto; Kaprio, Jaakko; Rose, Richard J

    2003-04-01

    We compared twins to their gender-matched singleton classmates in peer-assessed behavioral adjustment. Our samples include 1874 11- to 12-year-old Finnish twins (687 monozygotic, MZ; 610 same-sex dizygotic, SSDZ; 577 opposite-sex dizygotic, OSDZ) and their 23,200 non-twin classmates. Data were collected using a 30-item Multidimensional Peer Nomination Inventory containing three factors and their subscales. We found twin-singleton differences: classmates rated twin girls and boys higher than gender-matched singletons in Adaptive Behaviors (constructive, compliant, and socially active behavior), and those effects were particularly evident among OSDZ twins for assessments of social interaction, popularity, and leadership. We found no evidence that individual twins differ from singletons in Externalizing (hyperactivity-impulsivity, inattention, aggression) or Internalizing Problem Behaviors (depressive symptoms, social anxiety). Nor did we find systematic differences between MZ and SSDZ twins. Among both twins and singletons, boys exceeded girls in Externalizing, and girls exceeded boys in Internalizing Problem Behaviors. Results suggest that a twinship forms a positive developmental environment for socioemotional behavior, particularly among OSDZ twins. PMID:12723997

  8. Twins and the paradox of dental-age estimations: a caution for researchers and clinicians.

    PubMed

    Pechníková, M; De Angelis, D; Gibelli, D; Vecchio, V; Cameriere, R; Zeqiri, B; Cattaneo, C

    2014-08-01

    The biological age difference among twins is frequently an issue in studies of genetic influence on various dental features, particularly dental development. The timing of dental development is a crucial issue also for many clinicians and researchers. The aim of this study was therefore to verify within groups of twins how dental development differs, by applying Demirjian's method, Mincer's charts of development of third molars and two of Cameriere's methods for dental age estimation, which are among the most popular methods both in the clinical and the forensic scenario. The sample consisted of 64 twin pairs: 21 monozygotic, 30 dizygotic same-sex and 13 dizygotic opposite-sex with an age range between 5.8 and 22.6 years. Dental age was determined from radiographs using the mentioned methods. Results showed that dental age of monozygotic twins is not identical even if they share all their genes. The mean intra-pair difference of monozygotic pairs was low and similar to the difference in dizygotic same-sex twins; the maximum difference between monozygotic twins, however, was surprisingly large (nearly two years). This should lead to some circumspection in the interpretation of systematic estimations of dental age both in the clinical and forensic scenario. PMID:24951409

  9. Future Directions in the Management of Twin-to-Twin Transfusion Syndrome.

    PubMed

    Cincotta, Robert; Kumar, Sailesh

    2016-06-01

    Twin-to-twin transfusion syndrome (TTTS) is the major complication of monochorionic (MC) pregnancy. The outcomes of this condition have been significantly improved after the introduction and widespread uptake of fetoscopic laser ablation over the last decade. However, there is still a significant fetal loss rate and morbidity associated with this condition. Improvements in the management of TTTS will require improvements in many areas. They are likely to involve refinements in the prediction of the disease and clarification of the optimum frequency of surveillance and monitoring. Improvements in training for fetoscopic surgery as well as in the technique of fetoscopic laser ablation may lead to better outcomes. New technologies as well as a better understanding of the pathophysiology of TTTS may lead to adjuvant medical therapies that may also improve short- and long-term results. PMID:27125296

  10. Twin-to-twin transfusion syndrome

    MedlinePlus

    Twin-to-twin transfusion syndrome is a rare condition that occurs only in identical twins while they are in the womb. ... Twin-to-twin transfusion syndrome (TTTS) occurs when the blood supply of 1 twin moves to the ...

  11. Twin pregnancy in a patient of chronic myeloid leukemia on imatinib therapy.

    PubMed

    Meera, V; Jijina, Farah; Shrikande, Mitu; Madkaikar, Manisha; Ghosh, K

    2008-10-01

    Imatinib is a tyrosine kinase inhibitor and is now used regularly in chronic myeloid leukaemia therapy in chronic phase with great success. This drug due its very nature of action is suspected to be teratogenic hence the patients are counseled not to get pregnant while on this drug. However in world literature few normal pregnancies have been reported in patients on Imatinib therapy, though no twin pregnancy has been reported on this medication. We report here the birth of normal mono-ovular mono-chorionic twin while the patient is on imatinib during conception and early pregnancy for chronic myeloid leukaemia. PMID:18420270

  12. Genetic and environmental contributions to pro-social attitudes: a twin study of social responsibility.

    PubMed Central

    Rushton, J. Philippe

    2004-01-01

    Although 51 twin and adoption studies have been performed on the genetic architecture of antisocial behaviour, only four previous studies have examined a genetic contribution to pro-social behaviour. Earlier work by the author with the University of London Institute of Psychiatry Adult Twin Register found that genes contributed approximately half of the variance to measures of self-report altruism, empathy, nurturance and aggression, including acts of violence. The present study extends those results by using a 22-item Social Responsibility Questionnaire with 174 pairs of monozygotic twins and 148 pairs of dizygotic twins. Forty-two per cent of the reliable variance was due to the twins' genes, 23% to the twins' common environment and the remainder to the twins' non-shared environment. PMID:15615684

  13. Fetal Brain Injury in Survivors of Twin Pregnancies Complicated by Demise of One Twin: A Review.

    PubMed

    Mackie, Fiona L; Morris, R Katie; Kilby, Mark D

    2016-06-01

    Perinatal mortality is increased considerably in multiple pregnancies compared to singleton pregnancies, with single intrauterine fetal demise (sIUFD) presenting a rare but unique perinatal problem. Monochorionic pregnancies are at particular risk of sIUFD due to bidirectional inter-twin placental vascular anastomoses. The resulting inter-twin blood flow can become unbalanced, causing acute and chronic inter-twin transfusion and profound anemia secondary to fetal exsanguination into the low-pressure circulation of the dead fetus. If the sIUFD occurs after 14 weeks' gestation it is believed to have the most significant effect on the continuing pregnancy as the co-twin is at increased risk of preterm delivery, long-term neurological complications, and death. This article will focus on fetal brain injury in the surviving co-twin in the case of sIUFD, as it is the most common kind of injury in sIUFD, and one which concerns parents and may be the basis for terminating the pregnancy. We will outline how these brain injuries are thought to occur and describe potential pathophysiological mechanisms. We will discuss risk factors for brain injury in cases of sIUFD, including: chorionicity, cause of the sIUFD (spontaneous or secondary to an underlying pathological process such as twin-to-twin transfusion syndrome), gestation of delivery and how to prevent brain injury in the co-twin. We also review modes of imaging, discuss the difficulties in predicting the long-term outcome for co-twin survivors, and highlight the dearth of research in this area. PMID:27203608

  14. Twin concordance and sibling recurrence rates in multiple sclerosis

    PubMed Central

    Willer, C. J.; Dyment, D. A.; Risch, N. J.; Sadovnick, A. D.; Ebers, G. C.

    2003-01-01

    Size and ascertainment constraints often limit twin studies to concordance comparisons between identical and fraternal twins. Here we report the final results of a longitudinal, population-based study of twins with multiple sclerosis (MS) in Canada. Bias was demonstrably minimized, and an estimated 75% of all Canadian MS twin pairs were ascertained, giving a sample sufficiently large (n = 370) to permit additional informative comparisons. Twinning was not found to affect prevalence, and twins with MS did not differ from nontwins for DR15 allele frequency nor for MS risk to their siblings. Probandwise concordance rates of 25.3% (SE ± 4.4) for monozygotic (MZ), 5.4% (±2.8) for dizygotic (DZ), and 2.9% (±0.6) for their nontwin siblings were found. MZ twin concordance was in excess of DZ twin concordance. The excess concordance in MZ was derived primarily from like-sexed female pairs with a probandwise concordance rate of 34 of 100 (34 ± 5.7%) compared with 3 of 79 (3.8 ± 2.8%) for female DZ pairs. We did not demonstrate an MZ/DZ difference in males, although the sample size was small. We observed a 2-fold increase in risk to DZ twins over nontwin siblings of twins, but the difference was not significant. PMID:14569025

  15. A twin study of computer anxiety in Turkish adolescents.

    PubMed

    Deryakulu, Deniz; Calışkan, Erkan

    2012-04-01

    The present study investigated computer anxiety within a sample of Turkish twins aged 10-18. A total of 185 twin-pairs participated in the study. Of the twins, 64 pairs (34.6 percent) were monozygotic (MZ) and 121 pairs (65.4 percent) were dizygotic (DZ). Of the 121 DZ twins, 54 pairs (44.63 percent) were same-sex twins and 67 pairs (55.37 percent) were opposite-sex twins. Computer anxiety was assessed using Computer Anxiety Rating Scale-Turkish Version (CARS-TV), one of the three main scales of "Measuring Technophobia Instruments" developed by Rosen and Weil. The results of paired t test comparisons showed no significant differences in MZ and same-sex DZ twin-pairs' levels of computer anxiety. On the other hand, a significant difference was found in opposite-sex DZ twin-pairs' level of computer anxiety. Interesting enough, males appeared to be more computer anxious than their female co-twins. In the present study, using Falconer's formula, heritability estimate for computer anxiety was derived from correlations based on MZ and DZ twins' mean scores on CARS-TV. The results showed that 57 percent of the variance in computer anxiety was from genetics and 41.5 percent was from nonshared environmental factors. Shared environmental influence, on the other hand, was very small and negligible. Interpretations of results and potential directions for future research are presented. PMID:22394420

  16. Proton MRS in twin pairs discordant for schizophrenia.

    PubMed

    Lutkenhoff, E S; van Erp, T G; Thomas, M A; Therman, S; Manninen, M; Huttunen, M O; Kaprio, J; Lönnqvist, J; O'Neill, J; Cannon, T D

    2010-03-01

    Proton magnetic resonance spectroscopy ((1)H MRS) neurometabolite abnormalities have been detected widely in subjects with and at risk for schizophrenia. We hypothesized that such abnormalities would be present both in patients with schizophrenia and in their unaffected twin siblings. We acquired magnetic resonance spectra (TR/TE=3000/30 ms) at voxels in the mesial prefrontal gray matter, left prefrontal white matter and left hippocampus in 14 twin pairs discordant for schizophrenia (2 monozygotic, 12 dizygotic), 13 healthy twin pairs (4 monozygotic, 9 dizygotic) and 1 additional unaffected co-twin of a schizophrenia proband. In the mesial prefrontal gray matter voxel, N-acetylaspartate (NAA), creatine+phosphocreatine (Cr), glycerophosphocholine+phosphocholine (Cho) and myo-inositol (mI) did not differ significantly between patients with schizophrenia, their unaffected co-twins or healthy controls. However, glutamate (Glu) was significantly lower in patients with schizophrenia (31%, percent difference) and unaffected co-twins (21%) than in healthy controls (collapsed across twin pairs). In the left hippocampus voxel, levels of NAA (23%), Cr (22%) and Cho (36%) were higher in schizophrenia patients compared with controls. Hippocampal NAA (25%), Cr (22%) and Cho (37%) were also significantly higher in patients than in their unaffected co-twins. Region-to-region differences in metabolite levels were also notable within all three diagnosis groups. These findings suggest that (1)H MRS neurometabolite abnormalities are present not only in patients with schizophrenia, but also in their unaffected co-twins. Thus, reduced mesial prefrontal cortical Glu and elevated hippocampal NAA, Cr and Cho may represent trait markers of schizophrenia risk and, when exacerbated, state markers of schizophrenia itself. PMID:18645571

  17. Erythroblastosis of the Donor Twin of Twin Anemia-Polycythemia Sequence.

    PubMed

    Takeuchi, Miharu; Maruyama, Hidehiko; Oura, Naoko; Kanazawa, Akane; Nakata, Yusei; Minami, Susumu; Kikkawa, Kiyoshi

    2016-08-01

    Twin anemia-polycythemia sequence (TAPS) is a group of disorders in monochorionic twins characterized by a large intertwin hemoglobin difference without amniotic fluid discordance. Reticulocyte count is used to diagnose this condition, but little is known about the role of erythroblasts, which are the prior stage of reticulocytes. In the present case of TAPS, the 25-yr-old Japanese mother showed no signs of oligohydramnios or polyhydramnios throughout gestation. The twins were born at 36 weeks and 6 days, weighing 2,648g and 1,994g. The intertwin hemoglobin difference in umbilical cord blood was (21.1-5.0=) 16.1g/dL and the donor twin showed signs of chronic anemia, including myocardial hypertrophy and pericardial effusion. Erythroblastosis of the donor twin was prolonged (53,088.5, 42,114.8 and 44,217.9/μL on days 0, 1 and 2, respectively). Erythroblastosis, which indicates chronic anemia, is also a good diagnostic indicator of TAPS. PMID:27549671

  18. A Twin Protection Effect? Explaining Twin Survival Advantages with a Two-Process Mortality Model

    PubMed Central

    2016-01-01

    Twin studies that focus on the correlation in age-at-death between twin pairs have yielded important insights into the heritability and role of genetic factors in determining lifespan, but less attention is paid to the biological and social role of zygosity itself in determining survival across the entire life course. Using data from the Danish Twin Registry and the Human Mortality Database, we show that monozygotic twins have greater cumulative survival proportions at nearly every age compared to dizygotic twins and the Danish general population. We examine this survival advantage by fitting these data with a two-process mortality model that partitions survivorship patterns into extrinsic and intrinsic mortality processes roughly corresponding to acute, environmental and chronic, biological origins. We find intrinsic processes confer a survival advantage at older ages for males, while at younger ages, all monozygotic twins show a health protection effect against extrinsic death akin to a marriage protection effect. While existing research suggests an increasingly important role for genetic factors at very advanced ages, we conclude that the social closeness of monozygotic twins is a plausible driver of the survival advantage at ages <65. PMID:27192433

  19. Why Accurate Knowledge of Zygosity is Important to Twins.

    PubMed

    Cutler, Tessa L; Murphy, Kate; Hopper, John L; Keogh, Louise A; Dai, Yun; Craig, Jeffrey M

    2015-06-01

    All same-sex dizygotic (DZ) twins and approximately one-third of monozygotic (MZ) twin pairs have separate placentas, making it impossible to use the number of placentas to determine zygosity. Zygosity determination is further complicated because incorrect assumptions are often made, such as that only DZ pairs have two placentas and that all MZ pairs are phenotypically identical. These assumptions, by twins, their families and health professionals, along with the lack of universal zygosity testing for same-sex twins, has led to confusion within the twin community, yet little research has been conducted with twins about their understanding and assumptions about zygosity. We aimed to explore and quantify understanding and assumptions about zygosity using twins attending an Australian twin festival. We recruited 91 twin pairs younger than 18 years of age and their parents, and 30 adult twin pairs who were all uncertain of their zygosity, to complete one pen and paper questionnaire and one online questionnaire about their assumed zygosity, reasons for their assumptions and the importance of accurate zygosity knowledge. Responses were compared with their true zygosity measured using a genetic test. We found a substantial proportion of parents and twins had been misinformed by their own parents or medical professionals, and that knowledge of their true zygosity status provided peace of mind and positive emotional responses. For these reasons we propose universal zygosity testing of same-sex twins as early in life as possible and an increase in education of medical professionals, twins and families of twins about zygosity issues. PMID:25851727

  20. Doppler assessment of fetal aortic isthmus flow in twin

    PubMed Central

    Lee, Soon Pyo; Lee, Chae Min; Jung, Sun Young; Park, Han Na

    2015-01-01

    Objective The purpose of this study was to investigate the aortic isthmus (AoI) flow difference between larger fetus and smaller fetus of twin; and to evaluate the predictive value of early diagnosis of hemodynamic change in twin growth. Methods This prospective study on 49 pairs of twin fetuses was performed to obtain AoI blood flow data. Cases with structural or chromosomal abnormalities and co-twin death were excluded. The interval from examination to delivery was within 4 weeks and 3 cases over 4 weeks interval were re-examined. Assessment of fetal AoI Doppler parameters were peak systolic velocity (PSV), end-diastolic velocity, times-averaged maximum velocities, pulsatility index (PI), and resistance index (RI). According to the direction of the diastolic flow in the AoI, antegrade and retrograde flow were made and was used to analyze the perinatal outcomes of each fetus. The predictive value of AoI Doppler parameters in predicting fetal growth was obtained by using ANOVA and logistic regression analysis of quantitative variables in each fetus of twins. Results There were significant differences in the gestational weeks at delivery, birth weight and the incidence of growth discordance over 20% or more between monochorionic twin and dichorionic twin. The AoI PI and RI were significantly higher in smaller fetus than in larger regardless of chorionicity. Retrograde flow was noted in 8 of 98 cases (8.2%) and the only one case was of the larger fetus and the others were smaller fetuses of twin. Significant correlations were found between the AoI PI and birthweight (P=0.018) and between the PSV and growth discordance (P=0.032). In monochorionic twin, linear correlation was shown between the AoI PI and birthweight (P=0.004) and between AoI PI and growth discordance (P=0.031). Also, the meaningful correlation between the PSV and birthweight (P=0.036) was found by using logistic regression analyses. Conclusion On the basis of our observation, AoI PI has revealed their

  1. [Adult twins].

    PubMed

    Charlemaine, Christiane

    2006-12-31

    This paper explores the deep roots of closeness that twins share in their youngest age and their effect on their destiny at the adult age. Psychologists believe the bond between twins begins in utero and develops throughout the twins' lives. The four patterns of twinship described show that the twin bond is determined by the quality of parenting that twins receive in their infancy and early childhood. Common problems of adult twins bring about difficulties to adapt in a non-twin world. The nature versus nurture controversy has taken on new life focusing on inter-twin differences and the importance of parent-child interaction as fundamental to the growth and development of personality. PMID:17352324

  2. Yoruba customs and beliefs pertaining to twins.

    PubMed

    Leroy, Fernand; Olaleye-Oruene, Taiwo; Koeppen-Schomerus, Gesina; Bryan, Elizabeth

    2002-04-01

    The Yoruba are an important ethnic group mainly occupying Southwestern Nigeria. Mainly for genetic reasons, this very large tribe happens to present the highest dizygotic twinning rate in the world (4.4 % of all maternities). The high perinatal mortality rate associated with such pregnancies has contributed to the integration of a special twin belief system within the African traditional religion of this tribe. The latter is based on the concept of a supreme deity called Olodumare or Olorun, assisted by a series of secondary gods (Orisha) while Yoruba religion also involves immortality and reincarnation of the soul based on the animistic cult of ancestors. Twins are therefore given special names and believed to detain special preternatural powers. In keeping with their refined artistic tradition, the Yoruba have produced numerous wooden statuettes called Ibejis that represent the souls of deceased newborn twins and are involved in elaborate rituals. Among Yoruba traditional beliefs and lore some twin-related themes are represented which are also found in other parts of the world. Basic features of the original Yoruba beliefs have found their way into the religious traditions of descendants of African slaves imported in the West Indies and in South America. PMID:11931691

  3. Decreased Brain and Placental Perfusion in Omphalopagus Conjoined Twins on Fetal MRI.

    PubMed

    Gorkem, Sureyya Burcu; Kutuk, Mehmet Serdar; Doganay, Selim; Gunes, Tamer; Yildiz, Karamehmet; Kucukaydin, Mustafa

    2016-01-01

    The aim of this study is to evaluate perfusional changes in brain and placenta of omphalopagus conjoined twins and to compare them with singleton fetuses by using diffusion weighted imaging and apparent diffusion coefficient. Fetal MRIs of 28-week-old omphalopagus conjoined twins with a shared liver with two separate gallbladders and portal and hepatic venous systems and three singleton fetuses with unilateral borderline ventriculomegaly at the same gestational week as control group were enrolled retrospectively. There was a significant decrease in ADC values of brain regions (p = 0.018) and placenta (p = 0.005) of conjoined twins compared to the control group. The decreased ADC values in placenta and brain regions in conjoined twins might be due to decreased placental perfusion compared to singleton pregnancy. Our results would be a keystone for future studies which will compare larger group of monochorionic multiple pregnancies with singleton pregnancies. PMID:27034830

  4. Developmental timing of mutations revealed by whole-genome sequencing of twins with acute lymphoblastic leukemia.

    PubMed

    Ma, Yussanne; Dobbins, Sara E; Sherborne, Amy L; Chubb, Daniel; Galbiati, Marta; Cazzaniga, Giovanni; Micalizzi, Concetta; Tearle, Rick; Lloyd, Amy L; Hain, Richard; Greaves, Mel; Houlston, Richard S

    2013-04-30

    Acute lymphoblastic leukemia (ALL) is the major pediatric cancer. At diagnosis, the developmental timing of mutations contributing critically to clonal diversification and selection can be buried in the leukemia's covert natural history. Concordance of ALL in monozygotic, monochorionic twins is a consequence of intraplacental spread of an initiated preleukemic clone. Studying monozygotic twins with ALL provides a unique means of uncovering the timeline of mutations contributing to clonal evolution, pre- and postnatally. We sequenced the whole genomes of leukemic cells from two twin pairs with ALL to comprehensively characterize acquired somatic mutations in ALL, elucidating the developmental timing of all genetic lesions. Shared, prenatal, coding-region single-nucleotide variants were limited to the putative initiating lesions. All other nonsynonymous single-nucleotide variants were distinct between tumors and, therefore, secondary and postnatal. These changes occurred in a background of noncoding mutational changes that were almost entirely discordant in twin pairs and likely passenger mutations acquired during leukemic cell proliferation. PMID:23569245

  5. Decreased Brain and Placental Perfusion in Omphalopagus Conjoined Twins on Fetal MRI

    PubMed Central

    Kutuk, Mehmet Serdar; Doganay, Selim; Gunes, Tamer; Yildiz, Karamehmet; Kucukaydin, Mustafa

    2016-01-01

    The aim of this study is to evaluate perfusional changes in brain and placenta of omphalopagus conjoined twins and to compare them with singleton fetuses by using diffusion weighted imaging and apparent diffusion coefficient. Fetal MRIs of 28-week-old omphalopagus conjoined twins with a shared liver with two separate gallbladders and portal and hepatic venous systems and three singleton fetuses with unilateral borderline ventriculomegaly at the same gestational week as control group were enrolled retrospectively. There was a significant decrease in ADC values of brain regions (p = 0.018) and placenta (p = 0.005) of conjoined twins compared to the control group. The decreased ADC values in placenta and brain regions in conjoined twins might be due to decreased placental perfusion compared to singleton pregnancy. Our results would be a keystone for future studies which will compare larger group of monochorionic multiple pregnancies with singleton pregnancies. PMID:27034830

  6. Use of a twin dataset to identify AMD-related visual patterns controlled by genetic factors

    NASA Astrophysics Data System (ADS)

    Quellec, Gwénolé; Abràmoff, Michael D.; Russell, Stephen R.

    2010-03-01

    The mapping of genotype to the phenotype of age-related macular degeneration (AMD) is expected to improve the diagnosis and treatment of the disease in a near future. In this study, we focused on the first step to discover this mapping: we identified visual patterns related to AMD which seem to be controlled by genetic factors, without explicitly relating them to the genes. For this purpose, we used a dataset of eye fundus photographs from 74 twin pairs, either monozygotic twins, who have the same genotype, or dizygotic twins, whose genes responsible for AMD are less likely to be identical. If we are able to differentiate monozygotic twins from dizygotic twins, based on a given visual pattern, then this pattern is likely to be controlled by genetic factors. The main visible consequence of AMD is the apparition of drusen between the retinal pigment epithelium and Bruch's membrane. We developed two automated drusen detectors based on the wavelet transform: a shape-based detector for hard drusen, and a texture- and color- based detector for soft drusen. Forty visual features were evaluated at the location of the automatically detected drusen. These features characterize the texture, the shape, the color, the spatial distribution, or the amount of drusen. A distance measure between twin pairs was defined for each visual feature; a smaller distance should be measured between monozygotic twins for visual features controlled by genetic factors. The predictions of several visual features (75.7% accuracy) are comparable or better than the predictions of human experts.

  7. Solomon Technique Versus Selective Coagulation for Twin-Twin Transfusion Syndrome.

    PubMed

    Slaghekke, Femke; Oepkes, Dick

    2016-06-01

    Monochorionic twin pregnancies can be complicated by twin-to-twin transfusion syndrome (TTTS). The best treatment option for TTTS is fetoscopic laser coagulation of the vascular anastomoses between donor and recipient. After laser therapy, up to 33% residual anastomoses were seen. These residual anastomoses can cause twin anemia polycythemia sequence (TAPS) and recurrent TTTS. In order to reduce the number of residual anastomoses and their complications, a new technique, the Solomon technique, where the whole vascular equator will be coagulated, was introduced. The Solomon technique showed a reduction of recurrent TTS compared to the selective technique. The incidence of recurrent TTTS after the Solomon technique ranged from 0% to 3.9% compared to 5.3-8.5% after the selective technique. The incidence of TAPS after the Solomon technique ranged from 0% to 2.9% compared to 4.2-15.6% after the selective technique. The Solomon technique may improve dual survival rates ranging from 64% to 85% compared to 46-76% for the selective technique. There was no difference reported in procedure-related complications such as intrauterine infection and preterm premature rupture of membranes. The Solomon technique significantly reduced the incidence of TAPS and recurrent TTTS and may improve survival and neonatal outcome, without identifiable adverse outcome or complications; therefore, the Solomon technique is recommended for the treatment of TTTS. PMID:27203607

  8. Genetic and Environmental Influences on Two Measures of Speed of Information Processing and Their Relation to Psychometric Intelligence: Evidence from the German Observational Study of Adult Twins.

    ERIC Educational Resources Information Center

    Neubauer, Alioscha C.; Spinath, Frank M.; Riemann, Rainer; Angleitner, Alois; Borkenau, Peter

    2000-01-01

    Administered 2 elementary cognitive task (ECT) tests and 2 psychometric intelligence tests to 169 monozygotic and 131 dizygotic pairs of twins in Germany. Reaction times correlated negatively with psychometric intelligence, and habitability estimates were substantial for both psychometric intelligence and reaction times on the ECTs. Multivariate…

  9. Twin Anemia Polycythemia Sequence: Current Views on Pathogenesis, Diagnostic Criteria, Perinatal Management, and Outcome.

    PubMed

    Tollenaar, Lisanne S A; Slaghekke, Femke; Middeldorp, Johanna M; Klumper, Frans J; Haak, Monique C; Oepkes, Dick; Lopriore, Enrico

    2016-06-01

    Monochorionic twins share a single placenta and are connected with each other through vascular anastomoses. Unbalanced inter-twin blood transfusion may lead to various complications, including twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS). TAPS was first described less than a decade ago, and the pathogenesis of TAPS results from slow blood transfusion from donor to recipient through a few minuscule vascular anastomoses. This gradually leads to anemia in the donor and polycythemia in the recipient, in the absence of twin oligo-polyhydramnios sequence (TOPS). TAPS may occur spontaneously in 3-5% of monochorionic twins or after laser surgery for TTTS. The prevalence of post-laser TAPS varies from 2% to 16% of TTTS cases, depending on the rate of residual anastomoses. Pre-natal diagnosis of TAPS is currently based on discordant measurements of the middle cerebral artery peak systolic velocity (MCA-PSV; >1.5 multiples of the median [MoM] in donors and 8 g/dL), and at least one of the following: reticulocyte count ratio >1.7 or minuscule placental anastomoses. Management includes expectant management, and intra-uterine blood transfusion (IUT) with or without partial exchange transfusion (PET) or fetoscopic laser surgery. Post-laser TAPS can be prevented by using the Solomon laser surgery technique. Short-term neonatal outcome ranges from isolated inter-twin Hb differences to severe neonatal morbidity and neonatal death. Long-term neonatal outcome in post-laser TAPS is comparable with long-term outcome after treated TTTS. This review summarizes the current knowledge after 10 years of research on the pathogenesis, diagnosis, management, and outcome in TAPS. PMID:27068715

  10. Twin Chorionicity and the Risk of Hypertensive Disorders: Gestational Hypertension and Pre-eclampsia.

    PubMed

    Bartnik, Pawel; Kosinska-Kaczynska, Katarzyna; Kacperczyk, Joanna; Ananicz, Wojciech; Sierocińska, Aleksandra; Wielgos, Miroslaw; Szymusik, Iwona

    2016-08-01

    Twin gestation is known to be a risk factor for hypertensive disorders of pregnancy. However, the relationship between hypertensive disorders (pre-eclampsia (PE) and gestational hypertension (GH)) and chorionicity of twin pregnancy is unclear, and published data is conflicting. We decided to analyze the relationship between placentation and prevalence of hypertensive disorders. It was a retrospective cohort study. 312 twin pregnancies delivered between 2009 and 2014 were analyzed, 79 of which were monochorionic and 233 dichorionic. The occurrence of PE and GH was established according to American College of Obstetricians and Gynecologists' (ACOG) guidelines. Hypertensive disorders were diagnosed significantly more often in dichorionic than in monochorionic twin pregnancies (19.7% vs. 8.9%; OR = 2.53 95% CI 1.04-6.45; p = .03). PE occurred more frequently in DCP (13.3% vs. 3.8%; OR = 3.88 95% CI 1.09-16.46; p = .02). There were no differences between those two groups in the prevalence of GH (6.4% vs. 5.1%; p = .79). The logistic regression model for the occurrence of PE included chorionicity, mother's age lower than 18 or higher than 40, pre-gestational obesity, in vitro fertilization, primiparity, gestational age at delivery, gestational diabetes, and active smoking. It showed that dichorionicity remained an independent risk factor for PE (adjusted OR = 4.97.0 95% CI 1.06-23.38; p = .04). Dichorionicity seems to be a risk factor for PE but not for GH development. PMID:27160962

  11. Neuropathologic assessment of dementia markers in identical and fraternal twins.

    PubMed

    Iacono, Diego; Volkman, Inga; Nennesmo, Inger; Pedersen, Nancy L; Fratiglioni, Laura; Johansson, Boo; Karlsson, David; Winblad, Bengt; Gatz, Margaret

    2014-07-01

    Twin studies are an incomparable source of investigation to shed light on genetic and non-genetic components of neurodegenerative diseases, as Alzheimer's disease (AD). Detailed clinicopathologic correlations using twin longitudinal data and post-mortem examinations are mostly missing. We describe clinical and pathologic findings of seven monozygotic (MZ) and dizygotic (DZ) twin pairs. Our findings show good agreement between clinical and pathologic diagnoses in the majority of the twin pairs, with greater neuropathologic concordance in MZ than DZ twins. Greater neuropathologic concordance was found for β-amyloid than tau pathology within the pairs. ApoE4 was associated with higher β-amyloid and earlier dementia onset, and importantly, higher frequency of other co-occurring brain pathologies, regardless of the zygosity. Dementia onset, dementia duration, difference between twins in age at dementia onset and at death, did not correlate with AD pathology. These clinicopathologic correlations of older identical and fraternal twins support the relevance of genetic factors in AD, but not their sufficiency to determine the pathology, and consequently the disease, even in monozygotic twins. It is the interaction among genetic and non-genetic risks which plays a major role in influencing, or probably determining, the degeneration of those brain circuits associated with pathology and cognitive deficits in AD. PMID:24450926

  12. The CODAtwins project: the cohort description of COllaborative project of Development of Anthropometrical measures in Twins to study macro-environmental variation in genetic and environmental effects on anthropometric traits

    PubMed Central

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo; Honda, Chika; Aaltonen, Sari; Yokoyama, Yoshie; Tarnoki, Adam D; Tarnoki, David L; Ning, Feng; Ji, Fuling; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Haworth, Claire MA; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Hong, Changhee; Chong, Youngsook; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth JF; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik KE; Pedersen, Nancy L; Dahl-Aslan, Anna K; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos CEM; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Rasmussen, Finn; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Boomsma, Dorret I; Hur, Yoon-Mi; Sørensen, Thorkild IA; Kaprio, Jaakko

    2015-01-01

    For over one hundred years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically 1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and 2) to study the effects of birth related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects including both monozygotic and dizygotic twins using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes. PMID:26014041

  13. The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits.

    PubMed

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo; Honda, Chika; Aaltonen, Sari; Yokoyama, Yoshie; Tarnoki, Adam D; Tarnoki, David L; Ning, Feng; Ji, Fuling; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Haworth, Claire M A; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Hong, Changhee; Chong, Youngsook; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth J F; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos C E M; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Rasmussen, Finn; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Boomsma, Dorret I; Hur, Yoon-Mi; Sørensen, Thorkild I A; Kaprio, Jaakko

    2015-08-01

    For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes. PMID:26014041

  14. Clinical outcomes after assisted reproductive technology in twin pregnancies: chorionicity-based comparison

    PubMed Central

    Sun, Luming; Zou, Gang; Wei, Xing; Chen, Yan; Zhang, Jun; Okun, Nanette; Duan, Tao

    2016-01-01

    The chorionicity–based evaluation of the perinatal risk in twin pregnancies after assisted reproductive technology (ART) is lacking. A retrospective review was performed of all twin pregnancies monitored prenatally and delivered at our hospital between 2010 and 2014. Chorionicity was diagnosed by ultrasound examination at first trimester and confirmed by postnatal pathology. Pregnancy and perinatal outcomes were prospectively recorded. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated in a logistic regression model. A total of 1153 twin pregnancies were analyzed. The occurrence of preterm premature rupture of membranes (PPROM) was 3 times as frequent in monochorionic diamniotic (MCDA) twin pregnancies after ART as in those spontaneous counterparts (aOR 3.0; 95%CI 1.1–3.2). The prevalence of intrahepatic cholestasis of pregnancies (ICP) was significantly higher in dichorionic diamniotic (DCDA) twin pregnancies following ART compared to spontaneous DCDA pregnancies (aOR 3.3; 95%CI 1.3–5.6). Perinatal outcomes did not differ between two conception methods, either in MCDA or DCDA twin pregnancies. Based on differentiation of chorionicity, ART is associated with the increased risk of PPROM in MCDA twin pregnancies and with a higher rate of ICP in DCDA twin gestations. ART does not increase adversity of perinatal outcomes in twin pregnancies. PMID:27243373

  15. Clinical outcomes after assisted reproductive technology in twin pregnancies: chorionicity-based comparison.

    PubMed

    Sun, Luming; Zou, Gang; Wei, Xing; Chen, Yan; Zhang, Jun; Okun, Nanette; Duan, Tao

    2016-01-01

    The chorionicity-based evaluation of the perinatal risk in twin pregnancies after assisted reproductive technology (ART) is lacking. A retrospective review was performed of all twin pregnancies monitored prenatally and delivered at our hospital between 2010 and 2014. Chorionicity was diagnosed by ultrasound examination at first trimester and confirmed by postnatal pathology. Pregnancy and perinatal outcomes were prospectively recorded. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated in a logistic regression model. A total of 1153 twin pregnancies were analyzed. The occurrence of preterm premature rupture of membranes (PPROM) was 3 times as frequent in monochorionic diamniotic (MCDA) twin pregnancies after ART as in those spontaneous counterparts (aOR 3.0; 95%CI 1.1-3.2). The prevalence of intrahepatic cholestasis of pregnancies (ICP) was significantly higher in dichorionic diamniotic (DCDA) twin pregnancies following ART compared to spontaneous DCDA pregnancies (aOR 3.3; 95%CI 1.3-5.6). Perinatal outcomes did not differ between two conception methods, either in MCDA or DCDA twin pregnancies. Based on differentiation of chorionicity, ART is associated with the increased risk of PPROM in MCDA twin pregnancies and with a higher rate of ICP in DCDA twin gestations. ART does not increase adversity of perinatal outcomes in twin pregnancies. PMID:27243373

  16. Non-random X chromosome inactivation in an affected twin in a monozygotic twin pair discordant for Wiedemann-Beckwith syndrome

    SciTech Connect

    Oestavik, R.E.; Eiklid, K.; Oerstavik, K.H.

    1995-03-27

    Wiedemann-Beckwith syndrome (WBS) is a syndrome including exomphalos, macroglossia, and generalized overgrowth. The locus has been assigned to 11p15, and genomic imprinting may play a part in the expression of one or more genes involved. Most cases are sporadic. An excess of female monozygotic twins discordant for WBS have been reported, and it has been proposed that this excess could be related to the process of X chromosome inactivation. We have therefore studied X chromosome inactivation in 13-year-old monozygotic twin girls who were discordant for WBS. In addition, both twins had Tourette syndrome. The twins were monochorionic and therefore the result of a late twinning process. This has also been the case in previously reported discordant twin pairs with information on placentation. X chromosome inactivation was determined in DNA from peripheral blood cells by PCR analysis at the androgen receptor locus. The affected twin had a completely skewed X inactivation, where the paternal allele was on the active X chromosome in all cells. The unaffected twin had a moderately skewed X inactivation in the same direction, whereas the mother had a random pattern. Further studies are necessary to establish a possible association between the expression of WBS and X chromosome inactivation. 18 refs., 2 figs., 1 tab.

  17. Genetic and experiential influences on behavior: Twins reunited at seventy-eight years

    PubMed Central

    Segal, Nancy L.; Cortez, Franchesca A.; Zettel-Watson, Laura; Cherry, Barbara J.; Mechanic, Mindy; Munson, Jaimee E.; Velázquez, Jaime M.A.; Reed, Brandon

    2015-01-01

    Twins living in different countries offer opportunities to explore associations between observed differences and experiential effects. This report compared the life histories, cognitive abilities, personality traits, psychomotor skills, medical characteristics, job satisfaction, social support and social relations of dizygotic (DZ) female twins reunited at 78, the world's longest separated set. The twins’ advanced age also enabled a study of how co-twin differences in aging may be associated with current behavioral and social differences. Consistent with previous studies, these dizygotic reared apart (DZA) twins showed discordance across some, but not all, traits. Their different rearing situations and life histories may explain current differences in their responses to meeting their twin. This case highlights the importance of both genetic and rearing factors on behavior, but does not allow firm conclusions regarding the extent to which these sources explain individual developmental differences. However, such data contribute to the growing number of cross-culturally separated twins, generating novel hypotheses that may be assessed using larger samples. PMID:26366029

  18. Face processing among twins with and without autism: social correlates and twin concordance.

    PubMed

    Neuhaus, Emily; Kresse, Anna; Faja, Susan; Bernier, Raphael A; Webb, Sara Jane

    2016-01-01

    Autism spectrum disorder (ASD) has a strong heritable basis, as evidenced by twin concordance rates. Within ASD, symptom domains may arise via independent genetic contributions, with varying heritabilities and genetic mechanisms. In this article, we explore social functioning in the form of (i) electrophysiological and behavioral measures of face processing (P1 and N170) and (ii) social behavior among child and adolescent twins with (N = 52) and without ASD (N = 66). Twins without ASD had better holistic face processing and face memory, faster P1 responses and greater sensitivity to the effects of facial inversion on P1. In contrast, N170 responses to faces were similar across diagnosis, with more negative amplitudes for faces vs non-face images. Across the sample, stronger social skills and fewer social difficulties were associated with faster P1 and N170 responses to upright faces, and better face memory. Twins were highly correlated within pairs across most measures, but correlations were significantly stronger for monozygotic vs dizygotic pairs on N170 latency and social problems. We suggest common developmental influences across twins for face processing and social behavior, but highlight (i) neural speed of face processing and (ii) social difficulties as important avenues in the search for genetic underpinnings in ASD. PMID:26137974

  19. Genetic determinants of bone mass in adults. A twin study.

    PubMed Central

    Pocock, N A; Eisman, J A; Hopper, J L; Yeates, M G; Sambrook, P N; Eberl, S

    1987-01-01

    The relative importance of genetic factors in determining bone mass in different parts of the skeleton is poorly understood. Lumbar spine and proximal femur bone mineral density and forearm bone mineral content were measured by photon absorptiometry in 38 monozygotic and 27 dizygotic twin pairs. Bone mineral density was significantly more highly correlated in monozygotic than in dizygotic twins for the spine and proximal femur and in the forearm of premenopausal twin pairs, which is consistent with significant genetic contributions to bone mass at all these sites. The lesser genetic contribution to proximal femur and distal forearm bone mass compared with the spine suggests that environmental factors are of greater importance in the aetiology of osteopenia of the hip and wrist. This is the first demonstration of a genetic contribution to bone mass of the spine and proximal femur in adults and confirms similar findings of the forearm. Furthermore, bivariate analysis suggested that a single gene or set of genes determines bone mass at all sites. PMID:3624485

  20. Healthy co-twins of patients with affective disorders show reduced risk-related activation of the insula during a monetary gambling task

    PubMed Central

    Macoveanu, Julian; Miskowiak, Kamilla; Kessing, Lars Vedel; Vinberg, Maj; Siebner, Hartwig Roman

    2016-01-01

    Background Healthy first-degree relatives of patients with affective disorders are at increased risk for affective disorders and express discrete structural and functional abnormalities in the brain reward system. However, value-based decision making is not well understood in these at-risk individuals. Methods We investigated healthy monozygotic and dizygotic twins with or without a co-twin history of affective disorders (high-risk and low-risk groups, respectively) using functional MRI during a gambling task. We assessed group differences in activity related to gambling risk over the entire brain. Results We included 30 monozygotic and 37 dizygotic twins in our analysis. Neural activity in the anterior insula and ventral striatum increased linearly with the amount of gambling risk in the entire cohort. Individual neuroticism scores were positively correlated with the neural response in the ventral striatum to increasing gambling risk and negatively correlated with individual risk-taking behaviour. Compared with low-risk twins, the high-risk twins showed a bilateral reduction of risk-related activity in the middle insula extending into the temporal cortex with increasing gambling risk. Post hoc analyses revealed that this effect was strongest in dizygotic twins. Limitations The relatively old average age of the mono- and dizygotic twin cohort (49.2 yr) may indicate an increased resilience to affective disorders. The size of the monozygotic high-risk group was relatively small (n = 13). Conclusion The reduced processing of risk magnitude in the middle insula may indicate a deficient integration of exteroceptive information related to risk-related cues with interoceptive states in individuals at familial risk for affective disorders. Impaired risk processing might contribute to increased vulnerability to affective disorders. PMID:26395812

  1. Associations Between Sibling Relationship Quality and Friendship Quality in Early Adolescence: Looking at the Case of Twins.

    PubMed

    Bekkhus, Mona; Brendgen, Mara; Czajkowski, Nikolai O; Vitaro, Frank; Dionne, Ginette; Boivin, Michel

    2016-04-01

    Bidirectional pathways between twin relationship quality and friendship quality were investigated in a large longitudinal twin cohort. We examined negative and positive relationship features in 313 monozygotic (MZ) twins and 238 same-sex dizygotic (DZ) twins from ages 13 to 14 years, using latent structural modeling. Results showed stronger stability of the twin relationship quality compared to friendship quality. Positive features in the sibling relationship were associated with increased positive features in the relationship with the best friend a year later. In contrast, no significant association between negative sibling relationship features and change in negative friendship quality features was found. These findings speak to the important role of the sibling relationship in the development of good quality friendship relations in twins. PMID:26952576

  2. Isolated Single Umbilical Artery in Twin Pregnancies and its Adverse Pregnancy Outcomes - A Case Report and Review of Literature

    PubMed Central

    Raiz, Iqbal

    2015-01-01

    Single umbilical artery is the most common congenital abnormality of the umbilical cord and is seen in 4-11% of twin pregnancies. It is usually associated with intrauterine growth retardation, preterm labour, small-for-dates and other structural anomalies. There is no significant difference in the incidence between monochorionic and dichorionic twins. The left artery is usually absent more commonly than the right. The female co-twin was predominantly more affected than their male counterparts. Single umbilical artery is found twice more common in white women than in Afro-Asians and Americans. The hemodynamic disturbances occur early in the embryonic development, influence greatly in the development of single umbilical artery. Genetic and environmental factors also play a major role in the development of this anomaly. The pregnancies with single umbilical artery were classified as high risk group, because the overall perinatal mortality rate was estimated to be as high as 20%. There is a significant increase in the occurrence of single umbilical artery in pregnancies due to artificial reproductive technologies, as well as in spontaneous miscarriages. Prenatal ultrasonography is the principal diagnostic technique employed to identify single umbilical artery during 3rd trimester of pregnancy. The present case, reports the presence of a single umbilical artery in a monozygotic, monochorionic twin pregnancy, which is acardiac-acephalic fetus, small for dates, female sex, associated with other major structural anomalies, and was still born. Authors analyse its incidence, clinical presentations and pregnancy outcome and also review the pertinent literature. PMID:25737967

  3. Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project.

    PubMed

    Yokoyama, Yoshie; Jelenkovic, Aline; Sund, Reijo; Sung, Joohon; Hopper, John L; Ooki, Syuichi; Heikkilä, Kauko; Aaltonen, Sari; Tarnoki, Adam D; Tarnoki, David L; Willemsen, Gonneke; Bartels, Meike; van Beijsterveldt, Toos C E M; Saudino, Kimberly J; Cutler, Tessa L; Nelson, Tracy L; Whitfield, Keith E; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; He, Mingguang; Ding, Xiaohu; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Jeong, Hoe-Uk; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Burt, S Alexandra; Klump, Kelly L; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Harris, Jennifer R; Brandt, Ingunn; Nilsen, Thomas Sevenius; Craig, Jeffrey M; Saffery, Richard; Ji, Fuling; Ning, Feng; Pang, Zengchang; Dubois, Lise; Boivin, Michel; Brendgen, Mara; Dionne, Ginette; Vitaro, Frank; Martin, Nicholas G; Medland, Sarah E; Montgomery, Grant W; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Tynelius, Per; Haworth, Claire M A; Plomin, Robert; Rebato, Esther; Rose, Richard J; Goldberg, Jack H; Rasmussen, Finn; Hur, Yoon-Mi; Sørensen, Thorkild I A; Boomsma, Dorret I; Kaprio, Jaakko; Silventoinen, Karri

    2016-04-01

    We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI. PMID:26996222

  4. Monozygotic twins with Crohn's disease and ulcerative colitis: a unique case report

    PubMed Central

    Breslin, N; Todd, A; Kilgallen, C; O'Morain, C

    1997-01-01

    Background—A large number of monozygotic and dizygotic twin pairs with inflammatory bowel disease have been reported. To date no twin pair has developed phenotypically discordant inflammatory bowel disease. This case report is the first documented occurrence of discordant inflammatory bowel disease occurring in monozygotic twins. 
Case report—Twenty two year old identical male twins presented within three months of each other with inflammatory bowel disease that proved to be discordant in overall disease type, disease distribution, clinical course, and histopathological findings. Twin 1 developed a severe pancolitis necessitating total colectomy while twin 2 developed a predominantly distal patchy colitis with frequent granulomas, controlled by aminosalicylates. Twin 1 was antineutrophil cytoplasmic antibody (ANCA) negative at the time of testing while twin 2 (Crohn's disease) was ANCA positive. Significantly, the twins possessed the HLA type DR3-DR52-DQ2 previously associated with extensive colitis. 
Conclusion—This case report confirms the important role played by genetic factors in the development of inflammatory bowel disease. It also highlights the crucial role of undetermined environmental agents in dictating disease expression and phenotype. 

 Keywords: monozygotic twins; ulcerative colitis; Crohn's disease; inflammatory bowel disease PMID:9391259

  5. Twin Gestation in a Septate Bicornuate Uterus

    PubMed Central

    2012-01-01

    Bicornuate and septate uteri are among the commonest Mullerian anomalies. They are sporadic and fairly distinguished, but hybrid deformities can occur. This combination creates aetiological and clinical difficulties. The alternative theory of concurrent fusion and septal resorption of the Mullerian duct is seen as the basis of the altered foetal embryology, while the favourable outlook of a bicornuate uterus may be offset by the suboptimal implantation across the avascular septum. Obstetric care is based on empirical interventions deduced from case series, with varied and inconsistent outcomes. We present a 32-year-old primipara with a dizygotic twin gestation in separate compartments of a septate bicornuate uterus. She had an elective bilateral caesarean delivery at term with an accidental septal resection for morbidly adherent placenta. Although a summation of obstetric risks is a possibility, an excellent outcome was observed. PMID:23304585

  6. [PROBLEMS OF NEWBORN NEONATAL ADAPTATION FROM A TWINS].

    PubMed

    Nikitina, I; Boykо, V; Babar, T; Kalashnik, N; Yezhova, A

    2016-04-01

    The clinical analysis of multiple pregnancies. The features of neonatal adaptation process in 96 twins, depending on the type of zygosity. It is proved that the adaptation of the newborn with multiple pregnancy depends on the type of placentation. It is found that monozygotic twins is a risk factor syndromes disadaptation. Children from monozygotic twins compared with dizygotic twins have a higher frequency of the syndrome of respiratory disorders, and more prone to jaundice, hemorrhagic syndrome, violation gemolikvorodinamics II and III degrees. The physical development of the twins also determined by the type zygosity. In the group of monozygotic twins are more common heavier versions of intrauterine growth retardation - hypoplastic and dysplastic. The high frequency of asphyxia on the background of immaturity that leads to the development disadaptation syndromes in these children, the most common of which are hypoxic-ischemic CNS disorders, thermoregulation, jaundice and gastrointestinal reactions. Detection disorders of blood coagulation and glucose metabolism certainly play a negative role in the development of adaptation of these newborns. zygosity type must be determined at the time of pregnancy to produce medical tactics and prognosis. PMID:27249428

  7. The Host Genotype and Environment Affect Strain Types of Bifidobacterium longum subsp. longum Inhabiting the Intestinal Tracts of Twins

    PubMed Central

    Zhang, Min; Hang, Xiaomin; Tan, Jing

    2015-01-01

    To investigate the influences of host genotype and environment on Bifidobacterium longum subsp. longum inhabiting human intestines at the strain level, six pairs of twins, divided into two groups (children and adults), were recruited. Each group consisted of two monozygotic (MZ) twin pairs and one dizygotic (DZ) twin pair. Child twins had been living together from birth, while adult twins had been living separately for 5 to 10 years. A total of 345 B. longum subsp. longum isolates obtained from 60 fecal samples from these twins were analyzed by multilocus sequence typing (MLST), and 35 sequence types (STs) were finally acquired. Comparison of strains within and between the twin pairs showed that no strains with identical STs were observed between unrelated individuals or within adult DZ twin pairs. Eight STs were found to be monophyletic, existing within MZ twins and child DZ twins. The similarity of strain types within child cotwins was significantly higher than that within adult cotwins, which indicated that environment was one of the important determinants in B. longum subsp. longum strain types inhabiting human intestines. However, although these differences between MZ and DZ twins were observed, it is still difficult to reach an exact conclusion about the impact of host genotype. This is mainly because of the limited number of subjects tested in the present study and the lack of strain types tracing in the same twin pairs from birth until adulthood. PMID:25956768

  8. Familial factors in early deaths: twins followed 30 years to ages 51-61 in 1978.

    PubMed

    Hrubec, Z; Neel, J V

    1981-01-01

    Subjects in the National Academy of Sciences-National Research Council Twin Registry of 31,848 male twin veterans were followed for mortality from 1 January 1946, or from the date of entry into military service if that was later, to 31 December 1978. During this time 3,573 deaths occurred among them, 837 due to trauma and 2,712 due to disease. Mortality from all causes for the entire follow-up period was 10.2% among 11,350 monozygotic (MZ) twins and 11.4% among 14,450 dizygotic (DZ) twins. Mortality of veterans is known to be favorable compared to U.S. males. Among U.S. males of the same ages as the two respective twin zygosity groups, a mortality of 13.9% would have been expected during this time period. Observed mortality from trauma was 2.3% for MZ twins and 2.5% for DZ twins, with 3.0% expected in either group. Observed mortality from all disease was 7.9% for MZ twins and 8.8% for DZ twins, with 10.9% expected in either group. For total mortality, the case twin concordance rates, based on individual deaths, were 28.2% among MZ twins and 17.7% among DZ twins. For trauma, respectively by zygosity, these concordance rates were 6.9% and 3.9%. In this sample, familial factors appear to be of little consequence in trauma deaths. For all disease the concordance rates were 30.1% and 17.4%. Estimating heritability of liability to death from disease, as proposed by Edwards (1969), provides values of h2 = r = 0.51 for MZ twins, h2 = 2r = 0.48 for DZ twins, and h2 = 2(rMZ-rDZ) = 0.54 using data for the two zygosity groups combined. PMID:10819020

  9. Examining Associations Among ADHD, Homework Behavior, and Reading Comprehension: A Twin Study.

    PubMed

    Little, Callie W; Hart, Sara A; Schatschneider, Christopher; Taylor, Jeanette

    2016-07-01

    Previous literature has indicated an important association between reading comprehension and both attention-deficit/hyperactivity disorder (ADHD) and homework habits. This investigation sought to extend previous knowledge by providing information about how ADHD and homework behavior (i.e., completing homework regularly) may jointly influence reading comprehension. Using a genetically sensitive design, this study examined the genetic and environmental influences on and between ADHD, homework behavior and reading comprehension. Participants for this study included 691 twin pairs (351 monozygotic, 340 same-sex dizygotic) from the Florida Twin Project on Behavior and Environment (FTP-BE) and 2647 twin pairs (865 monozygotic, 1782 dizygotic) from the larger Florida Twin Project on Reading (FTP-R) in Grades 3 through 7. Three separate models, each representing a different definition of ADHD (full ADHD, inattention only, and hyperactivity/impulsivity only), showed similar patterns of results; therefore, results of the full ADHD model are discussed. Overlapping genetic influences were found between ADHD, homework behavior, and reading comprehension, but no shared environmental influences among all three. However, shared environmental influences overlapped between homework behavior and reading comprehension. Although the sources of this environmental overlap are unknown, these results have implications for improving homework practices and their subsequent influence on literacy skills through homework environments. PMID:25349092

  10. Evidence for No Significant Impact of Müllerian Anomalies on Reproductive Outcomes of Twin Pregnancy in Korean Women.

    PubMed

    Shim, Sohyun; Hur, Yoon-Mi; Kim, Da Hee; Seong, Seok Ju; Kim, Mi-La; Shin, Joong Sik

    2016-04-01

    The present article aimed to evaluate the impact of congenital Müllerian anomalies (MA) on twin pregnancy after 24 gestational weeks in Korean women. All records of twin pregnancies in a large maternity hospital in Korea between January 2005 and July 2013 were analyzed. Patients with monochorionic monoamniotic (MCMA) twins, non-Korean patients, patients with twins delivered prior to 24 gestational weeks, and patients with miscarriage of one fetus or intrauterine fetal death (IUFD) before 24 gestational weeks were excluded from data analysis. In total, 1,422 women with twin pregnancy were eligible for data analysis, including 17 (1.2%) who had a known congenital MA (septate uterus, bicornuate uterus, arcuate uterus, and unicornuate uterus). Except for the mode of conception, baseline demographics were similar between women with MA and those without MA. No significant differences were found in pregnancy outcomes of gestational age at delivery (p = .86), birth weight of smaller and larger twins (p = .54 and p = .65), and number of twins with birth weight <5th percentile for gestational age (p = .43).The rates of obstetrical complications such as pre-eclampsia, gestational diabetes mellitus (GDM), placenta previa, cerclage, IUFD, and postpartum hemorrhage were not significantly different between the two groups either. We concluded that the presence of congenital MA may not increase obstetrical risks in outcomes of pregnancy of twins delivered after 24 gestational weeks. PMID:26880019

  11. The Influence of Chorion Type on Health Measures at Birth and Dental Development in Australian and Dutch Twins: A Comparative Study.

    PubMed

    Mihailidis, Suzanna; Bockmann, Michelle; McConnell, Elise; Hughes, Toby; van Beijsterveldt, Toos C E M; Boomsma, Dorret I; McMaster, Minni; Townsend, Grant

    2015-08-01

    Chorion type may significantly influence the prenatal environment of twins. This study explored the associations between chorion type and gestational age, birth weight, birth length, and the timing of emergence of the first primary tooth in two populations of twins, Australian and Dutch. Additionally, we investigated the relationship between chorion type and birth weight discordance (BWD) in order to determine whether a significant relationship existed between discordance in birth weight and discordance in the timing of emergence of the first primary tooth. The two study samples consisted of 409 Australian twin pairs and 301 Dutch twin pairs, all of European ancestry. Data were collected through a combination of questionnaires and recording charts administered to the parents and through linkage with biological databases. In the Australian sample, monozygotic monochorionic (MZMC) twins experienced the shortest mean gestation time (35 weeks), the lowest mean birth length (46 cm) and the lowest mean birth weight (2.3 kg) compared with other twin groups. For the same variables in the Dutch sample, these trends with MZMC twinning were not observed. Chorion type did not significantly affect the mean timing of emergence of the first primary tooth in either sample. Monochorionicity was found to be significantly associated with BWD in both samples, but there was a significant association between BWD in MZMC twin pairs and timing of emergence of the first primary tooth only in the Australian sample. Results from this study support previous findings that the timing of emergence of the first primary tooth is influenced strongly by genetic factors and is well protected from environmental disturbances. PMID:26227835

  12. A test of the equal-environment assumption in twin studies of psychiatric illness.

    PubMed

    Kendler, K S; Neale, M C; Kessler, R C; Heath, A C; Eaves, L J

    1993-01-01

    The traditional twin method is predicated on the equal-environment assumption (EEA)--that monozygotic (MZ) and dizygotic (DZ) twins are equally correlated in their exposure to environmental events of etiologic importance for the trait under study. In 1968, Scarr proposed a test of the EEA which examines the impact of phenotypic similarity in twins of perceived versus true zygosity. We apply this test for the EEA to five common psychiatric disorders (major depression, generalized anxiety disorder, phobia, bulimia, and alcoholism), as assessed by personal interview, in 1030 female-female twin pairs from the Virginia Twin Registry with known zygosity. We use a newly developed model-fitting approach which treats perceived zygosity as a form of specified familial environment. In 158 of the 1030 pairs (15.3%), one or both twins disagreed with the project-assigned zygosity. Model fitting provided no evidence for a significant influence of perceived zygosity on twin resemblance for any of the five disorders. Although limited in power, these results support the validity of the EEA in twin studies of psychiatric disorders. PMID:8476388

  13. Twinning in the offspring of parents with chronic radiation exposure from nuclear testing in Kazakhstan.

    PubMed

    Mudie, Nadejda Y; Swerdlow, Anthony J; Gusev, Boris I; Schoemaker, Minouk J; Pivina, Ludmila M; Chsherbakova, Svetlana; Mansarina, Almagul; Bauer, Susanne; Jakovlev, Yuri; Apsalikov, Kazbek N

    2010-06-01

    The population of the Semipalatinsk region of Kazakhstan was chronically exposed to radioactive fallout from above-ground nuclear tests conducted during 1949-1956 by the Soviet Union. We investigated the effect of radiation exposure and other factors on risks of twinning overall and of same- and different-sex twinning and hence estimated dizygotic and monozygotic twinning rates in 11,605 deliveries around Semipalatinsk, 141 of which were twin, to 3992 mothers exposed to fallout during 1949-1956. Overall, the same-sex twinning rate was 7.85 [95% confidence interval (CI): 6.24, 9.47] per 1000 and the opposite-sex twinning rate was 4.45 (95% CI: 3.23, 5.67). Twinning rates did not differ significantly between radiation exposure categories, parental age at main radiation exposure, or year of birth. Different-sex, but not same-sex, twinning increased with maternal age (P(trend) = 0.04) but not with other demographic factors and was increased soon after radiation exposure [OR = 4.08 (95% CI: 1.11, 15.07)] for births occurring within 5 years compared with more than 20 years after exposure; this effect was similar in villages with low and high radiation exposure, however, so interpretation is uncertain. PMID:20518662

  14. Zygosity differences in height and body mass index of twins from infancy to old age: A study of the CODATwins project

    PubMed Central

    Jelenkovic, Aline; Yokoyama, Yoshie; Sund, Reijo; Honda, Chika; Bogl, Leonie H; Aaltonen, Sari; Ji, Fuling; Ning, Feng; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Tarnoki, Adam D; Tarnoki, David L; Haworth, Claire MA; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Rijsdijk, Fruhling; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Kim, Bia; Chong, Youngsook; Hong, Changhee; Shin, Hyun Jung; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth JF; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik KE; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos CEM; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Rasmussen, Finn; Hur, Yoon-Mi; Boomsma, Dorret I; Sørensen, Thorkild IA; Kaprio, Jaakko; Silventoinen, Karri

    2015-01-01

    A trend towards greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in means and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the CODATwins project and included 842,951 height and BMI measurements from age 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Likewise, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast the variance of BMI was significantly higher in DZ than in MZ twins particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes. PMID:26337138

  15. A study of genetic and environmental contributions to structural brain changes over time in twins concordant and discordant for bipolar disorder.

    PubMed

    Bootsman, F; Brouwer, R M; Schnack, H G; Kemner, S M; Hillegers, M H J; Sarkisyan, G; van der Schot, A C; Vonk, R; Hulshoff Pol, H E; Nolen, W A; Kahn, R S; van Haren, N E M

    2016-08-01

    This is the first longitudinal twin study examining genetic and environmental contributions to the association between liability to bipolar disorder (BD) and changes over time in global brain volumes, and global and regional measures of cortical surface area, cortical thickness and cortical volume. A total of 50 twins from pairs discordant or concordant for BD (monozygotic: 8 discordant and 3 concordant pairs, and 1 patient and 3 co-twins from incomplete pairs; dizygotic: 6 discordant and 2 concordant pairs, and 1 patient and 7 co-twins from incomplete pairs) underwent magnetic resonance imaging twice. In addition, 57 twins from healthy twin pairs (15 monozygotic and 10 dizygotic pairs, and 4 monozygotic and 3 dizygotic subjects from incomplete pairs) were also scanned twice. Mean follow-up duration for all twins was 7.5 years (standard deviation: 1.5 years). Data were analyzed using structural equation modeling software OpenMx. The liability to BD was not associated with global or regional structural brain changes over time. Although we observed a subtle increase in cerebral white matter in BD patients, this effect disappeared after correction for multiple comparisons. Heritability of brain changes over time was generally low to moderate. Structural brain changes appear to follow similar trajectories in BD patients and healthy controls. Existing brain abnormalities in BD do not appear to progressively change over time, but this requires additional confirmation. Further study with large cohorts is recommended to assess genetic and environmental influences on structural brain abnormalities in BD, while taking into account the influence of lithium on the brain. PMID:27218817

  16. Twin supergravities

    NASA Astrophysics Data System (ADS)

    Roest, Diederik; Samtleben, Henning

    2009-08-01

    We study the phenomenon that pairs of supergravities can have identical bosonic field content but different fermionic extensions. Such twin theories are classified and shown to originate as truncations of a common theory with more supersymmetry. Moreover, we discuss the possible gaugings and scalar potentials of twin theories. This allows us to pinpoint to which extent these structures are determined by the purely bosonic structure of the underlying Kac-Moody algebras and where supersymmetry comes to play its role. As an example, we analyse the gaugings of the six-dimensional {\\cal N}=(0,1) and {\\cal N}=(2,1) theories with an identical bosonic sector and explicitly work out their scalar potentials. The discrepancy between the potentials finds a natural explanation within maximal supergravity, in which both theories may be embedded.

  17. Change of maternal thyroid function in twin-twin transfusion syndrome.

    PubMed

    Hanaoka, Masachi; Arata, Naoko; Sago, Haruhiko

    2015-01-01

    Human chorionic gonadotropin (hCG) has weak thyroid-stimulating activity because of its homology with thyroid stimulating hormone (TSH). In twin-twin transfusion syndrome (TTTS), which is a severe complication of monochorionic twin pregnancies, a close association between maternal serum hCG concentration and TTTS has been reported. And, TTTS can be treated by fetoscopic laser coagulation of the communicating vessels. To clarify the relationship between maternal serum hCG and maternal thyroid function in TTTS, the present study investigated the change in thyroid hormone and hCG levels after laser therapy. The protocol included collection of serial maternal blood samples in TTTS before laser therapy, and at two and four weeks after laser therapy. For 131 cases of TTTS, the following parameters were determined at each point: hCG, TSH, free triiodothyronine (fT3), and free thyroxine (fT4). The multiple of the median (MoM) of pre-operative hCG concentration in TTTS was 5.39 MoM (interquartile range, 2.83 - 8.64). There was a moderate positive correlation between hCG and fT3 in TTTS pre-operatively (R = 0.22, P = 0.030). fT4 was also positively correlated with hCG (R = 0.33, P < 0.001). Some cases showed very high concentration in fT3. When laser therapy for TTTS was effective, the hCG concentration significantly decreased, and fT3 and fT4 decreased progressively in concert with the decrease in hCG. The relationship between hCG and thyroid function in TTTS supports the finding of TTTS as a novel etiology of hCG-mediated hyperthyroidism during pregnancy. PMID:26194271

  18. Parental style. Mothers' and fathers' and perceptions of their relations with twin children.

    PubMed

    Cohen, D J; Dibble, E; Grawe, J M

    1977-04-01

    Mothers and fathers rated their interaction with twin children on the Parent's Report (PR) questionnaire containing two scales-how the parent actually relates and how the ideal parent would relate. Mothers and fathers differed in parental style. Mothers perceived themselves as being profoundly more child-centered; fathers perceived themselves as using more control through arousal of guilt and anxiety. Parents asserted more control through temper and detachment with same-sex children. Boys and girls and monozygotic (MZ) and dizygotic (DZ) twins did not receive distinctly different parenting. Parents described MZ children as much more similar than DZ children but acted similarly with children in both types of twinships. Parental knowledge of zygosity did not affect the way the parents treated children. These findings suggest the relative importance of genetic contributions to behavioral similarity in MZ twins. PMID:557964

  19. The Role of Nature and Nurture for Individual Differences in Primary Emotional Systems: Evidence from a Twin Study

    PubMed Central

    Reuter, Martin; Spinath, Frank M.; Davis, Ken; Panksepp, Jaak

    2016-01-01

    The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS) by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings), moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33%) and highest for the PLAY system (69%). Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research. PMID:26999649

  20. The Role of Nature and Nurture for Individual Differences in Primary Emotional Systems: Evidence from a Twin Study.

    PubMed

    Montag, Christian; Hahn, Elisabeth; Reuter, Martin; Spinath, Frank M; Davis, Ken; Panksepp, Jaak

    2016-01-01

    The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS) by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings), moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33%) and highest for the PLAY system (69%). Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research. PMID:26999649

  1. Twin-reversed arterial perfusion sequence associated with decreased fetal cerebral vascular impedance

    PubMed Central

    Peyvandi, S.; Feldstein, V. A.; Hirose, S.; Rand, L.; Brook, M. M.; Moon-Grady, A. J.

    2015-01-01

    Objectives Twin-reversed arterial perfusion (TRAP) sequence affects 1% of monochorionic twin pregnancies and is caused by abnormal vascular connections between a pump twin and an acardiac mass. The effects of abnormal vascular connections on cerebral vasculature in the pump twin are unknown. We hypothesize that abnormal cerebral vascular impedance, as assessed by the pulsatility index (PI), is present in pump twins and that fetal intervention alters cerebral impedance. Methods Fetal echocardiograms performed between 2010 and 2013 in pregnancies diagnosed with TRAP (n = 19), recorded at presentation, and uncomplicated monochorionic twin pregnancies (controls, n = 18; 36 fetuses) were analyzed. In all subjects, the middle cerebral artery (MCA)-PI, combined cardiac output (CCO) and cardiothoracic ratio were calculated, and the values for cases and controls were compared. Results The mean gestational age at the time of echocardiography was 20 weeks in both groups. MCA-PI was lower in TRAP cases than in controls (1.55 (95%CI, 1.47–1.64) vs 1.74 (95% CI, 1.65–1.82), respectively; P = 0.004). CCO in TRAP cases was mildly elevated for gestational age (199.7 (95% CI, 138.4–261.1) mL/min) compared with that of controls (131.4 (95% CI, 102.2–160.7) mL/min). In six TRAP cases with a second echocardiogram available, the mean MCA-PI increased after intervention, from 1.5 (95%CI, 1.3–1.7) to 1.8 (95% CI, 1.4–2.2). Conclusions TRAP pump twins have lower cerebral vascular impedance than do controls, suggestive of a brain-sparing effect. MCA-PI appeared to increase in a small group of pump twins after intervention. These findings suggest a fetal cerebral autoregulatory response to a high cardiac output state that begins to change after fetal intervention. The long-termimplications for neurodevelopmental outcome warrant further study. PMID:25157457

  2. Synesthesia in twins: incomplete concordance in monozygotes suggests extragenic factors.

    PubMed

    Bosley, Hannah G; Eagleman, David M

    2015-06-01

    Colored-sequence synesthesia (CSS) is a neurological condition in which sequential stimuli such as letters, numbers, or days of the week trigger simultaneous, involuntary color perception. Although the condition appears to run in families and several studies have sought a genetic link, the genetic contribution to synesthesia remains unclear. We conducted the first comparative twin study of CSS and found that CSS has a pairwise concordance of 73.9% in monozygotic twins, and a pairwise concordance of 36.4% in dizygotic twins. In line with previous studies, our results suggest a heritable element of synesthesia. However, consonant with the findings of previous single-pair case studies, our large sample size verifies that synesthesia is not completely conferred by genetics; if it were, monozygotic twins should have 100% concordance. These findings implicate a genetic mechanism of CSS that may work differently than previously thought: collectively, our data suggest that synesthesia is a heritable condition with incomplete penetrance that is substantially influenced by epigenetic and environmental factors. PMID:25704836

  3. Ecosensitivity and genetic polymorphism of somatic traits in the perinatal development of twins.

    PubMed

    Waszak, Małgorzata; Cieślik, Krystyna; Skrzypczak-Zielińska, Marzena; Szalata, Marlena; Wielgus, Karolina; Kempiak, Joanna; Bręborowicz, Grzegorz; Słomski, Ryszard

    2016-04-01

    In view of criticism regarding the usefulness of heritability coefficients, the aim of this study was to analyze separately the information on genetic and environmental variability. Such an approach, based on the normalization of trait's variability for its value, is determined by the coefficients of genetic polymorphism (Pg) and ecosensitivity (De). The studied material included 1263 twin pairs of both sexes (among them 424 pairs of monozygotic twins and 839 pairs of dizygotic twins) born between the 22nd and 41st week of gestation. Variability of six somatic traits was analyzed. The zygosity of same-sex twins was determined based on the polymorphism of DNA from lymphocytes of the umbilical cord blood, obtained at birth. The coefficients of genetic polymorphism and ecosensitivity for analyzed traits of male and female twins born at various months of gestation were calculated. Our study revealed that a contribution of the genetic component predominated over that of the environmental component in determining the phenotypic variability of somatic traits of newborns from twin pregnancies. The genetically determined phenotypic variability in male twins was greater than in the females. The genetic polymorphism and ecosensitivity of somatic traits were relatively stable during the period of fetal ontogeny analyzed in this study. Only in the case of body weight, a slight increase in the genetic contribution of polygenes to the phenotypic variance could be observed with gestational age, along with a slight decrease in the influence of environmental factors. PMID:26619791

  4. The Nature and Nurture of Melody: A Twin Study of Musical Pitch and Rhythm Perception.

    PubMed

    Seesjärvi, Erik; Särkämö, Teppo; Vuoksimaa, Eero; Tervaniemi, Mari; Peretz, Isabelle; Kaprio, Jaakko

    2016-07-01

    Both genetic and environmental factors are known to play a role in our ability to perceive music, but the degree to which they influence different aspects of music cognition is still unclear. We investigated the relative contribution of genetic and environmental effects on melody perception in 384 young adult twins [69 full monozygotic (MZ) twin pairs, 44 full dizygotic (DZ) twin pairs, 70 MZ twins without a co-twin, and 88 DZ twins without a co-twin]. The participants performed three online music tests requiring the detection of pitch changes in a two-melody comparison task (Scale) and key and rhythm incongruities in single-melody perception tasks (Out-of-key, Off-beat). The results showed predominantly additive genetic effects in the Scale task (58 %, 95 % CI 42-70 %), shared environmental effects in the Out-of-key task (61 %, 49-70 %), and non-shared environmental effects in the Off-beat task (82 %, 61-100 %). This highly different pattern of effects suggests that the contribution of genetic and environmental factors on music perception depends on the degree to which it calls for acquired knowledge of musical tonal and metric structures. PMID:26650514

  5. Twinning of dodecanedicarboxylic acid

    NASA Technical Reports Server (NTRS)

    Sen, R.; Wilcox, W. R.

    1986-01-01

    Twinning of 1,10-dodecanedicarboxyl acid (DDA) was observed in 0.1 mm thick films with a polarizing microscope. Twins originated from polycrystalline regions which tended to nucleate on twin faces, and terminated by intersection gone another. Twinning increased dramatically with addition of organic compounds with a similar molecular size and shape. Increasing the freezing rate, increasing the temperature gradient, and addition of silica particles increased twinning. It is proposed that twins nucleate with polycrystals and sometimes anneal out before they become observable. The impurities may enhance twinning either by lowering the twin energy or by adsorbing on growing faces.

  6. Epidemiology of twinning in the National Birth Defects Prevention Study, 1997–2007

    PubMed Central

    Dawson, April L.; Tinker, Sarah C.; Jamieson, Denise J.; Hobbs, Charlotte A.; Rasmussen, Sonja A.; Reefhuis, Jennita

    2015-01-01

    Background Our objective was to evaluate associations between twinning and maternal demographic factors and periconceptional exposures among infants with and without orofacial clefts. Methods We used data from the National Birth Defects Prevention Study; 228 twins and 8,242 singletons without birth defects (controls), and 117 twins and 2,859 singletons with orofacial clefts, born 1997–2007, were included in the analyses. Because of the occurrence of twinning due to the use of assisted reproductive technologies, logistic regression models were computed to estimate odds ratios (OR) and 95% confidence intervals (CIs) for each exposure, stratified by fertility treatment use. To evaluate factors by zygosity, we used sex-pairing data and a simulation approach to estimate the zygosity of like-sex twin pairs for unassisted conceptions. Results Among control mothers who did not use fertility treatments, predictors of twinning included non-Hispanic black maternal race (adjusted OR: 1.6, 95% CI: 1.0–2.4), and tobacco smoking (1.6, 1.1–2.4). Among control mothers who used fertility treatments, older maternal age, higher income, and state of residence were associated with twinning. Associations were generally stronger among mothers of dizygotic (estimated) twins than monozygotic (estimated) twins. Results for mothers of infants with isolated orofacial clefts were similar to those of controls. Conclusion We observed an increased twinning frequency with increasing maternal age, but factors such as maternal race/ethnicity and socioeconomic status may also contribute. Among women receiving fertility treatments, factors associated with twinning suggested a relation with treatment specifics (e.g., treatment type and number of embryos implanted) and availability of insurance coverage. PMID:25359509

  7. Fetal Intra-Peritoneal Transfusion for the Management of Very Early Spontaneous Twin Anemia-Polycythemia Sequence in an Obese Patient With a Whole Anterior Placenta.

    PubMed

    Guenot, Cécile; Robyr, Romaine; Jastrow, Nicole; Vial, Yvan; Raio, Luigi; Baud, David

    2016-04-01

    Twin anemia-polycythemia sequence (TAPS) is a rare condition in monochorionic twin pregnancies. Small intertwin placental vascular communications allow transfusion, which results in a hemoglobin difference in the twins in the absence of oligohydramnios or polyhydramnios. We report here a case of TAPS diagnosed at 17 weeks' gestation in an obese patient (BMI 42) with a whole anterior placenta. The only possible treatment at this stage of pregnancy was intra-uterine transfusion (IUT), which was repeated weekly until photocoagulation of placental anastomoses was feasible. Fetoscopic laser surgery is the only curative treatment, but is challenging in TAPS because of the absence of polyhydramnios and the presence of minuscule anastomoses. An anterior placenta and high BMI can make the procedure even more challenging. This case report demonstrates that very early and rapidly progressing TAPS with technically complicated conditions (elevated BMI and anterior placenta) can be successfully managed with IUT until laser procedure is achievable. PMID:26996223

  8. Rapid Resolution of Polyhydramnios Foretells Circulatory Collapse for the Donor Twin in Feto-Fetal Transfusion Syndrome.

    PubMed

    López-Cepero, Ronald; Santoro, Joseph; de la Vega, Alberto

    2016-03-01

    Feto-fetal transfusion syndrome is a pathological process unique to diamniotic monochorionic pregnancies. It is the consequence of an unbalanced fetal blood flow through communicating vessels within a shared placenta. When it occurs, a polyuric, hypervolemic recipient twin co-exists with a hypovolemic oliguric donor. The presence of polyhydramnios or oligohydramnios is considered a poor prognostic indicator, whereas normal amniotic fluid volumes indicate a lack of clinically significant twintwin transfusion. In addition, the spontaneous normalization of amniotic fluid volume is usually seen as a favorable prognostic sign. Here, however, we present a case of feto-fetal transfusion in a 31 year-old primigravida at 19 week, in which the spontaneous normalization of amniotic fluid volume in the recipient twin preceded the death of the donor. PMID:26932285

  9. A Comparison of Disease Burden Between Twins and Control Pairs in Medicare: Quantification of Heredity's Role in Human Health.

    PubMed

    Sorace, James; Rogers, Michael; Millman, Michael; Rogers, Daniel; Price, Kyle; Queen, Susan; Worrall, Chris; Kelman, Jeffrey

    2015-10-01

    To quantify heredity's effects on the burden of illness in the Medicare population, this study linked information between participants in a research twin registry to a comprehensive set of Medicare claims. To calculate disease categories, the authors used the Centers for Medicare & Medicaid Services Hierarchical Conditions Categories (HCC) model that was developed to risk adjust Medicare's capitation payments to private health care plans based on the health expenditure risk of their enrollees. Using the Medicare database, 2 sets of unrelated but demographically matched control pairs (MCPs) were generated, one specific for the monozygotic twin population and the second specific for the dizygotic twin population. The concordance and correlation rates of the 70 HCC categories for the 2 twin populations, in comparison to their corresponding MCP, was then calculated using Medicare claims data from 1991 through 2011. When indicated, HCCs for which there was a statistically significant difference between the twin and corresponding MCP control group were analyzed by calculating concordance and correlation rates of the International Classification of Diseases, Ninth Revision codes that compose the HCC. Findings reveal that monozygotic twins share 6.5% more HCC disease categories than their MCP while dizygotic twins share 3.8% more HCC disease categories than their MCP. Atrial fibrillation is a highly heritable disease category, a finding consistent with prior literature describing the heritability of the cardiac arrhythmias. These findings are consistent with qualitative assessments of heredity's role found in previous models of population health, and provide both novel methods and quantitative evidence to support future model development. PMID:25658666

  10. Twin Jet

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  11. Diversity of Gut Microbiota Metabolic Pathways in 10 Pairs of Chinese Infant Twins.

    PubMed

    Zhou, Shaoming; Xu, Ruihuan; He, Fusheng; Zhou, Jiaxiu; Wang, Yan; Zhou, Jianli; Wang, Mingbang; Zhou, Wenhao

    2016-01-01

    Early colonization of gut microbiota in human gut is a complex process. It remains unclear when gut microbiota colonization occurs and how it proceeds. In order to study gut microbiota composition in human early life, the present study recruited 10 healthy pairs of twins, including five monozygotic (MZ) and five dizygotic (DZ) twin pairs, whose age ranged from 0 to 6 years old. 20 fecal samples from these twins were processed by shotgun metagenomic sequencing, and their averaged data outputs were generated as 2G per sample. We used MEGAN5 to perform taxonomic and functional annotation of the metagenomic data, and systematically analyzed those 20 samples, including Jaccard index similarity, principle component, clustering, and correlation analyses. Our findings indicated that within our study group: 1) MZ-twins share more microbes than DZ twins or non-twin pairs, 2) gut microbiota distribution is relatively stable at metabolic pathways level, 3) age represents the strongest factor that can account for variation in gut microbiota, and 4) a clear metabolic pathway shift can be observed, which speculatively occurs around the age of 1 year old. This research will serve as a base for future studies of gut microbiota-related disease research. PMID:27583441

  12. Isolation of Separate Ureaplasma Species From Endotracheal Secretions of Twin Patients.

    PubMed

    Beeton, Michael L; Maxwell, Nicola C; Chalker, Victoria J; Brown, Rebecca J; Aboklaish, Ali F; Spiller, O Brad

    2016-08-01

    Isolation of Ureaplasma spp. from preterm neonates and the association with development of bronchopulmonary dysplasia has been previously investigated. However, few studies have contrasted the nature of infection in twins. In this article, we report that dizygotic twins (1 girl, 1 boy) born at 24 weeks gestation both yielded culturable Ureaplasma from endotracheal secretions. The samples were part of a serial blind collection cohort of ventilated premature neonates, and analysis of repeat cultures showed stable, separate infections over a period of 17 and 21 days, respectively. Immunoblot and probe-specific quantitative polymerase chain reaction analysis determined that Twin 1 was solely infected with Ureaplasma parvum (specifically, serovar 6 by gene sequencing), whereas Twin 2 was solely infected with Ureaplasma urealyticum (specifically, genotype A- serovars 2, 5, and 8 by gene sequencing). Immunoblot analysis found that the major surface antigen (multiple-banded antigen) altered relative mass for both strains during the course of infection. Quantitative polymerase chain reaction analysis of extracted endotracheal aspirates confirmed no evidence of mixed infection for either twin. Failure of sentinel ventilated preterm infants on the same ward to acquire Ureaplasma infection after the first week of birth suggests no cot-to-cot transfer of Ureaplasma infection occurred. This study demonstrated not only a contrasting clinical outcome for a set of twins infected with 2 separate species of Ureaplasma, but also the first real-time demonstration of multiple-banded antigen alteration and evolution of Ureaplasma over the course of a clinical infection. PMID:27418415

  13. A Chaotic Home Environment Accounts for the Association between Respect for Rules Disposition and Reading Comprehension: A Twin Study.

    PubMed

    Taylor, Jeanette; Hart, Sara A

    2014-10-01

    This study examined the association between socioemotional dispositions from the developmental propensity model and reading comprehension and whether those associations could be accounted for by level of chaos in the home. Data from 342 monozygotic and 333 same-sex dizygotic twin pairs age 7-13 years were used. A parent rated the twins on sympathy, respect for rules, negative emotionality, and daring and level of chaos in the twins' home. Reading comprehension was measured using a state-wide school assessment. Only respect for rules significantly and uniquely predicted reading comprehension. Biometric models indicated that respect for rules was positively associated with reading comprehension via the shared environment and home chaos accounted for a significant amount of that shared environmental variance even after controlling for family income. Children with higher respect for rules have better reading comprehension scores in school and this relationship owes partly to the level of chaos in the family home. PMID:25328362

  14. Twin studies of schizophrenia: from bow-and-arrow concordances to star wars Mx and functional genomics.

    PubMed

    Cardno, A G; Gottesman, I I

    2000-01-01

    Twin studies have been vital for establishing an important genetic contribution to the etiology of schizophrenia. The five newest studies since 1995 from Europe and Japan have confirmed earlier findings. They yielded probandwise concordance rates of 41-65% in monozygotic (MZ) pairs and 0-28% in dizygotic (DZ) pairs, and heritability estimates of approximately 80-85%. Twin studies are also valuable for investigating the etiological relationships between schizophrenia and other disorders, and the genetic basis of clinical heterogeneity within schizophrenia. Studies of discordant MZ pairs provide further insights into non-inherited factors that contribute to the multifactorial etiology of this disorder. More recently, twin studies have begun to be used to directly investigate molecular genetic and epigenetic processes underlying schizophrenia. PMID:10813800

  15. A Longitudinal Twin Study of Skewed X Chromosome-Inactivation

    PubMed Central

    Wong, Chloe Chung Yi; Caspi, Avshalom; Williams, Benjamin; Houts, Renate; Craig, Ian W.; Mill, Jonathan

    2011-01-01

    X-chromosome inactivation (XCI) is a pivotal epigenetic mechanism involved in the dosage compensation of X-linked genes between males and females. In any given cell, the process of XCI in early female development is thought to be random across alleles and clonally maintained once established. Recent studies, however, suggest that XCI might not always be random and that skewed inactivation may become more prevalent with age. The factors influencing such XCI skewing and its changes over time are largely unknown. To elucidate the influence of stochastic, heritable and environmental factors in longitudinal changes in XCI, we examined X inactivation profiles in a sample of monozygotic (MZ) (n = 23) and dizygotic (DZ) (n = 22) female twin-pairs at ages 5 and 10 years. Compared to MZ twins who were highly concordant for allelic XCI ratios, DZ twins showed much lower levels of concordance. Whilst XCI patterns were moderately stable between ages 5 and 10 years, there was some drift over time with an increased prevalence of more extreme XCI skewing at age 10. To our knowledge, this study represents the earliest longitudinal assessment of skewed XCI patterns, and suggests that skewed XCI may already be established in early childhood. Our data also suggest a link between MZ twinning and the establishment of allelic XCI ratios, and demonstrate that acquired skewing in XCI after establishment is primarily mediated by stochastic mechanisms. These data have implications for our understanding about sex differences in complex disease, and the potential causes of phenotypic discordance between MZ female twins. PMID:21445353

  16. Discordant Growth of Monozygotic Twins Starts at the Blastocyst Stage: A Case Study

    PubMed Central

    Noli, Laila; Capalbo, Antonio; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2015-01-01

    Summary Discordant growth is a common complication of monochorionic/diamniotic pregnancies; in approximately 50% of cases, the cause is unknown. The case presented here suggests that discordant growth of monozygotic twins could start during preimplantation development. Two inner cell masses (ICMs) within the same blastocyst may originate in uneven splitting of a single “parental” ICM, or the two ICMs may be formed independently de novo. We studied the transcriptomes of two morphologically distinct ICMs within a single blastocyst using high-resolution RNA sequencing. The data indicated that the two ICM were at different stages of development; one was in the earliest stages of lineage commitment, while the other had already differentiated into epiblast and primitive endoderm. IGF1-mediated signaling is likely to play a key role in ICM growth and to be the major driver behind these differences. PMID:26584541

  17. Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project.

    PubMed

    Jelenkovic, Aline; Yokoyama, Yoshie; Sund, Reijo; Honda, Chika; Bogl, Leonie H; Aaltonen, Sari; Ji, Fuling; Ning, Feng; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Tarnoki, Adam D; Tarnoki, David L; Haworth, Claire M A; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Rijsdijk, Fruhling; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Kim, Bia; Chong, Youngsook; Hong, Changhee; Shin, Hyun Jung; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth J F; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos C E M; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Rasmussen, Finn; Hur, Yoon-Mi; Boomsma, Dorret I; Sørensen, Thorkild I A; Kaprio, Jaakko; Silventoinen, Karri

    2015-10-01

    A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes. PMID:26337138

  18. Does Caregiving Cause Psychological Distress? The Case for Familial and Genetic Vulnerabilities in Female Twins

    PubMed Central

    Vitaliano, Peter P.; Strachan, Eric; Dansie, Elizabeth; Goldberg, Jack; Buchwald, Dedra

    2014-01-01

    Background Informal caregiving can be deleterious to mental health, but research results are inconsistent and may reflect an interaction between caregiving and vulnerability to stress. Methods We examined psychological distress among 1,228 female caregiving and non-caregiving twins. By examining monozygotic and dizygotic twin pairs discordant for caregiving, we assessed the extent to which distress is directly related to caregiving or confounded by common genes and environmental exposures. Results Caregiving was associated with distress as measured by mental health functioning, anxiety, perceived stress, and depression. The overall association between caregiving and distress was confounded by common genes and environment for mental health functioning, anxiety, and depression. Common environment also confounded the association of caregiving and perceived stress. Conclusions Vulnerability to distress is a factor in predicting caregivers' psychosocial functioning. Additional research is needed to explicate the mechanisms by which common genes and environment increase the risk of distress among informal caregivers. PMID:24264772

  19. Visuo-spatial and linguistic abilities in a twin with Williams syndrome.

    PubMed

    Volterra, V; Longobardi, E; Pezzini, G; Vicari, S; Antenore, C

    1999-08-01

    The present study reports a case of dizygotic twins, one boy with Williams syndrome (WS) and one typically developing girl, and compares their neuropsychological profiles. The goal of the present authors was to verify whether the child with WS displayed a cognitive profile which is unique to the syndrome. Several tests designed to assess visuo-perceptual, visuo-motor, linguistic and memory abilities were administered to both children when they were 10.9 years old. Compared to his sister, the boy with WS displayed a homogeneous developmental delay in both non-verbal and verbal abilities. He achieved a level of performance similar to his sister only in facial recognition, phonological word fluency and memory for phonologically similar words. Furthermore, despite the overall delayed performance of the boy, both the twins displayed a cognitive profile characterized by strength in lexical comprehension and relative weakness in visuo-motor abilities. PMID:10466868

  20. Multiple regression analysis of reading performance data from twin pairs with reading difficulties and nontwin siblings: the augmented model.

    PubMed

    Wadsworth, Sally J; Olson, Richard K; Willcutt, Erik G; DeFries, John C

    2012-02-01

    The augmented multiple regression model for the analysis of data from selected twin pairs was extended to facilitate analyses of data from twin pairs and nontwin siblings. Fitting this extended model to data from both selected twin pairs and siblings yields direct estimates of heritability (h2) and the difference between environmental influences shared by members of twin pairs and those of sib or twin-sib pairs (i.e., c2(t) - c2 (s)). When this model was fitted to reading performance data from 293 monozygotic and 436 dizygotic pairs selected for reading difficulties, and 291 of their nontwin siblings, h2 = .48 ± .22, p = .03, and c2 (t) - c2 (s) = .22 ± .12, p = .06. Although the test for differential shared environmental influences is only marginally significant, the results of this analysis suggest that environmental influences on reading performance that are shared by members of twin pairs (.36) may be substantially greater than those for less contemporaneous twin-sibling pairs (.14). PMID:22784461

  1. The TRAP (twin reversed arterial perfusion) sequence - case presentation.

    PubMed

    Mărginean, Claudiu; Mărginean, Maria Oana; Mureşan, Daniel; Zahiu, LuminiŢa; Horváth, Emőke

    2016-01-01

    We present a particular case of TRAP (twin reversed arterial perfusion) syndrome, which has a very rarely association of the simultaneous existence of a rudimentary malformed heart and brain, and also other malformations like abdominal wall abnormality, absent bladder with present kidneys, and absence of the lungs, which appear only in a few cases on the receptor twin from this sequence, malformations incompatible with life. A Caucasian 26-year-old pregnant woman, at the first pregnancy, with a monochorionic-diamniotic pregnancy, 26 weeks of gestation was referred to our hospital, for polyhydramnios. The patient delivered a living female newborn, weighing 950 g, with an Apgar score of 2 at one minute - the donor fetus and a second female newborn with multiple malformations, no signs of life and who weighed 2300 g - the receptor fetus. The anatomopathological examination confirmed the TRAP sequence associated with severe facial dysmorphism, bilateral phocomelia and cardiac malformations (rudimentary hypoplastic, univentricular) and a vascular anastomosis between the two umbilical cords. Anemia and cardiac complications which can lead to cardiac failure, appear early during pregnancy and caused the death of the pumping twin. We emphasize that in our case of TRAP sequence, the ultrasound examination established the diagnosis of the syndrome with high accuracy. Therefore, we can conclude that the existence of a rudimentary heart and a vascular anastomosis between the two umbilical cords supports the apparition of TRAP sequence. The early diagnosis of this pathology, the observation of the pregnancy with the help of weekly ultrasounds and the intrauterine interventions can increase the survival chances of the donor fetus from the TRAP sequence. PMID:27151718

  2. Deformation twins in Hornblende

    USGS Publications Warehouse

    Rooney, T.P.; Riecker, R.E.; Ross, M.

    1970-01-01

    Hornblende deformation twins with twin planes parallel to (101) are produced experimentally in single crystals by compression parallel to the c axis. Twinning occurs at confining pressures from 5 to 15 kilobars and temperatures from 400?? to 600??C (strain rate, 10-5 per second).

  3. The association between hippocampal volume and life events in healthy twins.

    PubMed

    Bootsman, Florian; Kemner, Sanne M; Hillegers, Manon H J; Brouwer, Rachel M; Vonk, Ronald; van der Schot, Astrid C; Hulshoff Pol, Hilleke E; Nolen, Willem A; Kahn, René S; van Haren, Neeltje E M

    2016-08-01

    Hippocampal volume deficits have been linked to life stress. However, the degree to which genes and environment influence the association between hippocampal volume and life events is largely unknown. In total, 123 healthy twins from monozygotic and dizygotic twin pairs underwent magnetic resonance imaging (MRI), and 57 healthy twins were interviewed with the Life Events and Difficulties Schedule (LEDS), with an overlap of 54 twins undergoing both MRI and the life events interview. Hippocampal volumes were segmented with Freesurfer software. Data were analyzed with OpenMx software. Smaller hippocampal volume was associated with higher severe life event load (rph = -0.39), where shared environmental factors influencing both measures fully explained the association. Hippocampal volume was not associated with total or mild life event load. Hippocampal volume showed high heritability (range, h(2) : 57%-81%) whereas life event measures were influenced by shared (c(2) ) and unique (e(2) ) environmental factors only (range, c(2) :40%-64%, e(2) : 36%-60%). The results suggested that shared environmental factors influenced the relationship between smaller hippocampal volume and severe (but not mild) stress. This indicated that particularly severe life events that were shared between twins were associated with smaller hippocampal volume. Furthermore, it is suggested to distinguish between mild and severe life events in life event research. © 2016 Wiley Periodicals, Inc. PMID:27010665

  4. Genetic and Environmental Influences on the Mental Health of Children: A Twin Study.

    PubMed

    Yin, Ping; Hou, Xiao; Qin, Qing; Deng, Wei; Hu, Hua; Luo, Qinghua; Du, Lian; Qiu, Haitang; Qiu, Tian; Fu, Yixiao; Meng, Huaqing; Li, Tao

    2016-08-01

    The current study explored the influences of genetic and environmental factors on the mental health of twins between ages 6 and 16. A total of 41 monozygotic (MZ) twins and 35 dizygotic twins were recruited. The psychological attributes and environmental information of children were evaluated. A significant correlation was found between twins in the diagnostic categories of any psychiatric disorder and attention deficit/hyperactivity disorder (ADHD)/hyperkinesis based on the Strengths and Difficulties Questionnaire scale in MZ twins. Furthermore, fathers' authoritarian parenting style was positively correlated with the probability of any psychiatric disorders and oppositional/conduct disorders, whereas mothers' authoritative parenting style was negatively correlated with the probability of any psychiatric disorders and ADHD/hyperkinesis. The probability of emotional disorders was negatively correlated with scores on the Stressful Life Events Scale. These results collectively suggest that genetic and environmental elements, such as parental rearing style and stressful life events, may influence children's mental health. [Journal of Psychosocial Nursing and Mental Health Services, 54(8), 29-34.]. PMID:27479477

  5. Prevalence of and Familial Influences on Purging Disorder in a Community Sample of Female Twins

    PubMed Central

    Munn-Chernoff, Melissa A.; Keel, Pamela K.; Klump, Kelly L.; Grant, Julia D.; Bucholz, Kathleen K.; Madden, Pamela A. F.; Heath, Andrew C.; Duncan, Alexis E.

    2014-01-01

    Objective Purging Disorder (PD) was recently included as an Otherwise Specified Feeding or Eating Disorder (OSFED) in the DSM-5; however, limited information is available on its prevalence, and its etiology is unknown. Method Data from 1790 monozygotic and 1440 dizygotic European American female twins (age range = 18 – 29 years) from the Missouri Adolescent Female Twin Study were used to investigate prevalence and familial influences for PD. A structured clinical interview assessed lifetime DSM-IV criteria for eating disorders and PD. After adjustment for age, twin correlations and biometrical twin models were used to estimate familial (i.e., genetic plus shared environmental) influences on PD. Results One hundred and twenty one (3.77%; 95% CI: 3.14, 4.49) women met criteria for lifetime PD. Twin correlations suggested that genetic, shared environmental, and nonshared environmental factors influenced liability to PD. Nonshared environmental factors accounted for 56% [35%, 79%] of the variance in PD. Although familial effects accounted for a significant proportion of variance (44% [21%, 65%]), it was not possible to disentangle the independent contributions of additive genetic effects (20% [0%, 65%]) and shared environmental effects (24% [0%, 57%]). Discussion PD is a prevalent form of eating pathology. Familial factors are relevant to the development of PD but do not demonstrate the magnitude of heritable factors found for other eating disorders. PMID:25808399

  6. Cohort Profile: Swedish Twin Study on Prediction and Prevention of Asthma (STOPPA).

    PubMed

    Almqvist, Catarina; Örtqvist, Anne K; Ullemar, Vilhelmina; Lundholm, Cecilia; Lichtenstein, Paul; Magnusson, Patrik K E

    2015-06-01

    Asthma is a common childhood disease and several risk factors have been identified; however, the impact of genes and environment is not fully understood. The aim of the Swedish Twin study On Prediction and Prevention of Asthma (STOPPA) is to identify environmental (birth characteristics and early life) and genetic (including epigenetic) factors as determinants for asthmatic disease. Based on the Child and Adolescent Twin Study in Sweden (CATSS) (parental interview at 9 or 12 years, N ~23,900) and an asthma and/or wheezing algorithm, we identified a sample of monozygotic (MZ) and dizygotic (DZ) same-sexed twin pairs. The twin pairs were classified as asthma concordant (ACC), asthma discordant (ADC) and healthy concordant (HCC). A sample of 9- to 14-year-old twins and their parents were invited to participate in a clinical examination. Background characteristics were collected in questionnaires and obtained from the National Health Registers. A clinical examination was performed to test lung function and capacity (spirometry with reversibility test and exhaled nitric oxide) and collect blood (serology and DNA), urine (metabolites), feces (microbiota), and saliva (cortisol). In total, 376 twin pairs (752 individual twins) completed the study, response rate 52%. All participating twins answered the questionnaire and >90% participated in lung function testing, blood-, and saliva sampling. This article describes the design, recruitment, data collection, measures, and background characteristics, as well as ongoing and planned analyses in STOPPA. Potential gains of the study include the identification of biomarkers, the emergence of candidates for drug development, and new leads for prevention of asthma and allergic disease. PMID:25900604

  7. Asymmetric twin Dark Matter

    SciTech Connect

    Farina, Marco

    2015-11-09

    We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.

  8. Merohedral twins revisited: quinary twins and beyond.

    PubMed

    Quiquandon, Marianne; Gratias, Denis; Sirindil, Abdullah; Portier, Richard

    2016-01-01

    A twin is defined as being an external operation between two identical crystals that share a fraction of the atomic structure with no discontinuity from one crystal to the other. This includes merohedral twins, twins by reticular merohedry as well as coherent twins by contact where only the habit plane is shared by the two adjacent crystals (epitaxy). Interesting and original cases appear when the invariant substructure is built with positions belonging to the same {\\bb Z}-module as, for example, the quinary twin structure first drawn by Albrecht Dürer [(1525). The Painter's Manual: a Manual of Measurement of Lines, Areas and Solids by Means of Compass and Ruler. Facsimile Edition (1977), translated with commentary by W. L. Strauss. New York: Abaris Books]. This paper will show that the Dürer twins, once defined in five-dimensional space, are simple merohedral twins, in the sense of Georges Friedel, leaving the five-dimensional lattice invariant. This analysis will be generalized to some other higher-order {\\bb Z}-modules. PMID:26697867

  9. Physically active vs. inactive lifestyle, muscle properties, and glucose homeostasis in middle-aged and older twins.

    PubMed

    Leskinen, T; Sipilä, S; Kaprio, J; Kainulainen, H; Alen, M; Kujala, U M

    2013-10-01

    Exercise-induced positive changes in skeletal muscle properties and metabolism decrease the risk for disability, cardiometabolic diseases and mortality. Here, we studied muscle properties and glucose homeostasis in a non-exercise stage in twin pairs with co-twins discordant for physical activity habits for at least 32 years of their adult lives. Isometric knee extension force, MR imaging of midthigh tissue composition and muscle volume, and fasting blood samples were acquired from 16 same-sex (seven monozygotic, nine dizygotic) middle-aged and older twin pairs. The consistently active twins had 20 % higher knee extension forces than their inactive co-twins (p = 0.006) although the active twins had only 4 % higher midthigh muscle cross-sectional areas (p = 0.072). These results were similar in intrapair analysis in which only the seven identical twin pairs were included. The ratio between the area of midthigh fat and muscle tissues was significantly lower among the active twins (0.65 vs. 0.48, p = 0.006). The active twins had also lower fasting plasma glucose levels (5.1 vs 5.6 mmol/l, p = 0.041). The area of midthigh intramuscular (extramyocellular) fat was associated with the markers of glucose homeostasis, especially with glycated hemoglobin, and these associations were emphasized by the diabetic and inactive twins. Regular exercise throughout the adult life retains muscle strength and quality but not necessarily mass. The regular use of muscles also prevents from the accumulation of intramuscular fat which might be related to maintained glucose metabolism and, thus, prevention of metabolic disorders. PMID:23124702

  10. Body Mass Index and Depressive Symptoms: Testing for Adverse and Protective Associations in Two Twin Cohort Studies.

    PubMed

    Jokela, Markus; Berg, Venla; Silventoinen, Karri; Batty, G David; Singh-Manoux, Archana; Kaprio, Jaakko; Davey Smith, George; Kivimäki, Mika

    2016-08-01

    Studies have suggested both adverse and protective associations of obesity with depressive symptoms. We examined the contribution of environmental and heritable factors in this association. Participants were same-sex twin pairs from two population-based twin cohort studies, the Older Finnish Twin Cohort (n = 8,215; mean age = 44.1) and the US Midlife Development in the United States (MIDUS; n = 1,105; mean age = 45.1). Body mass index (BMI) was calculated from self-reported height and weight. Depressive symptoms were assessed using Beck's Depression Inventory (BDI; Finnish Twin Cohort), and by negative and positive affect scales (MIDUS). In the Finnish Twin Cohort, higher BMI was associated with higher depressive symptoms in monozygotic (MZ) twins (B = 2.01, 95% CI = 1.0, 3.0) and dizygotic (DZ) twins (B = 1.17, 0.5, 1.9) with BMI >22. This association was observed in within-pair analysis in DZ twins (B = 1.47, CI = 0.4, 2.6) but not in within-pair analysis of MZ twins (B = 0.03, CI = -1.9, 2.0). Consistent with the latter result, a bivariate genetic model indicated that the association between higher BMI and higher depressive symptoms was largely mediated by genetic factors. The results of twin-pair analysis and bivariate genetic model were replicated in the MIDUS sample. These findings suggest an association between obesity and higher depressive symptoms, which is largely explained by shared heritable biological mechanisms. PMID:27055784

  11. One CNV Discordance in NRXN1 Observed Upon Genome-wide Screening in 38 Pairs of Adult Healthy Monozygotic Twins.

    PubMed

    Magnusson, Patrik K E; Lee, Donghwan; Chen, Xu; Szatkiewicz, Jin; Pramana, Setia; Teo, Shumei; Sullivan, Patrick F; Feuk, Lars; Pawitan, Yudi

    2016-04-01

    Monozygotic (MZ) twins stem from the same single fertilized egg and therefore share all their inherited genetic variation. This is one of the unequivocal facts on which genetic epidemiology and twin studies are based. To what extent this also implies that MZ twins share genotypes in adult tissues is not precisely established, but a common pragmatic assumption is that MZ twins are 100% genetically identical also in adult tissues. During the past decade, this view has been challenged by several reports, with observations of differences in post-zygotic copy number variations (CNVs) between members of the same MZ pair. In this study, we performed a systematic search for differences of CNVs within 38 adult MZ pairs who had been misclassified as dizygotic (DZ) twins by questionnaire-based assessment. Initial scoring by PennCNV suggested a total of 967 CNV discordances. The within-pair correlation in number of CNVs detected was strongly dependent on confidence score filtering and reached a plateau of r = 0.8 when restricting to CNVs detected with confidence score larger than 50. The top-ranked discordances were subsequently selected for validation by quantitative polymerase chain reaction (qPCR), from which one single ~120kb deletion in NRXN1 on chromosome 2 (bp 51017111-51136802) was validated. Despite involving an exon, no sign of cognitive/mental consequences was apparent in the affected twin pair, potentially reflecting limited or lack of expression of the transcripts containing this exon in nerve/brain. PMID:26899349

  12. Are differences between twins a result of mutual rivalry?

    PubMed

    Borg, J G

    1997-01-01

    The sexual index included in the Szondi test makes it possible to define the domains of an individual's "internal sex" or gender-especially the degree of the subject's bisexuality. This index was employed in a comparison between partners reared together in 62 monozygotic and 23 dizygotic pairs of twins. The observed incongruence in 1/3 MZ pairs would not appear to derive totally from errors of measurement. In most of these pairs it is competition which underlies the incongruence seen on the sexual index. It was further observed that the congruence here as in general in female pairs is clearly more marked than in males. A hypothesis was proposed, whereby competition for dominance is a distinctively major-tonality (masculinity) characteristic. The incongruence is more conspicuous among males because males are in general more markedly major-toned than females. This hypothesis was borne out. It is thus necessary here as in general to adopt two sex variables in parallel: external (i.e. matricular) sex and internal sex (gender). It is due to the presence of these competitive pairs that the means and especially deviations of twins' test results will consistently diverge from those in the population at large. PMID:9298156

  13. Twin-to-twin transfusion syndrome

    MedlinePlus Videos and Cool Tools

    ... multiples that share a single placenta containing blood vessels going from one baby to the other. Blood ... transferred to the larger "recipient" twin through interconnecting vessels causing an unequal exchange of blood. The recipient ...

  14. Is Chronic Low Back Pain Associated with the Prevalence of Coronary Heart Disease when Genetic Susceptibility Is Considered? A Co-Twin Control Study of Spanish Twins

    PubMed Central

    Fernandez, Matt; Ordoñana, Juan R.; Hartvigsen, Jan; Ferreira, Manuela L.; Refshauge, Kathryn M.; Sánchez-Romera, Juan F.; Pinheiro, Marina B.; Simpson, Stephen J.; Hopper, John L.; Ferreira, Paulo H.

    2016-01-01

    Objective To investigate the chronic low back pain and coronary heart disease relationship, after adjusting for relevant confounders, including genetics. Methods In a cross-sectional design, 2148 twins were recruited from the Murcia Twin Registry, Spain. The exposure was chronic LBP and the outcomes were myocardial infarction and other coronary heart diseases—lifetime and in the last 2 years–based on standardized health-related questionnaires. First, logistic regression analysis investigated associations of the total sample followed by a matched co-twin control analyses, with all complete twin pairs discordant for chronic LBP utilised, separated for zygosity—dizygotic (DZ) and monozygotic (MZ) pairs, which adjusted for shared familial factors, including genetics. Results Chronic LBP pain is associated with lifetime myocardial infarction [odds ratio (OR) = 2.69, 95% confidence interval (CI) = 1.35–5.36], other coronary heart diseases over a lifetime (OR = 2.58, 95% CI: 1.69–3.93) and in the last two years (OR = 2.19, 95% CI: 1.33–3.60), while there was a borderline association with myocardial infarction in the last 2 years (OR = 2.64, 95% CI: 0.98–7.12). Although the magnitude of the association remained or increased in the co-twin control analyses, none reached statistical significance. Conclusion Chronic LBP is associated with a higher prevalence of myocardial infarction and coronary heart disease. It is possible that this association remains even when controlling for genetics and early shared environment, although this should be investigated with larger samples of twins discordant for LBP. PMID:27171210

  15. More physics twins

    NASA Astrophysics Data System (ADS)

    Shemilt, Jane; Hodge, Alison; White, Martin; Dewhurst, Samuel; Evans, Colin J.; Smith, Ron

    2008-02-01

    Your article about the two female physicists in Israel (pictured above) who are identical twins raised the question of whether any other such twins exist (January p3). My identical twin sister and I were both undergraduates at Imperial College, being in the first cohort of students to graduate in materials science in 1973. This was under our maiden names of Jane and Ruth Weston.

  16. Associations Between Fast-Food Consumption and Body Mass Index: A Cross-Sectional Study in Adult Twins.

    PubMed

    Cohen-Cline, Hannah; Lau, Richard; Moudon, Anne V; Turkheimer, Eric; Duncan, Glen E

    2015-08-01

    Obesity is a substantial health problem in the United States, and is associated with many chronic diseases. Previous studies have linked poor dietary habits to obesity. This cross-sectional study aimed to identify the association between body mass index (BMI) and fast-food consumption among 669 same-sex adult twin pairs residing in the Puget Sound region around Seattle, Washington. We calculated twin-pair correlations for BMI and fast-food consumption. We next regressed BMI on fast-food consumption using generalized estimating equations (GEE), and finally estimated the within-pair difference in BMI associated with a difference in fast-food consumption, which controls for all potential genetic and environment characteristics shared between twins within a pair. Twin-pair correlations for fast-food consumption were similar for identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins, but were substantially higher in MZ than DZ twins for BMI. In the unadjusted GEE model, greater fast-food consumption was associated with larger BMI. For twin pairs overall, and for MZ twins, there was no association between within-pair differences in fast-food consumption and BMI in any model. In contrast, there was a significant association between within-pair differences in fast-food consumption and BMI among DZ twins, suggesting that genetic factors play a role in the observed association. Thus, although variance in fast-food consumption itself is largely driven by environmental factors, the overall association between this specific eating behavior and BMI is largely due to genetic factors. PMID:26005202

  17. A twin study of breastfeeding with a preliminary genome wide association scan

    PubMed Central

    Colodro-Conde, L.; Zhu, G.; Power, R. A.; Henders, A.; Heath, A.C.; Madden, P.A.F.; Montgomery, G.W.; Medland, S. E.; Ordoñana, J.R.; Martin, N.G.

    2015-01-01

    Breastfeeding has been an important survival trait during human history, though it has long been recognised that individuals differ in their exact breastfeeding behaviour. Here our aims were, first, to explore to what extent genetic and environmental influences contributed to the individual differences in breastfeeding behaviour; second, to detect possible genetic variants related to breastfeeding; and lastly, to test if the genetic variants associated with breastfeeding have been previously found to be related with breast size. Data were collected from a large community-based cohort of Australian twins, with 3,364 women for the twin modelling analyses and 1,521 of them included in the genome wide association study. Monozygotic twin correlations (rMZ = .52, 95% CI .46 – .57) were larger than dizygotic twin correlations (rDZ = .35, 95% CI .25 – .43) and the best-fitting model was the one composed by additive genetics and unique environmental factors, explaining 53% and 47% of the variance in breastfeeding behaviour, respectively. No breastfeeding-related genetic variants reached genome-wide significance. The polygenic risk score analyses showed no significant results, suggesting breast size does not influence breastfeeding. This study confers a replication of a previous one exploring the sources of variance of breastfeeding and, to our knowledge, is the first one to conduct a Genome-Wide Association Study on breastfeeding and look at the overlap with variants for breast size. PMID:25475840

  18. A twin and molecular genetics study of sleep paralysis and associated factors.

    PubMed

    Denis, Dan; French, Christopher C; Rowe, Richard; Zavos, Helena M S; Nolan, Patrick M; Parsons, Michael J; Gregory, Alice M

    2015-08-01

    Sleep paralysis is a relatively common but under-researched phenomenon. In this paper we examine prevalence in a UK sample and associations with candidate risk factors. This is the first study to investigate the heritability of sleep paralysis in a twin sample and to explore genetic associations between sleep paralysis and a number of circadian expressed single nucleotide polymorphisms. Analyses are based on data from the Genesis1219 twin/sibling study, a community sample of twins/siblings from England and Wales. In total, data from 862 participants aged 22-32 years (34% male) were used in the study. This sample consisted of monozygotic and dizygotic twins and siblings. It was found that self-reports of general sleep quality, anxiety symptoms and exposure to threatening events were all associated independently with sleep paralysis. There was moderate genetic influence on sleep paralysis (53%). Polymorphisms in the PER2 gene were associated with sleep paralysis in additive and dominant models of inheritance-although significance was not reached once a Bonferroni correction was applied. It is concluded that factors associated with disrupted sleep cycles appear to be associated with sleep paralysis. In this sample of young adults, sleep paralysis was moderately heritable. Future work should examine specific polymorphisms associated with differences in circadian rhythms and sleep homeostasis further in association with sleep paralysis. PMID:25659590

  19. Improving fluid registration through white matter segmentation in a twin study design

    NASA Astrophysics Data System (ADS)

    Chou, Yi-Yu; Lepore, Natasha; Brun, Caroline; Barysheva, Marina; McMahon, Katie; de Zubicaray, Greig I.; Wright, Margaret J.; Toga, Arthur W.; Thompson, Paul M.

    2010-03-01

    Robust and automatic non-rigid registration depends on many parameters that have not yet been systematically explored. Here we determined how tissue classification influences non-linear fluid registration of brain MRI. Twin data is ideal for studying this question, as volumetric correlations between corresponding brain regions that are under genetic control should be higher in monozygotic twins (MZ) who share 100% of their genes when compared to dizygotic twins (DZ) who share half their genes on average. When these substructure volumes are quantified using tensor-based morphometry, improved registration can be defined based on which method gives higher MZ twin correlations when compared to DZs, as registration errors tend to deplete these correlations. In a study of 92 subjects, higher effect sizes were found in cumulative distribution functions derived from statistical maps when performing tissue classification before fluid registration, versus fluidly registering the raw images. This gives empirical evidence in favor of pre-segmenting images for tensor-based morphometry.

  20. Heritability and heteromorphic distributions of AluI chromosome banding variants in twins

    SciTech Connect

    Huang, B.; Meyer, J.M.; Jackson-Cook, C.K.

    1995-07-03

    The heritability and heteromorphic appearance of chromosomal banding patterns induced through in situ digestion with the restriction enzyme AluI were studied by analyzing the chromosomes of 25 monozygotic and 25 dizygotic twin pairs selected at random from a juvenile twin registry. A total of 19 AluI banding variants were found to be heteromorphic, with the pericentromeric region of chromosome 3 and the satellites of chromosome 22 being most and least heteromorphic, respectively. As expected, the correlations of the semi-quantitative scores for each of the chromosomal variants were significantly higher between MZ twin pairs (ranging from 0.48 to 0.95) than DZ twin pairs (ranging from -0.02 to 0.69), suggesting that genetic factors play an important role in their appearance. This finding was confirmed in a model fitting analysis in which the heritabilities of the AluI-induced chromosome variants were found to range from 70 to 96% for 12/13 heteromorphisms studied. These consistent findings are significant in that these variants may be useful for family studies in clinical genetics. 23 refs., 6 figs., 3 tabs.

  1. A Study of Sedentary Behaviour in the Older Finnish Twin Cohort: A Cross Sectional Analysis

    PubMed Central

    Kaprio, Jaakko

    2014-01-01

    The aim of the study was to investigate the effects of age, sex, and body mass index (BMI) on total sitting time among the Finnish twin cohort. Also, heritability and environmental factors were analysed. The final sample included 6713 twin individuals 53–67 years of age (46% men). Among them there were 1940 complete twin pairs (732 monozygotic [MZ] and 1208 dizygotic [DZ] twin pairs). Sedentary behaviour was queried with a self-reported questionnaire with multiple-choice questions about sitting time at different domains. The mean total sitting time per day was 6 hours 41 minutes (standard deviation: 2 hours 41 minutes). The total sitting time was less in women than in men (P = 0.002). Older age was associated with less total sitting time (P < 0.001). Those with higher body mass index had higher total sitting time in age and sex adjusted analysis (P < 0.001). MZ pairs were more similar for sitting time than DZ pairs, with initial estimates of heritability for the total sitting time of 35%.The influence of shared environmental factors was negligible (1%), while most (64%) of the variation could be ascribed to unique environmental factors, the latter including measurement error. PMID:24822182

  2. A study of diabetes mellitus within a large sample of Australian twins.

    PubMed

    Condon, Julianne; Shaw, Joanne E; Luciano, Michelle; Kyvik, Kirsten O; Martin, Nicholas G; Duffy, David L

    2008-02-01

    Twin studies of diabetes mellitus can help elucidate genetic and environmental factors in etiology and can provide valuable biological samples for testing functional hypotheses, for example using expression and methylation studies of discordant pairs. We searched the volunteer Australian Twin Registry (19,387 pairs) for twins with diabetes using disease checklists from nine different surveys conducted from 1980-2000. After follow-up questionnaires to the twins and their doctors to confirm diagnoses, we eventually identified 46 pairs where one or both had type 1 diabetes (T1D), 113 pairs with type 2 diabetes (T2D), 41 female pairs with gestational diabetes (GD), 5 pairs with impaired glucose tolerance (IGT) and one pair with MODY. Heritabilities of T1D, T2D and GD were all high, but our samples did not have the power to detect effects of shared environment unless they were very large. Weight differences between affected and unaffected cotwins from monozygotic (MZ) discordant pairs were large for T2D and GD, but much larger again for discordant dizygotic (DZ) pairs. The bivariate genetic analysis (under the multifactorial threshold model) estimated the genetic correlation between body mass index (BMI) and T2D to be 0.46, and the environmental correlation at only 0.06. PMID:18251672

  3. A Chaotic Home Environment Accounts for the Association between Respect for Rules Disposition and Reading Comprehension: A Twin Study

    PubMed Central

    Taylor, Jeanette; Hart, Sara A.

    2014-01-01

    This study examined the association between socioemotional dispositions from the developmental propensity model and reading comprehension and whether those associations could be accounted for by level of chaos in the home. Data from 342 monozygotic and 333 same-sex dizygotic twin pairs age 7-13 years were used. A parent rated the twins on sympathy, respect for rules, negative emotionality, and daring and level of chaos in the twins’ home. Reading comprehension was measured using a state-wide school assessment. Only respect for rules significantly and uniquely predicted reading comprehension. Biometric models indicated that respect for rules was positively associated with reading comprehension via the shared environment and home chaos accounted for a significant amount of that shared environmental variance even after controlling for family income. Children with higher respect for rules have better reading comprehension scores in school and this relationship owes partly to the level of chaos in the family home. PMID:25328362

  4. Patterns and sources of continuity and change of energetic and temporal aspects of temperament in adulthood: A longitudinal twin study of self- and peer reports.

    PubMed

    Kandler, Christian; Riemann, Rainer; Angleitner, Alois

    2013-09-01

    This study investigated the mean-level and individual-level trends as well as the genetic and environmental sources of rank-order continuity and change in temperament traits (Briskness, Perseveration, Sensory Sensitivity, Emotional Reactivity, Endurance, and Activity). We analyzed self-reports and peer ratings from 2 adult age groups of twins, aged 15-30 (n = 348; 113 monozygotic and 61 dizygotic twin pairs) and 31-67 (n = 352; 110 monozygotic and 66 dizygotic twin pairs), captured at 2 different points of time 13 years apart. Temperament traits were fairly stable accompanying high levels of heritability. However, they also undergo mean-level, individual-level, and rank-order changes. In young adulthood, rank-order change was due to both genetic and environmental factors, whereas in older adult years, rank-order change was predominantly attributable to environmental effects. Phenotypic rank-order continuity was larger for older adults due to higher genetic as well as environmental continuity. For specific temperament traits (e.g., Activity), environmental variance proportionally increased across adulthood compared with genetic variance resulting in decreasing levels of heritability, whereas the reverse was found for other traits (e.g., Endurance). Specifics regarding the traits studied were discussed. The results indicate a complex interplay between genetic and environmental sources resulting in continuity and change of temperament across adulthood. PMID:23148934

  5. Guidelines on Library Twinning.

    ERIC Educational Resources Information Center

    Doyle, Robert P., Comp.; Scarry, Patricia, Comp.

    This document serves as an overview of the many forms of library twinning, or formal exchanges of materials and/or staff between two institutions. Twinning can be reciprocal, but often involves a one-way arrangement whereby a library in a developing country receives a visit from a librarian of a developed country. Either way, both institutions can…

  6. The Relationship Among Genetic Heritability, Environmental Effects, and Autism Spectrum Disorders: 37 Pairs of Ascertained Twin Study.

    PubMed

    Deng, Wenlin; Zou, Xiaobing; Deng, Hongzhu; Li, Jianying; Tang, Chun; Wang, Xueqin; Guo, Xiaobo

    2015-11-01

    Autism spectrum disorders (ASD) comprise a heterogeneous group of neurodevelopmental disorders that have strong heritability. To better understand the heritable factors in twins with clinically diagnosed ASD and to discuss the relationship between social impairments and genetic and environmental factors. In last 13 years, over 12,000 cases of ASD were diagnosed in the children's development and behavior center, the authors review 37 pairs of these twins, in each pair, and at least 1 twin had been diagnosed with an ASD, and found that the concordance rate was 80% [95% confidence interval (CI) 51.9-95.7%] for monozygotic twins and 13.6% (95% CI: 2.9-34.9%) for dizygotic twins. The heritability of social impairments for ASD was 60.9% (95% CI: 47.3-74.5%). In addition, the rate of nonshared environmental factors was 39.1% (95% CI: 25.5-52.7%), and there were no shared environmental effects. Genetics and special environmental effect play an important role on ASD social impairments. PMID:25873587

  7. Psychiatric Morbidity is Linked to Problem Drinking in Midlife Among Alcohol-Dependent Men: A Co-Twin Control Study

    PubMed Central

    Blonigen, Daniel M.; Burroughs, Thomas; Haber, Jon Randolph; Jacob, Theodore

    2013-01-01

    Objective: Prior research on predictors of problem drinking has been limited because of an inability to attribute an unambiguous environmental explanation to observed findings. Using a prospective co-twin control design, we examined the extent to which a history of psychiatric symptoms exerts an environmental influence on problem drinking in midlife that is unconfounded by genetic underpinnings. Method: Participants were 367 complete male twin pairs (208 monozygotic, 159 dizygotic) from the Vietnam Era Twin Registry who were assessed in midlife as part of the Family Twin Study (Mage = 51.4 years, SD = 2.8). Twin pairs who were concordant for a lifetime diagnosis of an alcohol use disorder (AUD) in 1992 were selected for participation and were reinterviewed in 2001 to measure symptoms of AUD (i.e., problem drinking) since the prior assessment (past 10 years). Results: Within-pair differences in lifetime symptom counts of several psychiatric disorders measured in 1992 (i.e., major depression, dysthymia, generalized anxiety disorder, panic disorder, antisocial personality, mania, and posttraumatic stress disorder) were significantly associated with within-pair differences in AUD symptoms in the subsequent 10 years. Conclusions: A history of psychiatric problems, particularly one marked by internalizing symptoms, appears to be linked to problem drinking in midlife above and beyond the confounding influence of genetic effects and underscores the potential value of integrated interventions for comorbidity to address problem drinking among individuals during this period of the life course. PMID:23200159

  8. Heritability of thyroid peroxidase autoantibody levels in type 1 diabetes: evidence from discordant twin pairs

    PubMed Central

    Wang, Bin; Hawa, Mohammed I.; Rijsdijk, Frühling V.; Fain, Pamela R.; Paschou, Stavroula A.; Boehm, Bernhard O.; Steck, Andrea K.; Snieder, Harold

    2016-01-01

    Aims/hypothesis The discordance status of (autoimmune) type 1 diabetes within monozygotic twin pairs points to the importance of environmental factors. The aim of this study was to investigate whether the environmental events causing type 1 diabetes influence thyroid autoimmunity. Methods Monozygotic and dizygotic twins discordant for type 1 diabetes from the UK and USA were tested for thyroid peroxidase autoantibodies (TPOA) by radioimmunoassay. Using quantitative genetic model fitting of a liability-threshold model we estimated the contribution of genetic (heritability) and environmental factors to TPOA. Results TPOA positivity was higher in females than in males in both cohorts and was associated with later age at diagnosis in the UK and combined cohorts (p<0.01). TPOA did not specifically segregate with type 1 diabetes in the twin pairs (p>0.2 in all groups). The best-fitting models showed heritability (95% CI) estimates for TPOA of 63% (37%, 80%) for the UK and 80% (51%, 92%) for US twins, while the best-fitting meta-analysis model of the two twin cohorts combined included additive genetic and unique environmental factors with a heritability estimate of 69% (50%, 82%). Conclusions/interpretation Risk of thyroid autoimmunity, defined by TPOA, in the context of autoimmune diabetes is, substantially, genetically determined in discordant twin pairs. Environmental factors leading to type 1 diabetes were not the same as those involved with thyroid autoimmunity. It follows that it is as important to investigate for thyroid autoimmunity in relatives of type 1 diabetes patients as it is in the patients themselves. PMID:26070305

  9. Sexual Behavior in Young Adulthood: A Population-Based Twin Study

    PubMed Central

    Mustanski, Brian; Viken, Richard J.; Kaprio, Jaakko; Winter, Torsten; Rose, Richard J.

    2007-01-01

    Objective With behavior genetic analyses of data from young adult twins, we evaluated theoretical perspectives that differentially emphasize biological dispositions, social/cultural factors, or universal pathways to explain individual differences in sexual behaviors. Design We fit biometric sex limitation models to three aspects of sexual behavior reported by 4,925 Finnish twins aged 23–27. The sample, from five consecutive birth cohorts, of 2,448 twin pairs (886 sister-sister, 862 brother-sister, 700 brother-brother), included 785 monozygotic and 801 same-sex dizygotic pairs. In addition to model fitting data from twin pairs, we conducted analyses on twins as individuals to test for independence of initiation of sexual behavior from onset age and number of partners. Main Outcome Measures From a postal questionnaire, we obtained self-report information on initiation/abstinence of sexual intercourse, onset age, and number of sexual partners. Results Genetic and non-shared environmental influences were significant for all three measures. There were trends for common environmental influences on initiation and, in females, age at first intercourse. Some differential effects in males and females were found. Results comparing onset age and number of partners among experienced twins from pairs concordant and discordant for initiation found genetic and environmental influences on initiation/abstinence overlapped those found for the other aspects of sexual behavior. Conclusions These results document genetic variation in individual differences in sexual behavior of young adults. Incorporating genetic dispositions into integrated models of sexual behavior will facilitate more effective health promotion and risk taking intervention. PMID:17845112

  10. Genetic and Environmental Influences on Traits of Gender Identity Disorder: A Study of Japanese Twins Across Developmental Stages.

    PubMed

    Sasaki, Shoko; Ozaki, Koken; Yamagata, Shinji; Takahashi, Yusuke; Shikishima, Chizuru; Kornacki, Tamara; Nonaka, Koichi; Ando, Juko

    2016-10-01

    The present study examined: (1) gender and age differences of mean gender identity disorder (GID) trait scores in Japanese twins; (2) the validity of the prenatal hormone transfer theory, which predicts that, in dizygotic (DZ) twin pairs, twins with an opposite-gender co-twin more frequently exhibit GID traits than twins with a same-gender co-twin; and (3) the magnitude of genetic and environmental influences on GID traits as a function of age and gender. Data from 1450 male twin pairs, 1882 female twin pairs, and 1022 DZ male-female pairs ranging from 3 to 26 years of age were analyzed. To quantify individual variances in GID traits, each participant completed four questionnaire items based on criteria for GID from the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). Our most important findings were: (1) Japanese females exhibited GID traits more frequently than males and Japanese children exhibited GID traits less frequently than adolescents and adults (among females, the prevalence was 1.6 % in children, 10 % in adolescents, and 12 % in adults; among males, the prevalence was 0.5, 2, and 3 %, respectively); (2) the data did not support the prenatal hormone transfer theory for GID traits; and (3) a large part of the variance for GID traits in children was accounted for by familial factors; however, the magnitude was found to be greater in children than in adolescents or adults, particularly among females. This study suggests that although the prevalence is likely to increase, familial effects are likely to decrease as individuals age. PMID:27507021

  11. Insights on Solar Twins

    NASA Astrophysics Data System (ADS)

    Sousa Duarte, Tharcisyo Sa e.; Soares da Costa, Jefferson; Dias do Nascimento Júnior, José

    2015-08-01

    The question about how to define a real solar twin are still active. Cayrel de Strobe et al. (1981) defined a solar twin like a star having at the same time the physical parameters, Teff, gravity, bolometric magnitude, microturbulent velocity, and chemical composition. We presented the more extensive sample of solar twins known to date. From these targets we will study the behavior of the solar twins as a function of fundamentals stellar parameters, effective temperature, luminosity, age, convective envelope mass deepening (1 - M*/M⊙), lithium abundance and rotation period. We selected the solar twins from observations with the spectropolarimeters ESPaDOnS at CFHT and the Narval at TBL and also on literature. All objects have high resolution and high signal to noise. Analyze this sample of solar twins will help us to understand how these stars whether located around of the Sun's place. Our preliminary results show that the lithium abundance presents one clear correlation with stellar age. The (1 - M*/M⊙) values obtained through our method provided good agreement with the solar value. The rotation periods allow us to assess the solar twins as a function of gyrochronology.

  12. An Investigation of Exceptional Twins.

    ERIC Educational Resources Information Center

    Crismore, Avon

    The author, herself a mother of twins, reviews research on exceptional twins. She considers reasons for fascination with twins and comments upon important advances in technology. Current research in Indianapolis to measure cognitive, perceptual, personality, and chromosome patterns of twins is described. Differences in the makeup of identical and…

  13. The use of DNA fingerprinting to assess monozygotic twinning in Meishan and Landrace x large white pigs.

    PubMed

    Ashworth, C J; Ross, A W; Barrett, P

    1998-01-01

    The extent of embryo mortality is usually estimated by the difference between the numbers of corpora lutea and embryos in the same animal, which assumes that each corpora lutea represents one potential embryo. Recent observations from the authors' laboratory reveal situations in which the number of embryos exceeds the number of corpora lutea, implicating the presence of identical twins. The objective of the present study was to establish DNA fingerprinting techniques to investigate the prevalence of monozygotic twinning in two breeds of pig. DNA fingerprints of every fetus carried by 6 Meishan (MS) and 6 Landrace x Large White (LxLW) gilts on Day 29 +/- 2 of pregnancy were obtained. Five LxLW and 3 MS litters carried no identical fetuses. The remaining gilts carried a pair of fetuses with indistinguishable DNA profiles. No pairs of fetuses were monochorionic. These results suggest that monozygotic twinning in the pig occurs during embryo cleavage or blastocyst development and may be more prevalent in MS compared with indigenous breeds. PMID:10588379

  14. Chudley-McCullough Syndrome: Variable Clinical Picture in Twins with a Novel GPSM2 Mutation.

    PubMed

    Koenigstein, Karsten; Gramsch, Carolin; Kolodziej, Malgorzata; Neubauer, Bernd A; Weber, Axel; Lechner, Sarah; Hahn, Andreas

    2016-06-01

    Chudley-McCullough syndrome (CMS) is a rare autosomal recessive disorder characterized by sensorineural deafness, agenesis of the corpus callosum, frontal polymicrogyria, interhemispheric cyst, and ventricular enlargement. CMS is caused by mutations in the GPSM2 gene, but until now no more than eight different mutations are on record. We describe two dizygotic twins with a novel homozygous loss-of-function mutation (c.1093C > T; p.Arg365*). While one child developed hydrocephalus-prompting shunt implantation immediately after birth, the other sibling did not. The combination of sensorineural hearing loss and partial agenesis of the corpus callosum is a highly recognizable clinico-radiological entity that should prompt mutational analysis of the GPSM2 gene. PMID:27064331

  15. LETTER TO THE EDITOR: Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion. Nonlinear decay of adult red blood cells

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; Pasman, Suzanne A.; van den Wijngaard, Jeroen P. H. M.; Lopriore, Enrico; Vandenbussche, Frank P. H. A.

    2008-07-01

    Recently, we derived equations relating the flow of adult red blood cells through a placental arterio-venous anastomosis with intra-uterine and post-natal measured adult hemoglobin concentrations. In this letter, we re-derived the equations, now including a more realistic nonlinear decay of adult red blood cells, and re-evaluated the measurement accuracy of the arterio-venous flow and the lifetime of the red blood cells.

  16. Genetic and Environmental Contributions to Behavioral Stability and Change in Children 6-36 months of Age Using Louisville Twin Study Data.

    PubMed

    Davis, Deborah Winders; Finkel, Deborah; Turkheimer, Eric; Dickens, William

    2015-11-01

    The Infant Behavior Record (IBR) from the Bayley Scales of Infant Development has been used to study behavioral development since the 1960s. Matheny (1983) examined behavioral development at 6, 12, 18, and 24 months from the Louisville Twin Study (LTS). The extracted temperament scales included Task Orientation, Affect-Extraversion, and Activity. He concluded that monozygotic twins were more similar than same-sex dizygotic twins on these dimensions. Since this seminal work was published, a larger LTS sample and more advanced analytical methods are available. In the current analyses, Choleksy decomposition was applied to behavioral data (n = 1231) from twins 6-36 months. Different patterns of genetic continuity vs genetic innovations were identified for each IBR scale. Single common genetic and shared environmental factors explained cross-age twin similarity in the Activity scale. Multiple shared environmental factors and a single genetic factor coming on line at age 18 months contributed to Affect-Extraversion. A single shared environmental factor and multiple genetic factors explained cross-age twin similarity in Task Orientation. PMID:26477572

  17. Preparing for Twins

    MedlinePlus

    ... single baby. Feeding twins, whether by breast or bottle, also requires some special strategies, and the doctor ... fertilization may involve implanting more than one fertilized egg into the uterus, while using infertility drugs can ...

  18. [Twin studies in psychiatry].

    PubMed

    Kringlen, E

    1999-09-20

    Twin research in medicine and psychology has blossomed during the last decades. A brief presentation of twin research methods is given, followed by a review of psychiatric studies, particularly Norwegian ones. The Nordic investigations are of great importance because many of these studies have been able to avoid shortcomings in sampling by linking national twin registers to disease registers. This procedure is of consequence for the estimation of heritability. Twin research shows that the genetic contribution to Alzheimer's disease, manic-depressive (bipolar) disorder, schizophrenia and childhood autism is relatively strong, whereas genetic factors play a minor role in common depressions, anxiety and somatoform disorders, and alcohol abuse. Since the concordance rates are far from 100 percent in most of these illnesses, environmental factors must also be important. PMID:10533417

  19. Genetic pleiotropy between asthma and obesity in a community-based sample of twins

    PubMed Central

    Hallstrand, Teal S.; Fischer, Mary E.; Wurfel, Mark M.; Afari, Niloofar; Buchwald, Dedra; Goldberg, Jack

    2007-01-01

    Background Asthma and obesity are common conditions that are strongly associated. This association might be due to shared genetic or environmental causes. Objective We sought to determine whether a shared genetic cause is responsible for the association between asthma and obesity and to estimate the magnitude of shared genetic cause. Methods The analyses were performed with 1001 monozygotic and 383 dizygotic same-sex twin pairs within the University of Washington Twin Registry. The presence of asthma was determined by self-report of a physician diagnosis of asthma, and body mass index (BMI) was calculated by using self-reported height and weight. Obesity was defined as a BMI of 30 or greater. The association between asthma and BMI was assessed by means of mixed-effects ordinal regression. Twin correlations examined the association of asthma and obesity. Univariate and bivariate structural equation models estimated the components of variance attributable to genetic and environmental effects. Results A strong association between asthma and BMI was identified in the sample population (P < .001). Substantial heritability was detected for asthma (53%) and obesity (77%), which is indicative of additive genetic influences on each disorder. The best-fitting model of shared components of variance indicated that 8% of the genetic component of obesity is shared with asthma. Conclusion The covariation between obesity and asthma is predominantly caused by shared genetic risk factors for both conditions. PMID:16337451

  20. Heritability of Pain Catastrophizing and Associations with Experimental Pain Outcomes: A Twin Study

    PubMed Central

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R.; Afari, Niloofar

    2014-01-01

    The current study employed a twin paradigm to examine the genetic and environmental contributions to pain catastrophizing as well as the observed association between pain catastrophizing and cold pressor task (CPT) outcomes. Male and female monozygotic (n=206) and dizygotic twins (n=194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold pressor immersion tolerance, pain tolerance, and delayed pain rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, suggesting a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response. PMID:25599234

  1. Common Etiological Sources of Anxiety, Depression, and Somatic Complaints in Adolescents: A Multiple Rater twin Study.

    PubMed

    Ask, Helga; Waaktaar, Trine; Seglem, Karoline Brobakke; Torgersen, Svenn

    2016-01-01

    Somatic complaints in children and adolescents may be considered part of a broader spectrum of internalizing disorders that include anxiety and depression. Previous research on the topic has focused mainly on the relationship between anxiety and depression without investigating how common somatic symptoms relate to an underlying factor and its etiology. Based on the classical twin design with monozygotic and dizygotic twins reared together, our study aimed to explore the extent to which the covariation between three phenotypes in adolescent girls and boys can be represented by a latent internalizing factor, with a focus on both common and specific etiological sources. A population-based sample of twins aged 12-18 years and their mothers and fathers (N = 1394 families) responded to questionnaire items measuring the three phenotypes. Informants' ratings were collapsed using full information maximum likelihood estimated factor scores. Multivariate genetic analyses were conducted to examine the etiological structure of concurrent symptoms. The best fitting model was an ACE common pathway model without sex limitation and with one substantially heritable (44%) latent factor shared by the phenotypes. Concurrent symptoms also resulted from shared (25%) and non-shared (31%) environments. The factor loaded most on depression symptoms and least on somatic complaints. Trait-specific influences explained 44% of depression variance, 59% of anxiety variance, and 65% of somatic variance. Our results suggest the presence of a general internalizing factor along which somatic complaints and mental distress can be modeled. However, specific influences make the symptom types distinguishable. PMID:25619928

  2. Environmental Factors Responsible for Variability of Hepatic Vein Flow: A Doppler Assessment in Healthy Twins.

    PubMed

    Tarnoki, Adam D; Tarnoki, David L; Littvay, Levente; Garami, Zsolt; Molnar, Andrea Agnes; Berczi, Viktor; Karlinger, Kinga; Baffy, Gyorgy

    2016-02-29

    Doppler interrogation studies of the liver blood flow indicate altered hepatic vein waveforms in association with impaired hepatocellular function. However, little is known about the mechanisms responsible for variations of these parameters in the absence of disease. We aimed to investigate the contribution of heritable and environmental factors to the physiological variability of hepatic vein flow in a twin cohort. Two hundred twenty-eight healthy adult Hungarian twins (69 monozygotic, 45 same-sex dizygotic pairs) underwent Doppler sonography of the hepatic vein. Age- and sex-adjusted heritability of the highest velocity (amplitude of S wave) of hepatic vein flow was negligible. Shared environment contributed to 33% (95% CI, 16%-51%), and unshared environment was responsible for the largest portion (67%; 95% CI, 49%-84%) of the variance. Duration of sports activities was significantly (P < 0.05) related to the magnitude of hepatic vein flow, while other risk factors and lifestyle characteristics had no significant influence. The data suggest that genetic factors have little impact on the parameters of hepatic venous blood flow. The variability observed in healthy twins by the Doppler interrogation can be explained by the effect of unshared environmental components primarily related to regular physical activity. These findings underscore the importance of unique environments in physiological variations of hepatic venous blood flow. PMID:26875560

  3. Epigenetic Variation in Monozygotic Twins: A Genome-Wide Analysis of DNA Methylation in Buccal Cells

    PubMed Central

    van Dongen, Jenny; Ehli, Erik A.; Slieker, Roderick C.; Bartels, Meike; Weber, Zachary M.; Davies, Gareth E.; Slagboom, P. Eline; Heijmans, Bastiaan T.; Boomsma, Dorret I.

    2014-01-01

    DNA methylation is one of the most extensively studied epigenetic marks in humans. Yet, it is largely unknown what causes variation in DNA methylation between individuals. The comparison of DNA methylation profiles of monozygotic (MZ) twins offers a unique experimental design to examine the extent to which such variation is related to individual-specific environmental influences and stochastic events or to familial factors (DNA sequence and shared environment). We measured genome-wide DNA methylation in buccal samples from ten MZ pairs (age 8–19) using the Illumina 450k array and examined twin correlations for methylation level at 420,921 CpGs after QC. After selecting CpGs showing the most variation in the methylation level between subjects, the mean genome-wide correlation (rho) was 0.54. The correlation was higher, on average, for CpGs within CpG islands (CGIs), compared to CGI shores, shelves and non-CGI regions, particularly at hypomethylated CpGs. This finding suggests that individual-specific environmental and stochastic influences account for more variation in DNA methylation in CpG-poor regions. Our findings also indicate that it is worthwhile to examine heritable and shared environmental influences on buccal DNA methylation in larger studies that also include dizygotic twins. PMID:24802513

  4. Epigenetic variation in monozygotic twins: a genome-wide analysis of DNA methylation in buccal cells.

    PubMed

    van Dongen, Jenny; Ehli, Erik A; Slieker, Roderick C; Bartels, Meike; Weber, Zachary M; Davies, Gareth E; Slagboom, P Eline; Heijmans, Bastiaan T; Boomsma, Dorret I

    2014-01-01

    DNA methylation is one of the most extensively studied epigenetic marks in humans. Yet, it is largely unknown what causes variation in DNA methylation between individuals. The comparison of DNA methylation profiles of monozygotic (MZ) twins offers a unique experimental design to examine the extent to which such variation is related to individual-specific environmental influences and stochastic events or to familial factors (DNA sequence and shared environment). We measured genome-wide DNA methylation in buccal samples from ten MZ pairs (age 8-19) using the Illumina 450k array and examined twin correlations for methylation level at 420,921 CpGs after QC. After selecting CpGs showing the most variation in the methylation level between subjects, the mean genome-wide correlation (rho) was 0.54. The correlation was higher, on average, for CpGs within CpG islands (CGIs), compared to CGI shores, shelves and non-CGI regions, particularly at hypomethylated CpGs. This finding suggests that individual-specific environmental and stochastic influences account for more variation in DNA methylation in CpG-poor regions. Our findings also indicate that it is worthwhile to examine heritable and shared environmental influences on buccal DNA methylation in larger studies that also include dizygotic twins. PMID:24802513

  5. Causes and consequences of obesity: the contribution of recent twin studies.

    PubMed

    Naukkarinen, J; Rissanen, A; Kaprio, J; Pietiläinen, K H

    2012-08-01

    Obesity is a genetically complex disorder that produces a myriad of health problems. Most of the recognized complications of obesity are not only strongly influenced by lifestyle factors, but also present with independent genetic predispositions that are notoriously difficult to disentangle in humans. Most studies on the causes and consequences of acquired obesity are encumbered by the incomplete ability to control for genetic influences. However, utilizing a unique experiment of nature, namely monozygotic twins (MZ) discordant for obesity as 'clonal controls' of obese and non-obese individuals has enabled the fine characterization of the effects and possible antecedents of acquired obesity while controlling for the genetic background, as well as pointed to novel obesity predisposing candidate genes. This review is a distillation of the findings from more than 10 years of research done in an exceptionally well-characterized collection of MZ and dizygotic (DZ) twins, based on the Finnish Twin Cohorts. Topics covered include the nature of development of obesity from the childhood onwards, the role of exercise in modifying the genetic susceptibility, the resulting inflammatory, prediabetic and preatherosclerotic changes in whole body and adipose tissue physiology, as well as the newest insights provided by the omics revolution. PMID:21986704

  6. Adult monozygotic twins discordant for intra-uterine growth have indistinguishable genome-wide DNA methylation profiles

    PubMed Central

    2013-01-01

    Background Low birth weight is associated with an increased adult metabolic disease risk. It is widely discussed that poor intra-uterine conditions could induce long-lasting epigenetic modifications, leading to systemic changes in regulation of metabolic genes. To address this, we acquire genome-wide DNA methylation profiles from saliva DNA in a unique cohort of 17 monozygotic monochorionic female twins very discordant for birth weight. We examine if adverse prenatal growth conditions experienced by the smaller co-twins lead to long-lasting DNA methylation changes. Results Overall, co-twins show very similar genome-wide DNA methylation profiles. Since observed differences are almost exclusively caused by variable cellular composition, an original marker-based adjustment strategy was developed to eliminate such variation at affected CpGs. Among adjusted and unchanged CpGs 3,153 are differentially methylated between the heavy and light co-twins at nominal significance, of which 45 show sensible absolute mean β-value differences. Deep bisulfite sequencing of eight such loci reveals that differences remain in the range of technical variation, arguing against a reproducible biological effect. Analysis of methylation in repetitive elements using methylation-dependent primer extension assays also indicates no significant intra-pair differences. Conclusions Severe intra-uterine growth differences observed within these monozygotic twins are not associated with long-lasting DNA methylation differences in cells composing saliva, detectable with up-to-date technologies. Additionally, our results indicate that uneven cell type composition can lead to spurious results and should be addressed in epigenomic studies. PMID:23706164

  7. Evolutionary genetics and implications of small size and twinning in callitrichine primates

    PubMed Central

    Harris, R. Alan; Tardif, Suzette D.; Vinar, Tomas; Wildman, Derek E.; Rutherford, Julienne N.; Rogers, Jeffrey; Worley, Kim C.; Aagaard, Kjersti M.

    2014-01-01

    New World monkeys (NWMs) are characterized by an extensive size range, with clawed NWMs (subfamily Callitrichinae, or callitrichines) such as the common marmoset manifesting diminutive size and unique reproductive adaptations. Perhaps the most notable of these adaptations is their propensity toward multiple gestations (i.e., dichorionic twins and trichorionic triplets). Indeed, with the exception of Goeldi’s monkey (Callimico), callitrichine singleton pregnancies rarely occur. Multiple gestations seem to have coevolved with a suite of reproductive adaptations, including hematopoetic chimerism of siblings, suppression of reproduction in nondominant females, and cooperative alloparenting. The sequencing of the common marmoset (Callithrix jacchus) genome offers the opportunity to explore the genetic basis of these unusual traits within this primate lineage. In this study, we hypothesized that genetic changes arising during callitrichine evolution resulted in multiple ovulated ova with each cycle, and that these changes triggered adaptations that minimized complications common to multiple gestations in other primates, including humans. Callitrichine-specific nonsynonymous substitutions were identified in GDF9, BMP15, BMP4, and WFIKKN1. WFIKKN1, a multidomain protease inhibitor that binds growth factors and bone morphogenetic proteins, has nonsynonymous changes found exclusively in common marmosets and other tested callitrichine species that twin. In the one callitrichine species that does not produce twins (Callimico), this change has reverted back to the ancestral (nontwinning) primate sequence. Polymorphisms in GDF9 occur among human cohorts with a propensity for dizygotic twins, and polymorphisms in GDF9 and BMP15 are associated with twinning in sheep. We postulate that positive selection affected NWM growth patterns, with callitrichine miniaturization coevolving with a series of reproductive adaptations. PMID:24379383

  8. Evolutionary genetics and implications of small size and twinning in callitrichine primates.

    PubMed

    Harris, R Alan; Tardif, Suzette D; Vinar, Tomas; Wildman, Derek E; Rutherford, Julienne N; Rogers, Jeffrey; Worley, Kim C; Aagaard, Kjersti M

    2014-01-28

    New World monkeys (NWMs) are characterized by an extensive size range, with clawed NWMs (subfamily Callitrichinae, or callitrichines) such as the common marmoset manifesting diminutive size and unique reproductive adaptations. Perhaps the most notable of these adaptations is their propensity toward multiple gestations (i.e., dichorionic twins and trichorionic triplets). Indeed, with the exception of Goeldi's monkey (Callimico), callitrichine singleton pregnancies rarely occur. Multiple gestations seem to have coevolved with a suite of reproductive adaptations, including hematopoetic chimerism of siblings, suppression of reproduction in nondominant females, and cooperative alloparenting. The sequencing of the common marmoset (Callithrix jacchus) genome offers the opportunity to explore the genetic basis of these unusual traits within this primate lineage. In this study, we hypothesized that genetic changes arising during callitrichine evolution resulted in multiple ovulated ova with each cycle, and that these changes triggered adaptations that minimized complications common to multiple gestations in other primates, including humans. Callitrichine-specific nonsynonymous substitutions were identified in GDF9, BMP15, BMP4, and WFIKKN1. WFIKKN1, a multidomain protease inhibitor that binds growth factors and bone morphogenetic proteins, has nonsynonymous changes found exclusively in common marmosets and other tested callitrichine species that twin. In the one callitrichine species that does not produce twins (Callimico), this change has reverted back to the ancestral (nontwinning) primate sequence. Polymorphisms in GDF9 occur among human cohorts with a propensity for dizygotic twins, and polymorphisms in GDF9 and BMP15 are associated with twinning in sheep. We postulate that positive selection affected NWM growth patterns, with callitrichine miniaturization coevolving with a series of reproductive adaptations. PMID:24379383

  9. Path analytic, sib-pair linkage and co-twin control studies of asthma and atopy

    SciTech Connect

    Duffy, D.L.; Healey, S.C.; Martin, N.G.

    1994-09-01

    Asthma and atopy are complex traits with multifactorial determinants, and require appropriate choice of phenotypes and analyses, including a linkage analysis of the putative 11q atopy locus. Participants in a large registry-based twin study of asthma were invited to take part in clinical testing. A total of 863 individuals including 419 complete twin pairs (where one or both members reported a history of wheeze) underwent histamine inhalation challenge, allergen skin prick testing, and venesection. Total serum immunoglobulin E (IgE) and bronchial responsiveness (BR) to histamine were highest in those who had wheezed most recently, and whose skin tests demonstrated allergy to house dust mite, cockroach, and rye grass. In ascertainment-corrected path analyses (FISHER), the heritability of IgE and BR were both 60%. Monozygotic (MZ) co-twin control analyses suggested house dust mite sensitization was the single strongest environmentally controlled risk factor for wheeze, while path analyses suggested genetic determination. In dizygotic (DZ) co-twin control analyses, sensitization to grasses was also an important predictor, suggesting pollinosis to be genetically correlated with wheezing, rather than causative. Multivariate path analyses suggested separate (correlated) genetic factors for BR, IgE, and allergy to house dust mite. A sib-pair (Haseman-Elston) linkage analysis of 220 DZ twin pairs did not support linkage to the high-affinity IgE receptor beta-subunit gene on 11q13 of atopy or BR. More recent linkage analyses that include parental genotyping will also be discussed. We conclude that the atopic phenotype consists of a number of traits with specific genetic allergens. Exposure to particular allergens can then cause specific outcomes, such as asthma.

  10. Association between major depression and type 2 diabetes in mid-life: Findings from the Screening Across the Lifespan Twin Study

    PubMed Central

    Mezuk, Briana; Heh, Victor; Prom-Wormley, Elizabeth; Kendler, Kenneth S.; Pedersen, Nancy L.

    2015-01-01

    Objective Cohort studies suggest that the relationship between major depression (MD) and type 2 diabetes (T2DM) is bi-directional. However, this association may be confounded by shared genetic or environmental factors. The objective of this study was to use a twin design to investigate the association between MD andT2DM. Methods Data come from the Screening Across the Lifespan Twin Study, a sample of monozygotic and dizygotic twins aged ≥40 sampled from the Swedish Twin Registry (N=37,043). MD was assessed using the Composite International Diagnostic Inventory. Structural equation twin modeling and Cox proportional hazards modeling were used to assess the relationship between MD and T2DM. Results Approximately 19% of respondents had a history of MD and 5% had a history of T2DM. MD was associated with 32% increased likelihood of T2DM (95% Confidence Interval: 1.00 – 1.80) among twins aged 40 – 55 even after accounting for genetic risk, but was not associated with T2DM among twins >55 years. T2DM was associated with 33% increased likelihood of MD (95% CI: 1.02 – 1.72) among younger, but not older twins. Cholesky decomposition twin modeling indicated that common unique environmental factors contribute to the association between MD and T2DM. Conclusions Environmental factors that are unique to individuals (e.g., not shared within families), but common to both MD and T2DM contribute to their co-occurrence in mid-life. However, we cannot exclude the possibility of bi-directional causation as an alternate explanation. It is likely that multiple processes are operating to affect the relation between psychological and medical conditions in mid-life. PMID:25967355