BACKGROUND DNA methylation differences between monozygotic twins discordant for schizophrenia have been previously reported. However, the origin of methylation differences between monozygotic twins discordant for schizophrenia is not clear. The findings here argue that all DNA methylation differences may not necessarily represent the cause of the disease; rather some may result from the effect ...

Cases of congenital ptosis are rare, that too occurring in twins. We presenting a case mono zygotic twins with bilateral fibrosis extraocular muscles (CFEOM). A 5-year-old boy child and his twin brother who monozygotic presented ptosis. Both children had been diagnosed as having Parents have refused surgical intervention for the muscle weakness. They were advised, if complained any visual abnor...

In the present report, a case of 19 year-old monozygotic twin brothers with similar tooth agenesis and impacted primary teeth is presented. Both twins (HDH, DHH) had agenesis of ten and eleven teeth (respectively), third molars excluded, consistent with oligodontia and both had four impacted primary teeth and the permanent successors of all these primary teeth were congenitally missing. The occ...

We applied multivariate genetics techniques to a sample of 3,412 monozygotic and dizygotic twins from the United Kingdom and 1,300 monozygotic and dizygotic twins from the United States to examine whether genetic factors account for part of the covariance between the Big Five personality characteristics and the tendency to be an entrepreneur. We found that common genes influenced the phenotypic...

It is estimated that around 30% of all malignancies are caused by a “high-risk” genetic predisposition [1]. This estimation is based on an evaluation of occurrence of disease among monozygotic twins. If one of them is affected with prostate (PC) or breast cancer (BC), then the probability of occurrence of this disease in the second sibling is 40% for PC and 30% for BC [2]. The concordance among...

We previously described a co-twin control design using questionnaire data on monozygotic twins discordant and concordant for developmental coordination disorder (DCD) and attention deficit hyperactivity disorder (ADHD). Our results suggested that DCD and developmental ADHD had different causal pathways, and that second-born twins were at higher risk for oxygen perfusion problems than first-born...

The familial occurrence of systemic lupus erythematosus (SLE) is well established (Brunjes, Zike, and Julian, 1961; Leonhardt, 1964), and even monozygotic twins with this disease have been reported by several workers (Davis and Gutridge, 1951; Wagenhals and Burgeson, 1958; Blumenfeld, Kaplan, Mills, and Clark, 1963; Joseph and Zarafonetis, 1965; Lieberman, Heuser, Hanson, Kornreich, Donnell, an...

To date ten sets of monozygotic twins with neuroblastoma have been reported in the literature. Twin-to-twin in utero metastasis have been proposed as the mechanism of tumor development in the second twin; based on similar pathology, presence of metastatic disease, absence of a primary tumor, and/or later presentation in the second twin. Hereditary neuroblastoma has not been described in this co...

We investigated whether conception soon after cessation of use of oral contraceptives affects the chance of bearing twins. Unpublished data from a large sample survey of contraceptive practice in Scotland were used to derive oral contraceptive discontinuation rates by month over the decade 1972-82 and these were related to estimated monozygotic and dizygotic twin birth rates and proportions by ...