The sturdiness of genetic factors is marked by the rise of lifetime risk of the disease from just below 1% in general population to over 40% in monozygotic twin
studies, leading to author--Hong's extensive searches for the genetic basis of the disease.
A heteropagus conjoined twin is not viable because it is a partially formed parasitic monozygotic twin
, asymmetrically attached, and completely dependent for survival on the viable and dominant twin, termed as the autosite.
* A monozygotic twin
pair (one of whom was a patient of mine) born to a mother with bipolar disorder and adopted at birth by different families developed bipolar disorder due to genetic transmission, but eventually had very different outcomes.
Epigenetic influences such as increased methylation on dopamine receptor D2 (DRD2) gene in normal individuals has also been proposed which is not found in monozygotic twin
Interestingly, there is a lower risk of DS in monozygotic twin
gestations relative to singleton pregnancies [2, 5], but an increased risk (~1/3-fold) of at least one twin being affected in dizygotic pregnancies .
Triplet (one monozygotic twin
and one singleton) was found by ultrasound test at 35 days after transfer, and ultrasound-guided selective pregnancy reduction for monozygotic twin
These results indicate that the monozygotic twin
rugae patterns are not identical with each other and their differences are greater than individual changes seen in the reference group over time [10, 11].
36 monozygotic twin
pairs entered the study: 6 concordant pairs (N = 12 for the concordant affected group) with both twins affected by schizophrenia/schizoaffective disorder, 11 discordant pairs where only one twin was affected by schizophrenia/schizoaffective disorder (therefore, N = 11 for each of the affected and unaffected discordant groups), and 19 concordant control pairs (N = 38 for the concordant healthy group) where both twins were psychiatrically healthy.
Genetic, environmental and stochastic factors in monozygotic twin
discordance with a focus on epigenetic differences.
In 16 of the 27 monozygotic twin
pairs participating in the study, one member of the pair had been exposed to cytomegalovirus but the other had not.
Twin studies have shown that monozygotic twin
sisters are frequently, if not always, discordant with respect to preeclampsia and/or HELLP.
Kawasaki disease associated with measles virus infection in a monozygotic twin
. Pediatr Infect Dis J.