This female
dizygotic twin (birth weight 1 910 g) was delivered by caesarian section at 34 weeks' gestation for premature rupture of membranes.
Though prevalence of DS among twin gestations is lower compared to singletons, there is a higher relative risk of diagnosing at least one twin in
dizygotic twin pregnancies with DS compared to singleton pregnancies and monozygotic twin pregnancies [2].
Data Source: A population-based twin study involving 54 monozygotic and 138
dizygotic twin pairs born in 1987-2004 in which at least one of the twins met the diagnostic criteria for autism or autism spectrum disorder.
With time it became clear that this second sculpture court was in fact laid out as a mirror image of the first; each sculpture in the first room had a
dizygotic twin in the second that had been placed in a bilaterally symmetrical relation to the implied seam bisecting the gallery.
While both genetics and environment have a role to play in the relationship between height and cognition, environmental factors appear to be responsible for two-thirds of the height-intelligence correlation, according to research conducted on cross-trait (height and intelligence), cross-twin correlations between monozygotic and
dizygotic twin pairs.
The risk is greater in
dizygotic twin gestations than in age-matched singleton gestations.
In contrast, no concordance for autism was noted in
dizygotic twin pairs and only 10% were concordant for some form of cognitive, social, or language deficit.
Data were collected from monozygotic and
dizygotic twin pair members of the Vietnam Era Twin (VET) Registry who responded to the VA's Survey of Health in 1987.
Large fluctuations were expected for
dizygotic twin pregnancies, because the informative SNP loci would consist of 2 categories, loci in which both fetuses were heterozygous (1) and loci in which only one of the twins was heterozygous (2) (Fig.
In a separate study of 98 mono- and
dizygotic twin pairs conducted by Jonas Halfvarson, M.D., of Orebro (Sweden) University Hospital and his associates, ASCA were found in only 1 of 20 healthy twin siblings in monozygotic twin pairs that were discordant for Crohn's disease compared with 7 of 27 healthy twin siblings in discordant dizygotic pairs.
A separate study of 98 mono- and
dizygotic twin pairs conducted by Jonas Halfvarson, M.D., of Orebro University Hospital (Sweden) and his associates found that ASCA were found in only 1 of 20 healthy twin siblings in monozygotic twin pairs that were discordant for Crohn's disease, compared with 7 of 27 healthy twin siblings in discordant dizygotic pairs.
The sequential cohort study included data from 749 monozygotic twin pairs and 687
dizygotic twin pairs between the age of 8 and 17 and their parents.