Monochorionic‐diamniotic twins discordant in gender from a naturally conceived pregnancy through postzygotic sex chromosome loss in a 47,XXY zygote

Abstract excerpt

OBJECTIVE: It is generally believed that monochorionic-diamniotic twin pregnancies result from one fertilized oocyte with both siblings having the same genotype and phenotype. In rare instances, due to somatic mutations or chromosome aberrations, the karyotypes and phenotypes of the two twins can differ. METHOD: We report cytogenetic, molecular genetic and clinical examinations in monochorionic-diamniotic twins...