45,X/46,XX mosaicism in discordant monozygotic twins
Uchida, I.A.; deSa, D.J.; Whelan, D.T.
Pediatrics 71(3): 413-417
1983
ISSN/ISBN: 0031-4005 PMID: 6572357 Document Number: 215717
Monozygotic twins discordant for Turner's syndrome were both mosaic for 45,X/46,XX in the blood with the same low frequency of 2% to 3% 45,X cells. However, the fibroblasts of the abnormal girl were all uniformly 45,X whereas her normal twin had only 46,XX cells. Monozygosity was confirmed by genetic markers, chromosome variants, and a single monochorionic placenta with a shared vascular circulation. The mechanism by which this disparate pair developed from a single zygote is suggested.