Hypomelanosis of Ito associated with mosaicism for trisomy 7 and apparent 'pseudomosaicism' at amniocentesis.

Abstract

We describe a patient with hypomelanosis of Ito (HI) and typical characteristics. Cytogenetic analysis of fibroblast cultures showed mosaicism for trisomy 7. The trisomy cell line was first observed in an amniotic fluid culture and illustrates the problem of distinguishing pseudomosaicism from true mosaicism.