Blaschkolinear malformation syndrome in complex trisomy-7 mosaicism

Results of repeated peripheral blood chromosome studies were normal in a bo y with intrauterine growth retardation, short stature, moderate mental reta rdation, and multiple minor anomalies. At age 9 years it was recognized tha t the swirls of pigmentation/depigmentation on his trunk, linear streaks on his limbs, and body asymmetry were suggestive of chromosomal mosaicism, Fo ur skin biopsies were obtained under anesthesia during a dental procedure, All showed mosaicism for a normal cell line, a line with an extra chromosom e 7, and a cell line with an extra small ring. In one biopsy, there was a f ourth cell line with an extra chromosome 7 and the ring, Fluorescence in si tu hybridization (FISH) with a chromosome 7 paint confirmed trisomy 7 and t he chromosome 7 derivation of the ring. This young man's intra-uterine and postnatal growth retardation is an aneuploidy effect, whereas his asymmetry reflects a mosaicism effect that should have aroused suspicion of tissue-l imited mosaicism before the development of obvious Blaschkolinear skin pigm entary dysplasia, Am. J. Med. Genet. 87:375-383, 1999. (C) 1999 Wiley-Liss, Inc.