TRISOMY-18 MOSAICISM IN A MILDLY RETARDED BOY WITH POSTNATAL OVERGROWTH

We report a 6-year-old mildly retarded boy with trisomy 18 in 44% of p eripheral lymphocytes. He had mild nonspecific dysmorphic features, mi crocephaly, micropenis with cryptorchidism and postnatal overgrowth, T risomy 18 mosaicism was confirmed by a fluorescent in situ hybridizati on study, Ten previous reports of trisomy 18 mosaicism with normal or subnormal intelligence have been described but only one case of trisom y 18 mosaicism with high stature has been reported.