Trisomy 8 mosaicism. A case report and a proposed list of the clinical features.

A 16-year-old boy with trisomy 8 mosaicism is presented. Increased birth weight, delayed psychomotoric and accelerated somatic development, and mental retardation were noted; he exhibited a prominent forehead, a broad-bridged upturned nose, an everted lower lip, low set dysmorphic ears, strabismus, slender trunk, narrow pelvis, osseous and joint anomalies, clinodactyly, deep skin furrows on the soles, and agenesis of the corpus callosum. The trisomic cell line was observed throughout the follow-up examinations from the fibroblast cultures between 1962 and 1973, but has disappeared from the lymphocyte culture. The clinical picture of this case is compared with the leading clinical signs and symptoms of the 25 cases with confirmed trisomy 8 so far published. A scheme is proposed in order to keep in mind the clinical picture suggesting trisomy 8.