Zygodactyly as the most striking physical anomaly in an adult male patientwith pure partial trisomy 1q.

We report on a dysmorphic and mentally retarded adult male patient with par tial trisomy Iq resulting from a "de novo" tandem duplication of the 1q32.3 -->q42 region. The dysmorphic features consisted of facial asymmetry, synop hrys, right external strabismus, teeth anomalies and bilateral syndactyly o f fingers III-IV and toes II-III evoking zygodactyly. Clinical comparison i s made between the present observation and previously reported cases with p ure duplication including the chromosome 1 segment (q32-->q42).