De novo tandem duplication of the middle segment of the long arm of chromosome 14.

A boy with a peculiar face and slight psychomotor retardation was found to have a tandem duplication of segment 14q13-22. The karyotype was described as 46,XY, dir dup (14)(pter-q22::q13-q22::q22-qter), being trisomic for the segment. His parents were normal both phenotypically and cytogenetically. The clinical features of the propositus were compared with those of previously reported cases of trisomy 14q involving segment 14q13-22.