Ring chromosome 17 in a mentally retarded boy.

A six-year-old boy was found to have a ring chromosome 17. In addition to psychomotor retardation, speech delay and seizure disorders, his abnormal phenotypic features included epicanthal folds, broad depressed nasal bridge, protruding thick upper and lower lips, micrognathia, narrow high arched palate, short fifth fingers with a mild degree of clinicodactyly, multiple café-aui-lait spots, and abnormal dermatoglyphics.