Occipital horn syndrome: report of a patient and review of the literature.

We report an 18-year-old boy with occipital horn syndrome and we review the 20 cases previously published with this syndrome. The distinctive features common to all patients were unusual facial appearance, skeletal abnormalities, chronic diarrhea and genitourinary abnormalities. The skeletal abnormalities included occipital horns, short, broad clavicles, deformed radii, ulnae, and humeri, narrowing of the rib cage, undercalcified long bones with thin cortical walls and coxa valga. Occipital horn syndrome is inherited in an X-linked recessive fashion. Our analysis indicates that occipital horn syndrome is associated with a recognizable characteristic phenotype.