Zimmermann-Laband syndrome in a patient with severe mental retardation: The Zimmermann-Laband syndrome (ZLS) is a rare autosomal dominant disorder characterized by gingival hyperplasia or fibromatosis, various skeletal anomalies including dysplasia of the distal phalanges of thumbs and halluces, vertebral defects, and hepatosplenomegaly. Thus far, 23 cases, including 11 patients from 2 families, have been reported. Most cases of ZLS have a normal intelligence although some cases are mildly retarded. Differential diagnosis includes other causes of gingival hyperplasia. We report on a patient with ZLS and severe mental retardation and review the literature. We conclude that severe mental retardation is a feature of the syndrome.