A brother and a sister presented with a malformation syndrome consisting of facial anomalies, distal arthrogryposis with camptodactyly of fingers and "hammer toes," severe mental retardation, and hypopituitarism. The girl is now 6 1/2 years old and exhibits severe mental retardation. She has abnormal secretion of growth hormone and responded to growth hormone therapy. Her brother was born with the same facial manifestations, distal contractures, and hypopituitarism. He died unexpectedly at age 3 months of no apparent cause. The occurrence of the syndrome in 2 sibs of different sex suggests autosomal recessive inheritance.