The Dyggve-Melchior-Clausen syndrome is an inherited disorder of skeletal development characterized by short-trunked dwarfism, mental retardation, and a distinctive pattern of bone changes. The radiographic features seen in the 15 patients described in this report include platyspondyly with notched end plates of the vertebral bodies, small ilia with broad, frequently lacy crests, lateral displacement of the capital femoral epiphyses, and accessory ossification centers of the first metacarpals, proximal and middle phalanges. Cytological and biochemical data, notably a normal sulfate incorporation into acid mucopolysaccharides of cultured fibroblasts, indicate that the Dyggve-Melchior-Clausen syndrome is not a mucopolysaccharidosis as has been previously suggested.