Four boys of the same family (three first cousins and their uncle) had the same syndrome of multiple malformations. They had hypertelorism, antimongolian slant of the palpebral fissures, low-set ears, and Pierre Robin syndrome. The ossification of the skull vault was defective, with broad sutures and fontanelles. The ribs were sinuous, the clavicles were long, thin, and sloping, and the vertebrae were flattened. There were abnormal bowing with hyperostosis of the long bones, faulty ossification of the bones of hand and feet, and "fanned-out" toes. The disorder was lethal within a few weeks. The karyotype was normal. The mothers of affected boys had a mild form of the same abnormal facies. Transmission of this disorder appears to be linked to the X chromosome.