Eight patients in three families had mental retardation, characteristic facies and hands, and skeletal changes; the clinical features suggested to us that they had a syndrome previously thought to represent two entities described by Lowry and associates and by Coffin and associates, respectively. New findings include skeletal, orodental, and dermatoglyphic abnormalities and histopathologic changes suggesting that the syndrome is a heritable disorder of connective tissue. Severe expression in males and transmission through mildly affected females suggest X-linked or sex-influenced autosomal dominant inheritance.