Three families are presented in which four children have mesomelic brachymelia, hemivertebrae, short digits, and genital hypoplasia along with peculiar facies characterized by a flat profile, mild ocular hypertelorism, a short, broad upturned nose, and a small midline cleft in the lower lip. This condition should be suspected in any newborn male who has no visible penis or a micropenis. The children had normal birth weights and normal results for endocrine, biochemical, and chromosome studies. Available evidence suggests that the condition is heritable, but the mode of transmission is not clear. In view of the complex vertebral, extremity, and genital changes, the defective gene probably exerts its effect between the 8th and 12th weeks of gestation.