• developmental field;
  • axial mesodermal defect;
  • caudal “regression,”;
  • female pseudohermaphroditism;
  • genital hypertrophy


We have studied two newborn infants with a remarkable genital malformation, failure of urethral development with enormous bladder distension, atresia of the distal hindgut, vertebral abnormalities, and compression deformities. This is a pattern of anomalies similar to, and probably an extension of, the association of female pseudohermaphroditism and other anomalies (FPA) described by Lubinsky [Am J Med Genet 6:123–136, 1980]. We propose that its pathogenesis involves a defect expressed in mesoderm, especially caudal mesoderm. We offer some speculation on what might be its nature, with particular reference to the theory of cell surface molecules having a role in morphogenesis. We apply the concept of the developmental field to provide a clarifying perspective.