On the basis of two recently studied human fetuses and the historical records and remnant 19th century skeletons in the Museum Vrolik in Amsterdam, we have begun an analysis of an unusual form of somite dysgenesis. This disorder includes vertebral and costal segmentation defects with or without (distal) limb malformation and deformities, anogenital anomalies, unusual colonic atresia, abdominal wall and diaphragmatic defect, Central nervous system abnormality with large head, and severe neurohypotrophic lower limb deformities. This study suggests the existence of an axial vertebral/costal dysgenesis complex with apparently or nearly normal number of cervical vertebrae. There also is some overlap with lumbosacral agenesis but different from the autosomal recessive entities Jarcho-Levin syndrome or spondylocostal dysostosis. To date, no associated heart defects have been noted.