Extreme hypotrophy of the lower body pole, extensive hypoplasia of the spinal column and multiple anomalies of abdominal organs: a maximal variant of the caudal regression sequence?

A newborn with extreme hypotrophy of the lower body pole and aplasia of the lower spinal column is reported. Additional anomalies of internal organs included absence of one kidney and ureter, a diaphragmatic hernia, and anal atresia. Part of the organs located in the lower body pole were necrotic. There were no excretory apertures, and external genitalia were absent. Chromosomal analysis revealed a 46,XY karyotype. The multiple anomalies seen in this newborn may be interpreted as a maximal variant of the caudal regression sequence.