Caudal regression syndrome

Caudal regression syndrome, also called sacral agenesis or hypoplasia of the sacrum, is a rare congenital disorder in which the fetal development of the lower part of the spine, the caudal portion, is abnormal. It occurs at a rate of roughly one in 60,000 live births. The severity varies widely, with some babies born with only minor differences from typical development while others have significant changes. Most grow up to be otherwise typical adults who have difficulty walking and incontinence.