Caudal regression syndrome

Caudal regression syndrome
Other names	Sacral regression sequence, Sacral agenesis
Sacral agenesis
Specialty	Medical genetics

Caudal regression syndrome, or sacral agenesis (or hypoplasia of the sacrum), is a rare birth defect. It is a congenital disorder in which the fetal development of the lower spine—the caudal partition of the spine—is abnormal.^[1] It occurs at a rate of approximately one per 60,000 live births.^[2]

Some babies are born with very small differences compared to typical development, and others have significant changes. Most grow up to be otherwise typical adults who have difficulty with walking and incontinence.