Urorectal septum malformation sequence. Report of six cases and embryological analysis
L. F. Escobar, D. D. Weaver, D. Bixler, M. E. Hodes and M. Mitchell
We encountered six female infants with a specific pattern of developmental
abnormalities of the urogenital and lower intestinal tracts. The anomalies
included ambiguous genitalia, lack of perineal openings, and mullerian and
urinary tract anomalies. Each patient had normal female chromosomes and
normal adrenal gland function. We believe that this combination of
anomalies represents a recognizable and specific sequence that is due to a
failure of migration to and/or fusion of the urorectal septum with the
cloacal membrane. This, in turn, we postulate, leads to persistence of the
cloaca and cloacal membrane and failure of normal differentiation of the
external genitalia. Persistence of the cloacal membrane results in absence
of the urethral and vaginal openings and an imperforate anus. We propose
calling this entity the urorectal septum malformation sequence.
