Recurrence of urorectal septum malformation sequence spectrum anomalies in siblings: time to explore the genetics.

Urorectal septum malformation sequence (URSM) is a pattern of malformation which encompasses abnormalities of the perineal orifices, external genitalia, genitourinary system, and anorectum. The spectrum ranges from a complete form with absence of perineal openings and persistent cloaca to milder/partial forms usually with one perineal opening and internal abnormalities of anorectum, urethra, and Müllerian structures. URSM is felt to arise due to abnormalities of the caudal mesoderm, which constitutes the urorectal septum. Here, we report two male siblings, affected with a spectrum of anomalies simulating URSM. This is the first report of recurrence of URSM in sibs. It suggests the existence of hitherto unknown genetic mechanisms for this pattern of malformation.