The Urorectal Septum Malformation Sequence (URSMS) covers a spectrum of malformations that may affect several different organs, primarily in the abdomen, pelvis and perineum. The complete form is associated with perinatal mortality.
Pathogenesis: deficiency in caudal end of the mesoderm and/or defect in the cloacal endoderm, peri-cloacal mesenchyme and genital ectoderm
Genes implicated include:
(1) TMEM132A
(2) NALCN
(3) HOXD9
(4) SLIT2
Types:
(1) full or complete type
(2) partial or intermediate type
(3) mild
Gastrointestinal anomalies include:
(1) anal agenesis
(2) urorectal septum hypoplasia
(3) persistent cloaca
Urinary tract anomalies
(1) renal agenesis
(2) dysplastic kidneys
(3) horseshoe kidney
(4) hypoplastic, ectopic kidney
Genital malformations
(1) agenesis or hypoplasia
(2) Mullerian duct abnormalities
Skeletal abnormalities:
(1) sacral agenesis
(2) lumbosacral dysraphism
The patient often has other significant malformations that may affect the brain, aortic arch, heart, lung and esophagus.
