Cloacal exstrophy in an infant with 9q34.1-qter deletion resulting from a de novo unbalanced translocation between chromosome 9q and Yq

Abstract

Cloacal exstrophy is a rare malformation, belonging to a spectrum of birth defects, which, in order of severity, includes phallic separation with epispadias, pubic diastasis, bladder exstrophy, and cloacal exstrophy. This malformation overlaps the OEIS complex (O = omphalocele, E = bladder exstrophy, I = imperforate anus, S = spinal defects). The etiology of cloacal exstrophy is unknown to date. It may result from either a single defect of early blastogenesis or a defect of mesodermal migration during the primitive streak period. We report an infant with cloacal exstrophy, exomphalos, right kidney agenesis, ambiguous external genitalia, and axial hypotonia. The karyotype showed a de novo unbalanced translocation between the long arm of chromosome 9 and the long arm of chromosome Y resulting in a 9q34.1-qter deletion. Reviewing the literature, we did not find any observation of cloacal exstrophy associated with a structural chromosomal abnormality. The steroidogenic factor 1 (SF1) gene, included in the deleted region, was a good candidate gene but no pathogenic mutation was found by direct sequencing. We hypothesize that another gene, expressed early in embryogenesis and responsible for cloacal exstrophy, is present in the 9q34.1-qter region.