Bladder exstrophy-epispadias complex: Investigation of suppressor of variegation, enhancer of zeste and Trithorax (SET) as a candidate gene in a large cohort of patients.

OBJECTIVE: The bladder exstrophy-epispadias complex (BEEC) describes a rare anterior midline defect with variable expression involving the infra-umbilical abdominal wall, including the pelvis, urinary tract and external genitalia. It is assumed that the underlying cause of BEEC is a multifactorial mode of inheritance; however, its aetiology remains unknown. Only a few BEEC patients with distinctive cytogenetic features such as numeric or structural chromosomal abnormalities have been reported. The observation of translocations concerning the region of chromosome 9q32-q34.1 in two patients implies that this region bears a candidate gene which, during early blastogenesis, governs the development of this primary field. In this context, we considered the suppressor of variegation, enhancer of zeste and Trithorax (SET) gene, located at chromosome 9q34, to be a good candidate, as the protein encoded is involved in the regulation of cell proliferation and differentiation. Moreover, SET expression was detected in embryonic kidney.

MATERIAL AND METHODS: A total of 33 patients affected with BEEC were analysed for mutations in the SET gene.

RESULTS: SET analysis did not reveal either a mutation or the presence of four single-nucleotide polymorphisms (dbSNP124) already described in the database.

CONCLUSIONS: The data obtained in this study most likely exclude the SET gene as a possible genetic cause of BEEC. Hence, other genes in this region may contribute to the development of this midline defect.