THE PREVALENCE OF PAX2 MUTATIONS IN PATIENTS WITH ISOLATED COLOBOMAS OR COLOBOMAS ASSOCIATED WITH UROGENITAL ANOMALIES

The PAX2 gene is mutated in patients with ocular colobomas, vesicouret eral reflux (WR), and kidney anomalies (renal-coloboma syndrome, OMIM 120330). The three abnormalities which make up this syndrome also occu r in isolation, but the causal genes are not known. PAX2 encodes a tra nscription factor of the paired box class of DNA binding proteins, imp ortant for the development of the urogenital tract, optic nerve and ad jacent retina, inner ear, and CNS. In this paper we have investigated the prevalence of PAX2 mutations in patients with ocular colobomas, mi crophthalmos, or retinal anomalies, either in isolation or with associ ated urogenital anomalies. Using PCR-SSCP, most or all exons of PAX2 w ere examined in blood DNA from 99 patients who have either ocular anom alies alone or a combination of ocular and urogenital conditions. PAX2 mutations were not detected in patients with ocular colobomas, either in isolation or with associated abnormalities, except in one patient with typical renal-coloboma syndrome. We conclude that PAX2 mutations are unlikely to be common in patients with ocular colobomas in isolati on or in patients with ocular colobomas and associated anomalies, exce pt for patients with typical renal-coloboma syndrome where PAX2 is kno wn to be the aetiological cause.