Three novel aniridia mutations in the human PAX6 gene.
Aniridia ( iris hypoplasia ) is an autosomal dominant congenital disorder of the eye . Mutations in the human aniridia ( PAX6 ) gene have now been identified in many patients from various ethnic groups . In the study reported here we describe PAX6 mutations in one sporadic and five familial cases with aniridia . Of the four different mutations identified , one was identical to a previously reported mutation ( C-- > T transition at codon 240 ) , and three were novel  two in the glycine-rich region and one in the proline / serine / threonine-rich ( PST ) region . One PAX6 mutation found in the PST region was associated with cataracts in an aniridia family . Another splice mutation in the PST domain occurred in an aniridia patient with anosmia ( inability to smell ) . The six new aniridia cases reported here have mutations predicted to generate incomplete PAX6 proteins . These results support the theory that human aniridia is caused by haploinsufficiency of PAX6 . .
