Missense mutation at the C terminus of the PAX6 gene in ocular anterior segment anomalies.

PURPOSE To report a rare case of ocular anterior segment anomalies including uveal ectropion of the iris, invasion of the conjunctival epithelia into the cornea, and posterior embryotoxon with a missense mutation of the PAX6 gene. METHODS The authors performed polymerase chain reaction-single-strand conformation polymorphism analysis and sequencing of the PAX6 gene using genomic DNA of family members and more than 100 control subjects. RESULTS The A to G transition at nucleotide 1682 in exon 13 in the patient was identified in an allele that resulted in a Gln to Arg substitution (Q422R) at the C terminus of the protein. The mutation was not found in the parents, a sibling, or control subjects. CONCLUSIONS The mutation indicates that the proline-serine-threonine-rich domain at the C terminus of the PAX6 protein plays a role in ocular anterior segment morphogenesis.