Eye anomalies and neurological manifestations in patients with PAX6 mutations

Mutations in the paired box 6 (PAX6)gene cause a wide variety of eye anomalies, including aniridia. PAX6 mutations are not well described in the Chinese population so this study is aimed at exploring the role of PAX6 mutations in Taiwanese patients with congenital eye anomalies.

Seventeen patients with single or multiple congenital eye anomalies were enrolled. Genomic DNA was prepared from venous blood leukocytes, and the coding regions of PAX6 were analyzed by PCR and direct sequencing. Clinical manifestations of the patients were then correlated to PAX6 mutations.

Five PAX6 mutations were identified in one case each. Three mutations c.317T>A (p.L106X), c.142-1G>T, and c.656del10 (p.Q219QfsX20) were novel and the other two, c.331delG (p.V111SfsX13) and c.949C>T (p.R317X), have been reported. All five cases had aniridia; three had other eye anomalies; and four had developmental delay. Only one case had other affected family members. In the ten cases that had no PAX6 mutation, only one had aniridia.

Both novel and known PAX6 mutations were identified in the current study, and PAX6 mutations were closely associated with aniridia. Absence of a positive family history does not exclude PAX6 mutation. The frequent occurrence of developmental delay in patients with PAX6 mutation argues for a prompt diagnosis of the disease.