Analysis of the PAX6 Gene Mutation and Clinical Characteristics in a Chinese Tujia Family with Congenital Aniridia

Abstract

Objective: To observe the clinical characteristics and identify a potential mutation of the PAX6 gene responsible for congenital aniridia in a Chinese Tujia family in central China. Methods: In this experimental study, data from a detailed family history and ophthalmologic examinations were collected. Genomic DNA was extracted from the peripheral blood of seven family members and 100 healthy individuals (50 Tujia and 50 Han nationalities). The coding regions and flanking sequence of the PAX6 gene of the propositus members were amplified by PCR and subjected to DNA sequencing. The genetic sequence of the mutant site of the unaffected family members and control group's individuals were verified. Results: The clinical characteristics of the affected family members with iris hypoplasia with or without cataract, nystagmus, foveal dysplasia or keratopathy were analyzed. Cataract and keratopathy were aggravated with age. A heterozygous mutation (c.357+1G > A) was identified at the junction of exon 3 and intron 3 in four patients but not in the unaffected family members or 100 healthy individuals. Conclusions: The degree of iris hypoplasia is variable. The c.357+1G > A heterozygous mutation of PAX6 is found to underlie the aniridia in an autosomal dominant inheritance manner. Key words: PAX6 gene; congenital aniridia; heterozygous mutation; tujia nationality