Abstract
Purpose:
Aniridia is a dominantly inherited congenital disorder which is associated with mutations or deletions of the paired box gene 6 (PAX6). The mutations in PAX6 gene play an important role in pathogenesis of anterior segment anomalies, such as aniridia. In this study, molecular genetic analysis of PAX6 gene was performed to detect the genetic defects in a Chinese family with congenital aniridia.
Methods:
All members enrolled in this pedigree underwent a complete general ophthalmologic examinations. Genomic DNA was extracted from their peripheral venous blood. Exons of PAX6 gene were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database.
Results:
Aniridia, nystagmus and ptosis were found in all patients of this family, but the severity was different among these patients. A rare mutation c.2T>A(p.M1K) in exon 4 of PAX6 was identified in all affected individuals but not in asymptomatic members. This mutation causes ATG (the initiation codon) for methionine changing to AAG which is the codon for lysine. Mutation occurred in the initiation codon may completely blocked the translation of the protein.
Conclusions:
This study suggests that the mutation c.2T>A (p.M1K) is likely responsible for the pathogenesis of congenital aniridia in this pedigree. To our knowledge, this is the first report of M1K mutation in PAX6 in Chinese pedigree with congenital aniridia, and the second report worldwide.