Mutation analysis of PAX6 gene in three Chinese families with aniridia

Abstract

Background Human paired box gene 6 (PAX6) encodes a transcriptional regulator.It is essential for eye and brain morphogenesis.Mutation of PAX6 gene is responsible for many congenital ocular malformations,such as aniridia.Aniridia is a autosomal dominant inheritance mode. Objective In this study,PAX6 gene mutation was analyzed in three Chinese families with aniridia through polymerase chain reaction (PCR) and sequencing. Methods The blood specimens were collected from 5 suffers and normal individuals of 3 aniridia families to extract DNA.The sequences of extron 4-13 were designed based on PAX6 gene.The primer was amplified by PCR and sequenced and compared with the known PAX6 gene sequence.This study complied with Declaration of Helsinki and approved by ethic committee of Sichuan University.Written informed consent was obtained from each individual before any medial examination. Results There were 5 suffers in the 3 families.A heterozygous mutation (c.718 C＞T) in PAX6 gene was identified in 2 patients of family A.This mutation caused an amino acid substitution of arginine to termination codon at position 240 ( p.Arg240X) of PAX6 protein.No similar change in the normal families.No any the alteration of PAX6 gene was detected in family B whatever suffers and normal individuals.In family C,a deletion mutation of c.331 delG ( p.Val111 SerfsX13 ) in PAX6 gene was found.The deletion of one base caused frame shift mutation of PAX6 protein,and no such mutation was seen in other families. Conclusions Mutation of PAX6 gene appeares to be causative mutations of the disease in family A and C. Key words: Human paired box gene; Aniridia; Polymerase chain reaction; Gene mutation