Objective: To identify the mutation in the PAX6 gene in a family with congenital aniridia and cataract.
Methods: Total genomic DNA was extracted from peripheral blood leukocytes of 12 family members including three living affected members and 96 unrelated healthy controls. The coding exons 4-13 of the PAX6 gene with intronic flanking sequences were amplified by polymerase chain reaction (PCR). By comparing sequences of the affected members with that of normal individuals, the disease-causing mutation was detected by direct DNA sequencing.
Results: A PAX6 mutation was identified in the 3 patients, which did not exist in the unaffected members and unrelated healthy individuals. The nonsense mutation of C to T was detected at the nucleotide 1143, which converted the Arg codon (CGA) to a stop codon(TGA) (R261X) in exon 10.
Conclusion: The mutation (R261X) detected in the present study is considered to result in the occurrence of congenital aniridia and cataract in the Chinese family.