Purpose: To identify the disease-causing gene in a four-generation Chinese family affected with autosomal dominant aniridia and cataract.
Methods: All patients underwent full ophthalmic examination. For mutation analysis, a partial coding region (exons 5-14) of paired box gene 6 (PAX6) was sequenced with DNA from the proband. Single-strand conformation polymorphism analysis for exon 5 of PAX6 was performed to demonstrate co-segregation of the PAX6 mutation with aniridia in all family members and the absence of the mutation in the normal controls.
Results: The proband and other patients in the family were affected with aniridia accompanied with congenital cataract. A novel heterozygous PAX6 mutation in exon 5 (c.475_491del17, p.Arg38ProfsX12) was identified, which was predicted to generate a frameshift and create a premature termination codon. This mutation co-segregated with the affected individuals in the family and did not exist in unaffected family members and 100 unrelated normal controls.
Conclusions: A novel deletion mutation in the PAX6 gene was identified in a Chinese family with aniridia and congenital cataract. Our study expands the mutation spectrum of PAX6.