Abstract: Objective: To study the clinical features of two pedigrees of families with autosomal dominant aniridia, and to identify the pathogenic genes of the 2 families. Methods: All affected members underwent interrogation and ophthalmological examinations. Screening for PAX6 gene mutations was carried out in the 2 families. Family 2 in which no mutation was detected was also detected by exon capture and whole exome sequencing. Results: The patients of Family 1 pedigrees were completely consistent with the clinical features of aniridia, and the patients of Family 2 also had furthermore the phenotype of ptosis. Mutation screening showed that there was a known PAX6 gene mutation c.718C>T (p.Arg240*) in Family 1, but no mutation of PAX6 gene and other known genes were detected in Family 2. Conclusions: A PAX6 gene mutation (p.Arg240*) is detected in pedigrees of Family 1, but no disease-causing gene is yet detected in pedigrees of Family 2, denoting there is a novel genetic heterogeneity in aniridia.

Key words: Aniridia, Human paired box gene 6, Arg240*, Exome-sequencing