DNA diagnosis in a family with autosomal dominant aniridia

A large family with autosomal dominant aniridia is described. One of the family members presented with reduced visual acuity, nystagmus, slightly distorted macular reflex, but normal irides and clear media. Because of the high variability in expression of aniridia, even within family, a diagnosis of aniridia could not be excluded. However linkage analysis using tightly linked chromosome 11p13 markers flanking the aniridia locus (catalase, D11S151, and D11S325) made it highly unlikely that this patient inherited the aniridia gene from his affected mother.