CRB1 Gene Mutation Causing Different Phenotypes of Leber Congenital Amaurosis in Siblings

PURPOSE: We report a rare case of CRB1gene mutation in two siblings (sisters) affected with the exact same genetic mutation on both CRB1genes resulting in varying phenotypes. CASE REPORT: CRB1gene mutation in this case has resulted in causing varying degrees of Leber congenital amaurosis (LCA) in both sisters with a more severe phenotype in the older sibling causing LCA-8 with retinitis pigmentosa spectrum in both eyes and a milder phenotype causing LCA-8 with less severe rod cone dystrophy in the younger sister. CONCLUSION: In summary, the mechanisms of varying phenotypes resulting from CRB1 genetic mutation are still not well understood. We concluded that the presence of different phenotypes associated with identical genotypic mutation of a single gene in siblings or in a family is important especially when dealing with retinal dystrophies.