Homozygosity Mapping and Targeted Sanger Sequencing Identifies Three Novel CRB1 [Crumbs homologue 1] Mutations in Iranian Retinal Degeneration Families

Background: Inherited retinal diseases [IRDs] are a group of genetic disorders with high degrees of clinical, genetic and allelic heterogeneity. IRDs generally show progressive retinal cell death resulting in gradual vision loss

IRDs constitute a broad spectrum of disorders including retinitis pigmentosa and Leber congenital amaurosis. In this study, we performed genotyping studies to identify the underlying mutations in three Iranian families

Methods: Having employed homozygosity mapping and Sanger sequencing, we identified the underlying mutations in the crumbs homologue 1 gene. The CRB1 protein is a part of a macromolecular complex with a vital role in retinal cell polarity, morphogenesis, and maintenance

Results: We identified a novel homozygous variant [c.1053-1061del; p.Gly352-Cys354del] in one family, a combination of a novel [c.2086T>C; p.Cys696Arg] and a known variant [c.2234C>T, p.Thr745Met] in another family and a homozygous novel variant [c.3090T>A; p.Asn!030Lys] in a third family

Conclusion: This study shows that mutations in CRB1 are relatively common in Iranian non-syndromic IRD patients