Introduction: We present two patients, the proband and the affected sibling, with biallelic CRB1 mutations leading to a macular dystrophy.
Case presentation: We present two patients, the proband and the affected sibling, with biallelic CRB1 mutations leading to a macular dystrophy. With 15 years of follow-up for the proband, we illustrate the natural history of CRB1 maculopathy based on clinical examination, multimodal imaging, and electrophysiology. In addition, we demonstrate the wide phenotypic spectrum of the condition with the affected sister harboring the same variants but with much milder phenotypic manifestations.
Conclusion: In addition to a previously described pathogenic variant, Ile167_Gly169del, one pathogenic missense variant in CRB1, Lys801Ter, not previously associated with macular dystrophy, is reported here. While CRB1 mutations have been more commonly described in retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA), we demonstrate that mutations in CRB1 can cause a maculopathy with initial features similar to fenestrated sheen macular dystrophy (FSMD) that later evolves into severe macular atrophy.
Keywords: CRB1 mutation; Macular dystrophy; Retina; Retinal degenerative diseases.