PRPH2 mutation as the cause of various clinical manifestations in a family affected with inherited retinal dystrophy

ABSTRACT

Background/Objectives: To reveal the underlying genetic defect in a complex family affected with different clinical features of inherited retinal dystrophy, we carried out whole exome sequencing followed by confirmatory molecular tests.

Materials and Methods: Complete ophthalmic examinations were performed for available affected family members. Whole exome sequencing, bioinformatics analysis, Sanger sequencing confirmation, and segregation analysis were done to identify the causative mutation.

Results: Clinical findings suggested fundus flavimaculatus as an early clinical feature progressing to an extensive chorioretinal atrophy involving the macula and mid-periphery of the fundus in one parent and central areolar chorioretinal dystrophy (CACD) as the most probable clinical diagnosis in another parent. Macular pattern dystrophy for one of their daughters and a Leber congenital amaurosis (LCA) like phenotype for the daughter with an early onset retinal dystrophy (EORD) phenotype was suggested. We found a known pathogenic nonsense variation in the PRPH2 gene (NM_000322: p.Gln239Ter). The parents with end stage fundus flavimaculatus and CACD diagnosis and their daughter with macular pattern dystrophy were heterozygous for the identified variant. The daughter affected with EORD/LCA like retinal dystrophy was homozygous for the same variation.

Conclusions: In this family, the same pathogenic variant in PRPH2 gene showed a wide range of clinical features of extensive chorioretinal macular atrophy with flecks as fundus falvimaculatus to CACD and macular pattern dystrophy in the heterozygous inheritance pattern and early onset/LCA like retinal dystrophy in the patient who was homozygous for the causative variant.

KEYWORDS:

• PRPH2 gene
• fundus flavimaculatus
• central areolar chorioretinal dystrophy
• macular pattern dystrophy
• Leber congenital amaurosis (LCA18)

Acknowledgments

We acknowledge the Ophthalmic Research Center of Shahid Beheshti University of Medical Sciences for funding this research and the investigated family members for their cooperation in this study.

Disclosure statement

The authors have no conflict of interest with the subject matter of this manuscript.