This 49YO male has a history of MFRP-related retinitis pigmentosa (RP). We have followed him for 13 years with stable findings of bilateral nanophthalmos (+18D hyperopia, axial lengths 14.82mm OD and 15.14 OS), optic disc drusen (ODD), and choroidal folds. He has compound heterozygosity for 2 pathogenic variants in the MFRP gene.
Optos color RG imaging in his OD shows pigmentary changes throughout the midperiphery along with an ill-defined disc margin. Fundus autofluorescence (FAF) shows variable hyper- and hypo-FAF in the midperiphery. Disc drusen are noted on a more magnified view, which hyper-FAF. Macular OCT shows a central fold, choroidal thickening, and chorioretinal folds. Identical findings were present in his OD (not shown).
Learning Points:
The MFRP (membrane frizzled-related protein) is expressed in the RPE and ciliary epithelium. MFRP functions as a molecular hub on the RPE apical membrane, coordinating protein trafficking and lipid homeostasis. Loss of MFRP leads to DHA accumulation in the RPE, downregulation of visual cycle genes and phototransduction genes, and progressive photoreceptor degeneration.
Biallelic MFRP mutations cause a well-characterized autosomal recessive retinitis pigmentosa (RP) syndrome with nanophthalmos and ODD (Li et al, BJO 2024;108;1679-1687). These eyes are at high risk of angle-closure glaucoma, usually requiring prophylactic laser peripheral iridotomy.
