Sector Retinitis Pigmentosa caused by mutations of the RHO gene

Sector retinitis pigmentosa (RP) is an atypical form of RP in which only one or two quadrants of the retina are involved. The objectives of this study were to report the results of a molecular screening of five unrelated Chinese patients with sector RP and describe the clinical features observed in patients with RHO mutations.

Five probands that were clinically diagnosed with sector RP were recruited for genetic analysis. They underwent ophthalmic examinations, including best corrected visual acuity, fundus examination, visual field examinations, and electroretinography. A combination of molecular screening methods, including the targeted next-generation sequencing (TES) and sanger-DNA sequencing of RHO, were used to detect mutations. In silico programs were used to analyze the pathogenicity of all the variants.

Three RHO missense mutations (p.T17M, p.L31Q, and p.G106R) were identified in the five unrelated probands. The novel mutation p.L31Q was detected in three unrelated probands. All patients showed bilateral and symmetrical retinal degeneration in the inferior retina and had relatively good visual acuity. Patients with the p.L31Q mutation showed phenotypic variability and variable penetrance.

Our results indicate that RHO mutations are also common in Chinese patients with sector RP. The RHO gene should be given priority during mutation screening analysis for Chinese patients with sector RP.