PRPF31-related retinitis pigmentosa and asymptomatic carriers
Reviewed by Ian Reekie

The authors present a study of 21 patients with variants in the PRPF31 gene classified as pathogenic or likely pathogenic. These variants are caused by autosomal dominant retinitis pigmentosa (RP-11). Between January 2020 and November 2021 patients underwent tests of retinal function including Goldmann visual fields (GVF), full field ERGs, dark adaptometry and full field stimulus threshold testing. Retinal structural changes were evaluated by clinical examination and by OCT. Participants were grouped into symptomatic and asymptomatic (normal visual acuity and normal visual field) cohorts. Retinitis pigmentosa due to mutations in PRPF31 has often been reported to be incompletely penetrant. Four out of five asymptomatic carriers of PRPF31 mutations in this study had abnormal full field ERGs and one also had marked structural changes on macular OCT, showing some pathological changes occur even in symptomatically non-penetrant cases. For symptomatic patients neither dark adaptometry nor full field ERGs were useful in assessing disease progression. By contrast, full field stimulus threshold did correlate well with GVF area and moderately well with visual acuity. The study is limited by the small numbers of patients enrolled, though this is not unusual for studies of rare diseases. The authors make a case for the use of full field stimulus threshold testing for disease monitoring and as an outcome measure for future trials. As the field moves towards having some viable treatments for inherited retinal diseases it will become imperative to have agreed measures of disease severity for trials of treatment efficacy.

Clinical characterization of patients with PRPF31-related retinitis pigmentosa and asymptomatic carriers: a cross-sectional study.
Lisbjerg K, Bertelsen M, Grønskov K, Kessel L.
OPHTHALMIC GENETICS
2023;44(5):456–64.