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Retinitis pigmentosa caused by mutations in the ciliary MAK gene is relatively mild and is not associated with apparent extra‐ocular features
Author(s) -
Huet Ramon A. C.,
Siemiatkowska Anna M.,
Özgül Riza K.,
Yücel Didem,
Hoyng Carel B.,
Banin Eyal,
Blumenfeld Anat,
Rotenstreich Ygal,
Riemslag Frans C. C.,
Hollander Anneke I.,
Theelen Thomas,
Collin Rob W. J.,
Born L. Ingeborgh,
Klevering B. Jeroen
Publication year - 2015
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.12500
Subject(s) - retinitis pigmentosa , medicine , ophthalmology , missense mutation , electroretinography , ciliopathies , retinal pigment epithelium , nonsense mutation , outer nuclear layer , retinal , biology , genetics , mutation , phenotype , gene
Purpose Defects in MAK , encoding a protein localized to the photoreceptor connecting cilium, have recently been associated with autosomal recessive retinitis pigmentosa ( RP ). The aim of this study is to describe our detailed clinical observations in patients with MAK ‐associated RP , including an assessment of syndromic symptoms frequently observed in ciliopathies. Methods In this international collaborative study, 11 patients carrying nonsense or missense mutations in MAK were clinically evaluated, including extensive assessment of the medical history, slit‐lamp biomicroscopy, ophthalmoscopy, kinetic perimetry, electroretinography ( ERG ), spectral‐domain optical coherence tomography ( SD ‐ OCT ), autofluorescence imaging and fundus photography. Additionally, we used a questionnaire to evaluate the presence of syndromic features and tested the olfactory function. Results MAK ‐associated RP is not associated with syndromic features, not even with subclinical dysfunction of the olfactory apparatus. All patients experienced typical RP symptoms of night blindness followed by visual field constriction. Symptoms initiated between childhood and the age of 43 (mean: 23 years). Although some patients experienced vision loss, the visual acuity remained normal in most patients. ERG and ophthalmoscopy revealed classic RP characteristics, and SD ‐ OCT demonstrated thinning of the overall retina, outer nuclear layer and photoreceptor–pigment epithelium complex. Conclusion Nonsense and missense mutations in MAK give rise to a non‐syndromic recessive RP phenotype without apparent extra‐ocular features. When compared to other retinal ciliopathies, MAK ‐associated RP appears to be relatively mild and shows remarkable resemblance to RP 1 ‐associated RP , which could be explained by the close functional relation of these proteins.