CERKL-Associated Retinal Dystrophy: Genetics, Phenotype, and Natural History.
Daich Varela M., Duignan ES., De Silva SR., Ba-Abbad R., Fujinami-Yokokawa Y., Leo S., Fujinami K., Mahroo OA., Robson AG., Webster AR., Michaelides M.
PurposeTo analyze the clinical characteristics, natural history, and genetics of CERKL-associated retinal dystrophy in the largest series to date.DesignMulticenter retrospective cohort study.SubjectsForty-seven patients (37 families) with likely disease-causing CERKL variants.MethodsReview of clinical notes, ophthalmic images, and molecular diagnosis from 2 international centers.Main outcome measuresVisual function, retinal imaging, and characteristics were evaluated and correlated.ResultsThe mean age at the first visit was 29.6 ± 13.9 years, and the mean follow-up time was 9.1 ± 7.4 years. The most frequent initial symptom was central vision loss (40%), and the most common retinal feature was well-demarcated areas of macular atrophy (57%). Seventy-seven percent of the participants had double-null genotypes, and 64% had electrophysiological assessment. Among the latter, 53% showed similar severity of rod and cone dysfunction, 27% revealed a rod-cone, 10% a cone-rod, and 10% a macular dystrophy dysfunction pattern. Patients without double-null genotypes tended to have fewer pigment deposits and included a higher proportion of older patients with a relatively mild electrophysiological phenotype. Longitudinal analysis showed that over half of the cohort lost 15 ETDRS letters or more in ≥ 1 eye during the first 5 years of follow-up.ConclusionsThe phenotype of CERKL-retinal dystrophy is broad, encompassing isolated macular disease to severe retina-wide involvement, with a range of functional phenotypes, generally not fitting in the rod-cone/cone-rod dichotomy. Disease onset is often earlier, with more severe retinal degenerative changes and photoreceptor dysfunction, in nullizygous cases.Financial disclosure(s)Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.