Abstract
Purpose :
Elucidating the prevalence and burden of IRD-causing genes across different populations is important in the current era of precision medicine. In the past decade, there has been a growing number of population-based and molecularly-diagnosed IRD cohorts. Hence, in this review and meta-analysis, we aim to establish the most common inherited retinal diseases (IRD) globally and regionally.
Methods :
A systematic review of relevant studies published up to December 2022 was conducted using PubMed, Medline, Web of Science, and Scopus. Missing data or unpublished data were further requested from respective IRD study groups. To estimate the prevalence of each IRD-causing gene globally and regionally, we performed a random effect linear mixed model meta-regression analysis with stepwise model selection. In this model, the genetically solved rate was incorporated as a fixed effect; the region in which the study was conducted and sampling errors were incorporated as random effects.
Results :
The analyses included data from 22 studies published between 2013 to 2022, with a total number of 21 530 probands. The studies were published from 19 countries in 4 regions: Europe (11 studies), Western-Pacific (6 studies), America (4 studies), and East Mediterranean (1 study). The median genetically solved rate was 61% (range: 32% to 86%). Globally, amongst IRD cases, the 5 most common IRD genes were: ABCA4 (12.9%; 95% CI: 9.6-17.1), USH2A (6.8%; 95% CI: 5.4-8.4), RPGR (2.7%; 95% CI: 2.3-3.3), EYS (2.1%; 95% CI: 1.4-3.0) and RHO (1.9%; 95% CI: 1.4-2.5. Similarly, the 5 common genes in Europe were ABCA4, USH2A, RPGR, RHO, and PRPH2; and the most common genes in America region were ABCA4, USH2A, RPGR, EYS, and CRB1. On the contrary, the common IRD genes in Western-Pacific region were: EYS (%), CYP4V2, USH2A, ABCA4, and RPGR.
Conclusions :
This review comprehensively pools a rapidly growing body of knowledge on IRD prevalence and provides unprecedented insight into the genetic landscape IRDs globally and regionally. These findings would aid in the projection of potentially treatable IRD patients and relevant health resource allocations.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.