Editorial: The genetics of inherited retinal diseases in understudied ethnic groups: Novel associations, challenges, and perspectives

Abstract

Editorial on the Research TopicThe genetics of inherited retinal diseases in understudied ethnic groups: Novel associations, challenges, and perspectives Inherited retinal dystrophies (IRDs) cover a broad array of rare retinal diseases with diversify in genetic bases and phenotypes, affecting roughly as many as one in 2,000 individuals (Chen et al., 2021). Night or color blindness, tunnel vision, and later development to total blindness are all common vision impairment manifestations of IRDs that usually worsen with age (Chen et al., 2021). Cases of IRDs may be syndromic if they are coupled with extra-ocular symptoms or nonsyndromic if they are restricted to the eye (Hartong, 2006;Berson, 2006;Dryja, 2006). Interestingly, IRDs include over 20 different phenotypes (Hartong et al., 2006). The age of onset, the rate of progression, and the underlying causal genes may assist in categorizing these distinct phenotypes (Hartong et al., 2006;Perea-Romero et al., 2021). Retinitis pigmentosa (RP) (OMIM 500004), also known as rod-cone dystrophy, is the most common non-syndromic IRD, affecting around 1.5 million individuals globally (Chen et al., 2021). Other non-syndromic forms include cone-rod dystrophies (OMIM 120970), Stargardt disease (OMIM 248200), X-linked retinoschisis (OMIM 312700) and many others. On the other hand, the most common syndromic form is Usher syndrome (USH) (OMIM 276900), a combination of hearing loss and RP (Castiglione and Moller, 2022).Although several genetic studies have identified novel IRDs-associated genes and genetic variations, most of these associations and gene prevalence data were based on cohorts in Western Europe and North America (Smirnov et al., 2021;Colombo et al., 2021). Although the genetic basis of IRDs varies among patient cohorts, even replication for the major findings is still lacking in understudied ethnicities (Jaffal et al., 2021). Growing evidence is continuously showing the importance of better investigating these ethnicities (Amish, Mennonites, Turks, Middle Eastern

The genetic landscape of inherited retinal dystrophies in Arabs

“…Every gene has its specific inheritance pattern and encodes a specific protein of different functions; structure, transmembrane, phototransduction, and visual cycle [ 9 ]. IRDs exhibits substantial genotypic and phenotypic differences across the world, analyzing this distribution in different populations is crucial for subsequent targeted therapeutic strategies [ 10 ]. Therefore, our goal was to identify the mutational spectrum and the IRDs distribution in the Arab countries globally, and per country, and to highlight the most prevalent mutations.…”