Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Beirut, Lebanon.
Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon.
BMC Med Genomics. 2023 May 1;16(1):89. doi: 10.1186/s12920-023-01518-7.
Inherited retinal dystrophies (IRDs) are a major cause of vision loss. Altogether are highly heterogeneous genotypically and phenotypically, exhibiting substantial differences worldwide. To shed more light on these conditions, we investigated the genetic and phenotypic landscape of IRDs in the Arabs globally and per country.We analyzed 1,621 affected individuals from 16 Arabic countries reported in 198 articles. At the phenotypic level, rod-cone dystrophy (RCD) and Usher syndrome were the most prevalent conditions among non-syndromic and syndromic IRDs. At the gene level, TULP1, ABCA4, RP1, CRB1, MYO7A, RPE65, KCNV2, and IMPG2 were the most mutated genes. Interestingly, all except CRB1 were highly prevalent because they harbored founder mutations, implying that consanguinity is a major determinant in Arab countries. Of note, ~ 93% of the investigated individuals carried homozygous mutations. The country analysis for the IRDs conditions and their associated genotypes revealed that whereas Leber Congenital Amaurosis, RCD, and USHER syndrome were widely distributed, bestrophinopathies and non-syndromic hearing loss were restricted to specific countries (till now).This study could be a starting point for initiating suitable health policies towards IRDs in the Arab world. The high degree of homozygosity urges the need for genetic counsellors to provide personalized information and support the affected individuals.
遗传性视网膜病变（IRDs）是导致视力丧失的主要原因。这些疾病在基因型和表型上高度异质，在全球范围内表现出显著的差异。为了更深入地了解这些疾病，我们对全球阿拉伯人群中的 IRD 的遗传和表型特征进行了研究，并按国家进行了分析。
我们分析了 198 篇文章中报道的来自 16 个阿拉伯国家的 1621 名受影响个体。在表型水平上，杆锥细胞营养不良（RCD）和 Usher 综合征是非综合征性和综合征性 IRD 中最常见的疾病。在基因水平上，TULP1、ABCA4、RP1、CRB1、MYO7A、RPE65、KCNV2 和 IMPG2 是突变最多的基因。有趣的是，除了 CRB1 之外，所有这些基因都非常常见，因为它们携带有创始突变，这意味着近亲结婚是阿拉伯国家的一个主要决定因素。值得注意的是，调查的个体中有~93%携带纯合突变。对 IRD 疾病及其相关基因型的国家分析表明，虽然 Leber 先天性黑矇、RCD 和 USHER 综合征广泛分布，但 Best 病和非综合征性听力损失仅限于特定国家（迄今为止）。
这项研究可能是在阿拉伯世界启动针对 IRD 的适当卫生政策的起点。高度的纯合性迫切需要遗传咨询师提供个性化信息，并为受影响的个体提供支持。
