Genotype and Phenotype Characteristics of Major Genes Causing Inherited Retinal Diseases in Different Ethnic Groups of the Israeli Population

Inherited retinal dystrophies (IRDs) are a heterogeneous group of diseases, causing visual loss, affecting about 5.5 million people worldwide. Prevalence of IRD in Israel is estimated between 1:1000 and 1:2000 individuals. IRDs are divided into subgroups according to the mutated genes causing the disorder and/or according to the main cell type, which is damaged and does not function properly, i.e., rod-cone dystrophies, the most common example in this group is retinitis pigmentosa; cone dystrophies, best known example is achromatopsia. Every population has its unique mix-up of genetic variants that cause different types of IRD. Israel’s population is mainly made up of Jews and Arabs, and each is further subdivided into subethnicities, with their specific genetic characteristics. The Israeli IRD Consortium (IIRDC) was created in 2013, with the aim to recruit patients and families with IRDs, to characterize each patient genetically and phenotypically, to provide opportunities for genetic counseling to patients and their family members, and finally to facilitate suitable therapies. In this chapter, we elaborate on the demographics of the Israeli population, provide a brief historical summary, and highlight relevant gene variants that are characteristic of specific subethnicities in the Israeli population.