The genetic load and diversity of monogenic hereditary diseases (HD) in the Russian population of Karachay-Cherkess Republic (KCHR), living in 10 administrative and municipal divisions, were studied. The total size of the population surveyed was 410,367 people, including 134,756 Russians. In total, 385 patients from 281 families were registered among Russians of KCHR. Genetic load of AD, AR, and X-linked diseases (3.01 ± 0.32, 1.98 ± 0.26, and 1.23 ± 0.29, respectively) are more than twice higher in cities and municipal centers than in corresponding rural regions (1.00 ± 0.10, 0.89 ± 0.09, and 0.42 ± 0.09, respectively). The diversity of HD was 96 nosological forms: 56 diseases with AD type of inheritance (193 patients from 126 families), 28 clinical forms with AR (152 patients out of 124 families) and 12 diseases with the X-linked type of inheritance (40 affected from 31 families). A comparative analysis of the diversity of AD and AR HD with the previously studied populations and ethnic groups of the European part of Russia (Russians of 7 regions, 5 peoples of the Volga-Ural region, and 5 populations of the North Caucasus) was conducted, showing that Russians in the KCHR preserved genetic load with other Russian populations and its difference from the same mutation pool of Karachays and Circassians.
Keywords: Genetic epidemiology; Karachay-Cherkess Republic; Russians; diversity of monogenic hereditary diseases; genetic load.