Genetic epidemiological study of three district populations in Chuvashia

Comprehensive population genetic and medical genetic studies were performed in three raions (districts) of Chuvashia. The population of these district s is more than 90% Chuvash. About 70% of the families that completed reprod uction had two or three children. The proportion of families with four or m ore children was 18%. The duration of generation was 27.6 years. The differ ential fertility and differential mortality indices in the Chuvash populati on were estimated at 0.33 and 0.076, respectively. The total index of diffe rential selection was 0.403, which is typical of modern urbanized populatio ns. Mean values of local inbreeding calculated from Malecot's model of isol ation by distance were 0.00124 and 0.00377 for the urban and rural populati ons, respectively, of the districts studied. The prevalence rates of autoso mal dominant (AD), autosomal recessive (AR), and X-linked diseases were fou nd to be 0.47, 0.52, and 0.35 per 1000, respectively, in the urban populati on and 1.62, 1.14, and 0.31 per 1000, respectively, in the rural population . Significant cot-relation between the local inbreeding and prevalence rate s of AD and AR diseases was found. A total of 43 AD and 43 AR diseases were identified. Some of them were not found in previous studies on other popul ations.