Effects of Inbreeding on the Prevalence of Chromosomal Disorders among the Population of Sloboda Ukraine

Abstract

An increase in inbreeding level and advanced parental age are factors that increase the risk of having children with structural and numerical chromosomal abnormalities due to altered frequency of recombination and impaired behavior of chromosomes in meiosis. There is limited information on the effects of inbreeding on human chromosomal and genomic mutations. The purpose of the study was to assess the effect of inbreeding on the prevalence of chromosomal abnormalities in the districts of the Kharkiv region. Materials and methods. The study was conducted in four districts of the Kharkiv region – Balakliia, Vovchansk, Zmiiv, and Krasnograd (administrative and territorial structure is given as of July 1, 2020). Based on the data of analysis of 1,582 marriages between opposite-sex couples mean age at marriage, marital distance, and the random inbreeding coefficient (FST) were estimated. Of 654 children (aged 0–17 years) included in the study, 39 had chromosomal disorders that was the basis for the calculation of the prevalence of chromosomal abnormalities. Results and discussion. In four districts, the mean age at marriage for local residents was 27.8 ± 0.1 years. Men were 2.9 years older than women at marriage. The marital distance was 320.4 ± 28.4 km, varying from 263.17 ± 48.39 km in the Balakliia district to 400.12 ± 79.97 km in the Vovchansk district. The random inbreeding coefficient FST was 0.001292. In rural settlements, the random inbreeding coefficient FST was by 17.2 times higher than in urban settlements. The index rose by 80 percent over the last seven years. The prevalence of chromosomal pathology among children and adolescents was 0.08%, ranging from 0.05% in the Vovchansk district to 0.14% in the Krasnograd district. Among the cases included, there were patients with Down syndrome, Klinefelter syndrome, Turner syndrome, and Prader-Willi syndrome. The most common nosological entity was Down syndrome. The prevalence of chromosomal abnormalities in villages was by 2.6 times higher than in towns. A strong positive relationship was established between the random inbreeding coefficients FST and the prevalence of chromosomal disorders in the study area (r = 0.904). Conclusion. Almost two-fold increase in the inbreeding rate in the mentioned districts in just past seven years may contribute to accumulation of burden of chromosomal disorders of the population due to the presence of a positive correlation between the study population indicators