Epidemiology of monogenic hereditary diseases in Rostov oblast: Population dynamic factors determining the differentiation of the load of hereditary diseases in eight districts

A genetic epidemiological study has been carried out in eight raions (districts) of Rostov oblast (region) of Russia: Tsimlyansk, Volgodonskoi, Tselina, Egorlykskaya, Millerovo, Tarasovskaya, Rodionovo-Nesvetaiskaya, and Matveevo-Kurgan raions. The population structure (the parameters of the isolation by distance model, ethnic assortative marriage, random inbreeding (F _ST), endogamy index, and ie) and the genetic demographic characteristics of the regional population (vital statistics, Crow’s index, and its components) have been analyzed. The total sample size was 320 925 subjects (including 114 106 and 206 816 urban and rural residents, respectively). The load of the main types of Mendelian diseases (autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases) has been calculated for the total sample from eight districts and separately for the urban and rural populations. Substantial differences between individual districts in the AD and AR genetic loads have been found, especially upon separation into urban and rural samples. The results of correlation analysis suggest that migration and genetic drift are the main factors of genetic differentiation of populations with respect to the prevalence of hereditary diseases.     

The load and diversity of hereditary diseases in four raions of Rostov oblast

The results of a medical genetic survey of the population of four raions (176535 individuals) of Rostov oblast (Dubovsky, Zimovnikovsky, Myasnikovsky, and Krasnosulinsky raions) are presented. The load of autosomal dominant (AD), autosomal recessive (AR), and X-linked hereditary diseases for urban and rural population was calculated, and the diversity of monogenic hereditary diseases (MHD) was reviewed. The nosological spectrum of MHD constituted 117 diseases (63 diseases with AD inheritance; 38, with AR inheritance; and 16, with X-linked inheritance). The analysis showed that the incidence of MHD among the population of Rostov oblast was 1: 336. Considerable differentiation in the prevalence rates of MHD (AD, AR, and X-linked pathologies) among certain raions was revealed.     

Genetic epidemiological study of Bashkortostan Republic: The diversity of monogenic hereditary diseases in five districts

The diversity of monogenic hereditary diseases (HDs) (autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases) has been studied in five districts of Bashkortostan Republic: Burzyanskii, Abzelilovskii, Baimak, Salavatskii, and Arkhangel’skoe raions. The spectrum of HDs comprised 144 diseases, including 83, 48, and 13 AD, AR, and X-linked diseases. Most of them were found earlier during studies in ten other regions of Russia (Kirov, Kostroma, Tver’, Bryansk, and Rostov oblasts, and Krasnodar krai, and the republics of Adygea, Marii El, Udmurtia, and Chuvashia). Foci of local accumulation of some AD, AR, and X-linked diseases have been found in individual districts. Data on the gene frequencies for the HDs have been used for cluster analysis, which has shown the gene geographic position of Bashkirs among nine ethnic populations of Russia: Russians (Kostroma, Kirov, and Rostov oblasts and Krasnodar krai), Chuvashes (Chuvashia), Adygeans (Adygea), Maris (Marii El), Udmurts (Udmurtia), and Bashkirs (Bashkortostan).     

Population genetics of hereditary diseases in the child population of the Republic of Bashkortostan, Chuvashia, and Udmurtia

The results of integrated study of the genetic structure and prevalence of monogenic hereditary diseases (MHDs) in the child population of three republics of Russia are summarized. Eight raions (districts) of the Republic of Bashkortostan and six districts of each Republic of Chuvashia and Republic of Udmurtia has been surveyed. The total population surveyed was 782184 people, with children accounting for 24.67% of them (192992 children). The loads of autosomal dominant (AD), autosomal recessive (AR), and X-linked MHDs have been calculated separately for urban and rural populations; differences between individual populations in the MHD load have been found. The differentiation of subpopulations with respect to MHD prevalence is explained by differences in the degree of subdivision. The MHD spectrum in the child population of the three republics comprises 222 disease entities, including 121 AD, 83 AR, and 18 X-linked diseases. Group of highly prevalent MHDs in regional child populations have been determined. The mean fitness of MHD patients in Bashkortostan has been calculated; it is 0.87, 0.04 and 0.16 for AD, AR, and X-linked diseases, respectively. Analysis has demonstrated that the prevalence rates of MHDs in the child populations of the republics of Chuvashia, Udmurtia, and Bashkortostan are 1, 1.2, and 1.4%, respectively.     

Hereditary deafness in Kirov oblast: a genetic epidemiological study

The results of a genetic epidemiological study of hereditary deafness (HD) in ten raions (districts) of Kirov oblast (administrative region), Russia, are presented. A total of 122 075 people have been examined. Segregation analysis of all families with diagnosed HD has demonstrated a good fit to either the autosomal dominant (AD) or autosomal recessive (AR) mode of inheritance. The total prevalence rates of AD and AR HDs, as well as the specific prevalence rates of nonsyndromic and syndromic forms of HD, have been calculated for the population often raions. The HD prevalence rate in Kirov oblast has been found to be 1 : 1043 people (1 : 1453 and 1 : 3699 for the nonsyndromic and syndromic forms, respectively). This value has been found to vary in different raions, which is explained by differences in the genetic subdivision levels of the populations studied; the correlation coefficient between the HD load and random inbreeding (F(ST)) in district populations is r = 0.81 +/- 0.22. The diversity of syndromic hearing disorders is described.     

Hereditary deafness in Kirov oblast: A genetic epidemiological study

The results of a genetic epidemiological study of hereditary deafness (HD) in ten raions (districts) of Kirov oblast (administrative region), Russia, are presented. A total of 122 075 people have been examined. Segregation analysis of all families with diagnosed HD has demonstrated a good fit to either the autosomal dominant (AD) or autosomal recessive (AR) mode of inheritance. The total prevalence rates of AD and AR HDs, as well as the specific prevalence rates of nonsyndromic and syndromic forms of HD, have been calculated for the population of ten raions. The HD prevalence rate in Kirov oblast has been found to be 1: 1043 people (1: 1453 and 1: 3699 for the nonsyndromic and syndromic forms, respectively). This value has been found to vary in different raions, which is explained by differences in the genetic subdivision levels of the populations studied; the correlation coefficient between the HD load and random inbreeding (F _ST) in district populations is r = 0.81 ± 0.22. The diversity of syndromic hearing disorders is described.     

Genetic epidemiological study of monogenic hereditary diseases in the Republic of Tatarstan: Population dynamic factors determining the differentiation of the load of hereditary diseases in five districts

A genetic epidemiological study has been performed in five districts of the Republic of Tatarstan, Russia: Arsky, Atninsky, Kukmorsky, Buinsky and Drozhzhanovsky raions. The total size of the population surveyed is 188397 people. Tatars accounted for 77.13% of the population analyzed (145466 people) and were represented by two main ethnic groups: Kazan Tatars and Mishars. The medical genetic study encompassed the total population of the districts, irrespective of ethnicity, and was carried out according to the standard protocol developed in the Laboratory of Genetic Epidemiology of the Research Center for Medical Genetics of the Russian Academy of Medical Sciences. After segregation analysis, the prevalence rates of the main types of monogenic hereditary disorders (MHDs), i.e., autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases, have been calculated for the total population of the five districts and for Tatars alone. The prevalence rates of AD, AR, and X-linked diseases considerably vary in different subpopulations. The largest difference in the MHD prevalence rate has been found between the rural and urban populations. The overall prevalence rate of MHDs was one patient per 293 urban residents and populations and one patient per 134 rural residents, with a wide variation between subpopulations, from 1: 83 people in the rural population of Atninsky raion to 1: 351 people in the town of Kukmor. Comparison of the MHD prevalence rate in Tatars with those in populations surveyed earlier has shown that the characteristics of the load of MHDs in the Tatar population are similar to those in some districts of the republics of Bashkortostan, Udmurtia, Mari El, and Chuvachia. In Russian populations of European Russia, the MHD prevalence rates are substantially lower. Correlation analysis has shown high (r = 0.5?C0.9) significant correlations between the local inbreeding (a), the im index, the random inbreeding (F _ST), and the AD and AR prevalence rates in the Tatar population. This analysis has demonstrated that genetic drift is the main population dynamic factor determining the MHD load in the Tatar population.     

Genetic structure of the Udmurt population

Integrated study of the genetic structure of the Udmurt population with respect to different genetic systems has been performed. Data on the genes of genetic diseases, abiotic parameters analyzed by population statistic methods, and DNA polymorphism are summarized. The populations of six raions (districts) of Udmurt Republic (the Mozhga, Malaya Purga, Sharkan, Debesy, Igra, and Glazov raions) have been studied. The total population studied was 267 655 people (an urban population of 150 119 people and a rural population of 117 536 people), including 155 346 Udmurts. The population structure has been studied in six districts on the basis of the vital statistics, Crow’s indices, Malecot’s isolation by distance parameters, ethnically assortative marriage parameters, endogamy indices, inbreeding-endogamy (ie) indices, and frequencies of the genotype and allele frequencies of four DNA markers (17 alleles). The prevalences of hereditary diseases have been calculated for different population groups: urban and rural populations, Udmurts and other ethnic groups. These groups, especially the urban and rural populations, substantially differed from one another in the prevalences of autosomal dominant (AD) and autosomal recessive (AR) diseases. The correlation between the prevalence of AD and AR diseases and the ie index is positive and significant. The spectrum of hereditary diseases detected in six districts of Udmurtia comprises 149 diseases (80, 57, and 12 AD, AR, and X-linked diseases, respectively). Accumulation of individual diseases in districts of Udmurtia and accumulation of diseases in Udmurtia as compared to regions studied earlier has been found. Cluster analysis of the frequencies of genes of AD and AR diseases and DNA markers has determined the gene geographic position of Udmurts.     

Medical genetic study of the Rostov oblast population: Analysis of surname distribution in seven districts

Data on the surname frequency distribution in seven raions (districts) of the Rostov oblast (region) have been used to calculate random inbreeding varying from 0.000064 to 0.000186 in the Volgodonsk and Millerovo districts, respectively. Schematic surname landscapes have been constructed for six districts. The observed spectrum of frequent surnames is compared with that of the complete register of surnames in Russia.     

Genetic structure of the Udmurt population

Integrated study of the genetic structure of the Udmurt population with respect to different genetic systems has been performed. Data on the genes of genetic diseases, abiotic parameters analyzed by population statistic methods, and DNA polymorphism are summarized. The populations of six raions (districts) of Udmurt Republic (the Mozhga, Malaya Purga, Sharkan, Debesy, Igra, and Glazov raions) have been studied. The total population studied was 267,655 people (an urban population of 150,119 people and a rural population of 117,536 people), including 155,346 Udmurts. The population structure has been studied in six districts on the basis of the vital statistics, Crow's indices, Malecot's isolation by distance parameters, ethnically assortative marriage parameters, endogamy indices, inbreeding-endogamy (ie) indices, and frequencies of the genotype and allele frequencies of four DNA markers (17 alleles). The prevalences of hereditary diseases have been calculated for different population groups: urban and rural populations, Udmurts and other ethnic groups. These groups, especially the urban and rural populations, substantially differed from one another in the prevalences of autosomal dominant (AR) and autosomal recessive (AR) diseases. The correlation between the prevalence of AD and AR diseases and the ie index is positive and significant. The spectrum of hereditary diseases detected in six districts of Udmurtia comprises 149 diseases (80, 57, and 12 AD, AR, and X-linked diseases, respectively). Accumulation of individual diseases in districts of Udmurtia and accumulation of diseases in Udmurtia as compared to regions studied earlier has been found. Cluster analysis of the frequencies of genes of AD and AR diseases and DNA markers has determined the gene geographic position of Udmurts.     

Diversity in autosomal-dominant diseases in the Russian population

Results of 20-year studies on the diversity of autosomal dominant (AD) diseases are summarized. The studies were carried out in six regions of Russia: Kirov, Kostroma, and Bryansk oblasts; Krasnodar krai; and Adygea and Marii El republics. A total of 1.5 million subjects from 44 raions (districts) were studied. In the populations studied, 144 AD diseases were found; the total number of affected persons was 1723. The prevalence rate in the region where the disease was found and the average prevalence rate in the total population studied were calculated for each disease. Only 11 AD diseases had prevalence rates of 1:50,000 or higher. About half of AD diseases (64) had a very low prevalence rate (1:861,408). However, most cases (about 70% of the affected persons) were accounted for by more frequent diseases. Forty-six diseases exhibited local accumulation. The AD mutation rate was estimated by direct calculation. This rate was 0.542 x 10(-6) per gamete per generation.     

A medico-genetic description of inhabitants of two regions of the Kransnodar Krai]

The spectrum and prevalence rate of hereditary pathology in Kanevskii and Bryukhovetskii raions (districts) of Krasnodar krai (territory) were analyzed. The total size of the studied population was 145,937. The prevalence rate of monogenic hereditary pathology was estimated. This value was 1.08 +/- 0.08, 0.72 +/- 0.07, and 0.20 +/- 0.06 per 1000 people for autosomal dominant (AD), autosomal recessive (AR), and X-linked (XL) recessive diseases, respectively. Forty-two AD (158 affected persons in 82 families), 32 AR (105 affected persons in 82 families), and 6 XL disease entities (13 affected persons in 8 families) were found. A slight genetic subdivision was found in the populations of Kanevskii and Bryukhovetskii raions. However, it was not found to affect the prevalence of hereditary pathology.     

The gene pool of the Belgorod region population: I. Differentiation of all district populations based on anthroponymic data

The gene pool of the entire population of all the 21 raions (districts) of the Belgorod oblast (region) has been studied using anthroponymic data. Considerable geographic variations of the number of surnames and the degree of population subdivision (0.00003 < f(r)* < 0.00125) in the 21 districts have been demonstrated. Districts with low population subdivision levels are mainly located in the central and southwestern raions of the Belgorod oblast, contain an urbanized area (city), and border on Ukraine (they are characterized by a considerable Ukrainian immigration). Urbanization significantly affects the population structure of the Belgorod oblast. In urbanized districts, rural populations lack the relationships between the population size, number of surnames, and population subdivision level (f(r)).     

Genetic and demographic structure of Russian populations from the Tver' and Rostov regions

Based on the data from 569 questionnaires collected in Udomlya and Ostashkov raions of Tver oblast and 436 questionnaires collected in Tsimlyansk and Dubovsk raions of Rostov oblast, genetic demographic characteristics and Crow's index for urban and rural populations of these regions were calculated. The data obtained were compared with those for other Russian populations obtained earlier.     

Genetic and Demographic Structure of Russian Populations from Tver and Rostov Oblast

Based on the data from 569 questionnaires collected in Udomlya and Ostashkov raions of Tver oblast and 436 questionnaires collected in Tsimlyansk and Dubovsk raions of Rostov oblast, genetic demographic characteristics and Crow's index for urban and rural populations of these regions were calculated. The data obtained were compared with those for other Russian populations obtained earlier.     

The marriage migration characteristics of the Rostov oblast population

Marriage records have been used to study the marriage migration structure of five raions of the Rostov oblast. The mean ethnic marriage assortativeness in the Russian and Ukrainian rural populations are 1.16 and 1.6, respectively. The endogamy index of the urban population varies from 0.19 to 0.34; and that of the rural population, from 0.21 to 0.54. Malecot's isolation by distance parameters have been calculated. Genetic landscapes have been constructed.     

The gene pool of the Belgorod oblast population: Description of the “genetic landscape” of 22 district populations

Data on the frequencies of all (50412) surnames in a total population of 849399 people have been treated by various methods of multivariate statistics (cluster analysis, multidimensional scaling, and factor analysis) to show that 22 district populations of the Central Chernozem region of Russia form a definite, ordered system of population groups. All raions (administrative districts) of Belgorod oblast (administrative region) have been grouped into four clusters corresponding to the actual geographic locations of the populations. Districts of the eastern cluster are characterized by very specific spectrum and frequencies of surnames; districts of the western cluster differ in a high proportion of Ukrainian surnames     

Hereditary diseases of nervous system in the population of Vladimir province

The first population genetic study of hereditary disorders of the nervous system (HDNS) in Vladimir oblast was carried out. A total of 1,622,900 subjects, including 1,306,200 from the urban and 316,700 from the rural population, were tested. The population examined was characterized by virtually homogenous ethnic structure, with Russians constituting 95.76%. Pooled prevalence of HDNS in Vladimir oblast corresponded to the average prevalence for other Russian populations. Substantial differences between urban and rural populations in respect of the population load of HDNS and its nosological structure were not observed. A total of 22 nosological forms of HDNS were revealed, including thirteen autosomal dominant (193 families with 272 affected individuals), seven autosomal recessive (59 families with 66 affected individuals), and two X-linked (15 families with 17 affected individuals) diseases. The composition of the HDNS spectrum "nucleus" in Vladimir oblast displayed a number of differences from that in the majority of other populations examined. The HDNS in different regions of the area tested were characterized by different prevalence and spectrum. The data obtained may constitute a basis for regional registration of HDNS in Vladimir oblast.     

Prevalence of hereditary pathology in Altai Republic

Medical genetic study of the population of Altai Republic (Russia) has been performed. The population sample comprises 203 148 subjects, including 59 196 Altaians, 134 972 Russians, and 8980 Kazakhs. For each nosological group, the loads of Mendelian pathology with different modes of inheritance and their prevalence rates in urban and rural populations have been determined. Thirty-six autosomal dominant (AD) diseases have been found in a total of 121 subjects, with hereditary syndromes being the most prevalent. Autosomal recessive (AR) pathology is represented by 24 diseases found in 158 subjects, with metabolic disorders being the most prevalent; and X-linked pathology, by four diseases in nine subjects. The prevalence rate has been calculated for each nosological form in the district where it has been found. The loads of AD, AR, and X-linked pathologies in the urban population were, respectively, 2.98 and 9.62 per 1000 people and 0.56 per 1000 men in Altaians; 0.86 and 0.94 per 1000 people and 0.23 per 1000 men in Russians; 0.34 and 1.16 per 1000 people in Kazakhs. In the rural population, the genetic load has been calculated for each district. The spectrum of hereditary pathology in the populations studied is described.     

Integrated population genetic and medical genetic study of two raions of the Tver oblast

An integrated medical genetic an population genetic study has been performed in two raions (administrative districts) of the Tver oblast (region) of Russia: the Udomlya raion located in the zone affected by the Kalininskaya Nuclear Power Plant and the Ostashkov raion, which served as a control district. No significant differences has been found with respect to the genetic parameters studied. The values of these parameters in the populations of the town of Udomlya, the town of Ostashkov, the Udomlya raion, and the Ostashkov raion, respectively, are the following: random inbreeding, 0.00006, 0.00011, 0.000167, and 0.000366; endogamy index, 0.05, 0.43, 0.30, and 0.42; local inbreeding, 0.0003, 0.00045, 0.0009, and 0.0011; the degree of isolation by distance, 0.0003, 0.00045, 0.0009, and 0.0005; sigma, 2098, 1338, 1473, and 1189; the load of autosomal dominant (AD) diseases, 0.71, 0.92, 0.92, and 1.37; the load of autosomal recessive (AR) diseases, 0.68, 0.69, 0.67, and 0.82; and the load of X-linked diseases, 0.18, 0.64, 0.83, and 0.27.