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Biomedical subjects

E K Ginter

Publications and source records attributed to E K Ginter.

At least 19 recordsLinked to original sources

[Analysis of polymorphism at nine nuclear genome DNA loci in maris].

Population genetic survey of the indigenous populations of the Marii El Republic, represented by the two major ethnographic groups of Maris, Meadow (five samples from Morkinsk, Orshansk, Semursk, Sovetsk, and Zvenigovsk districts) and Mountain (one sample from Gornomariisk district) Maris, was carried out. All Mari groups were examined at nine polymorphic DNA loci of nuclear genome, VNTR(PAH) (N = 422), STR(PAH) (N = 152), VNTR(ApoB) (N= 294), VNTR(DAT1) (N = 363), VNTR(eNOS) (N = 373), ACE (N = 412), IVS6aGATT (N = 513), D7S23(KM.19) (N = 494), and D7S8 (N = 366). Allele and genotype frequency distribution patterns were obtained for individual samples and ethnographic groups, as well as for the ethnic group overall. In each of six Mari samples examined, the deficit of heterozygotes was observed, i.e., the mean observed heterozygosity was lower than the expected one. The indices of mean heterozygosity, Hs = 0.455, and interpopulation differentiation, FST = 0.0024, for the Mari gene pool were obtained using a set of DNA markers analyzed. Analysis of the genetic distances and between population differentiation (FST) showed that the main part of genetic diversity in Maris was determined by the differentiation between the populations of Meadow Maris. The contribution of the differences between the ethnographic groups of Mountain and Meadow Maris to the ethnic gene pool was small. It is suggested that the main role in the formation of the Mari gene pool is played by the geographic factor.

Alleles↗

New mutations in the APC gene in familial adenomatous polyposis: detection, characterization, and analysis.

The spectrum of mutations in the APC gene in familial adenomatous polyposis was detected in a sampling from the Russian population. Fifteen new mutations were found. Deletions associated with the loss of only 1 or 2 nucleotides (89% cases) prevailed among new (unique) mutations, while all known deletions were caused by the loss of 4 or 5 nucleotides. The detected differences in the deletion characteristics between unique and repeated mutations in the APC gene were typical of samples of patients from a number of populations. Samplings from different populations were heterogeneous by this sign. The incidence of 1-2-nucleotide deletions among unique and repeated deletions in the APC gene in patient samplings from different countries were in negative correlation.

Adenomatous Polyposis Coli↗

[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.

Consanguinity↗

Spectrum of mutations in BRCA1 gene in hereditary forms of breast and ovarian cancer in Russian families.

The 5382insC mutation predominated (94%) in the spectrum of detected mutations of BRCA1 gene. High incidence of this mutation in familial breast cancer detected for the first time attested to origination of 5382insC mutation from the European part of Russia. The percentage of families with mutations in BRCA1 gene and familial predisposition to ovarian cancer was significantly higher than in hereditary predisposition to breast cancer (p<0.007). These data suggest that clinical manifestation of the mutation depends on genotypical factors other than the position of this mutation in BRCA1 gene. The results prompt screening for hereditary predisposition to these diseases.

BRCA1 Protein↗

[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.

Demography↗

[Temporal dynamics of ethnic assortativeness in the Tsivil'sk region of Chuvashia].

Based on marriage records for 1950-1959, 1970-1979, and 1990-1999, ethnic assortativeness of Chuvash and Russian inhabitants of Tsivil'sk raion of the Chuvash Republic was calculated. It was shown that in half a century ethnic assortativeness of Chuvashes did not change (1.18, 1.15, and 1.15), while in Russians a clear downward trend was observed (4.20, 2.18, and 1.28). The data on ethnic assortativeness obtained were compared with those for the same populations from other regions of the Chuvashia examined earlier.

Ethnicity↗

[Prevalence and molecular-genetic typing of nonsyndromal neurosensory deafness in the Chuvash Republic].

Summarized genetic epidemiological characteristics of nonsyndromic sensorineural deafness in six raions of Chuvash Republic (Cheboksary, Kanash, Morgaushi, Tsivil'sk, Mariinski Posad, and Alatyr') are presented. A total of 264,419 individuals were examined. Forty-five families (60 affected individuals) with autosomal recessive (AR) and 8 families (18 affected individuals) with autosomal dominant (AD) nonsyndromic sensorineural deafness (NSSD) were identified. The load of AD and AR NSSD in the raions examined was estimated. A correlation between the distribution of AR NSSD and genetic drift was demonstrated. Furthermore, the load of AR NSSD was substantially higher in the regions with higher differentiation level. The Spearman's correlation coefficient value was 0.87. Typing of the 35delG mutation in the gene for connexion 26 was carried out in 34 patients from 26 families with AR NSSD. Comparative estimates of the NSSD prevalence in a number of Russian populations were performed.

Connexin 26↗

[Population-genetic structure of Chuvashia (from data on eight DNA loci in the nuclear genome)].

Population-genetic study of indigenous populations representing three ethnic Chuvash group: highland (Cheboksarsk and Morgaush district), lowland (Kanash district) and mid-lowland (Marposad district). Eight polymorphic DNA loci of the nuclear genome (VNTR/PAH, STR/PAH, VNTR/ApoB, VNTR/DAT1, APF, VNTR/eNOS, IVS6aGATT, and KM.19/PstI) were examined in the population of each district. For each of the four population, we estimated the allele and genotype frequency distributions at each polymorphic system, heterozygosities HS and between-population differences FST. In the combined Chuvash sample, HS = 0.464 and FST = 0.006. Loci VNTR(DAT) and VNTR(ApoB) showed highest between-population differentiation (0.009 < or = FST < or = 0.012), and loci IVS6aGATT, APF, VNTR/eNOS, and D7S23 (KM.19), lowest differentiation (0.001 < or = FST < or = 0.003). Analysis of genetic distances revealed somewhat higher genetic similarity between the Cheboksarsk and Morgaush populations belonging to the highland Chuvash group, whereas the highland Chuvash population from the Marposad district, which belong to the mid-lowland group, was more distant from the former populations.

Base Sequence↗

[Comparison of Chuvashs with Maris and Russians by vital statistics and the Crow index].

Genetic demographic characteristics were calculated for Chuvash and Russian inhabitants of the Republic of Chuvashia. The generation lengths were 27.09 and 26.4 years and the sibship sizes were 2.54 and 1.82 for Chuvashes and Russians, respectively. Crow's indices and their components were as follows: Im = 0.05, If = 0.31, and Itot = 0.37 for Chuvashes and Im = 0.03, If = 0.43, and Itot = 0.46 for Russians. The genetic demographic characteristics obtained were compared with those for Highland and Meadow Maris.

Demography↗

[Population genetic study of the Alatyr region of the Republic of Chuvashiia].

Population genetic characteristics were estimated in the Alatyr' raion (administrative district) of the Republic of Chuvashia, which has long been populated by three ethnic groups. The ethnic assortativeness values in the town of Alatyr' and the rural area of the district were 1.17 and 1.21, respectively, for Russians; 1.14 and 4.82, respectively, for Chuvashes; and 1.33 and 2.45, respectively, for Mordovians. Wright's statistics were as follows: Fst = 0.00358, Fit = 0.00178, and Fis = 0.00134. The migration indices were 0.0264 for Alatyr' and 0.0178 for the district. The endogamy indices for the total and the Russian populations of Alatyr' were 0.47 and 0.53, respectively. The parameters of isolation by distance were a = 0.000189 and b = 0.00959 for the urban and a = 0.000318 and b = 0.00919 for the rural area. Schemes of the genetic landscape were constructed. The influence of the polyethnic composition on the genetic structure of the population is discussed.

Emigration and Immigration↗

[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.

Genes, Dominant↗

[Characterization of the marriage structure and migration in Chuvash population].

Parameters of the marriage structure and migration were analyzed on the basis of marriage records in the Kanash, Cheboksary, and Morgaushi raions of the Chuvash Republic. Ethnic assortiveness was not detected in Chuvashes and was 4.16-18.05 in Russians. Gene flow between Chuvashes and Russians was 5.1-8.3%; the degree of endogamy was 0.61-0.70.

Adult↗

[Malecot's parameters of isolation by distance and the degrees of endogamy in three regions of the Chuvash Republic].

Malecot's parameters of isolation by distance and the degree of endogamy were estimated for individual Village Soviets of the Kanash, Cheboksary, and Morgaushi raions of Chuvashiya. Inbreeding landscape schemes were constructed for the Kanash and Morgaushi raions. The suitability of the Malecot's model of isolation by distance for populations of the Village-Soviet level was analyzed.

Consanguinity↗

[Genetic epidemiological study of populations in three regions of Chuvashia Republic].

Comprehensive population genetic and medical genetic studies were performed in three raions (districts) of Chuvashia. The population of these districts is more than 90% Chuvash. About 70% of the families that completed reproduction had two or three children. The proportion of families with four or more children was 18%. The duration of generation was 27.6 years. The differential fertility and differential mortality indices in the Chuvash population were estimated at 0.33 and 0.076, respectively. The total index of differential selection was 0.403, which is typical of modern urbanized populations. Mean values of local inbreeding calculated from Malecot's model of isolation by distance were 0.00124 and 0.00377 for the urban and rural populations, respectively, of the districts studied. The prevalence rates of autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases were found to be 0.47, 0.52, and 0.35 per 1000, respectively, in the urban population and 1.62, 1.14, and 0.31 per 1000, respectively, in the rural population. Significant correlation between the local inbreeding and prevalence rates 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 populations.

Adolescent↗

[Autosomal-dominant osteopetrosis in Chuvashiya].

A genetic epidemiological study of osteopetrosis was carried out in Chuvashiya. The major signs of this disorder are severe anemia developed in the prenatal or early postnatal life, hepatosplenomegaly, and a progressive loss of sight and hearing. Osteopetrosis showed the autosomal recessive inheritance with a somewhat increased proportion of affected patients in families. The lowest estimate of osteopetrosis frequency in Chuvashiya was 0.00026, one affected patient per 3879 newborns. The osteopetrosis gene occurred at a frequency of 0.016; the proportion of heterozygotes was 3.15%. The gene was shown to be evenly distributed throughout the republic.

Genes, Recessive↗

[Analysis of diversity of autosomal-recessive diseases in Russian populations].

The diversity of autosomal recessive (AR) diseases was studied in six Russian regions: the Kirov, Kostroma, and Bryansk oblasts; Adygea Republic; Krasnodar krai, and Marii El Republic (in the latter region, the Mari and Russian ethnic groups were studied separately). In total, more than 1.5 million people were studied. The spectrum of the AR diseases included 101 nosological forms; the total number of the affected subjects was 942. For all diseases, the prevalence rate in the region where they were found and the mean prevalence rate in the total population studied were calculated. Only seven AR diseases had prevalence rates of 1:50,000 or higher; however, this group contained about 50% of the patients. About half of the AR diseases (66) had an extremely low prevalence rate (1:877,483). Eleven diseases exhibit local accumulation. Accumulation of some or other diseases was only observed in four out of seven populations studied (Marii El, Adygea, and the Kirov and Bryansk oblasts). To determine the cause of the local accumulation of some diseases in populations, correlation analysis of the dependence of accumulation of hereditary diseases on the genetic structure of the populations studied was performed. The accumulation coefficients for AR and autosomal dominant (AD) diseases and the mean values of random inbreeding (Fst) in individual districts were calculated for all populations studied. The coefficients of the Spearman rank correlation between the accumulation coefficient and random inbreeding (Fst) were 0.68 and 0.86 for the AD and AR diseases, respectively. The correlation between the accumulation of AD and AR diseases was 0.86. The relationships found indicate that the diversity of AD and AR diseases, as well as the genetic load, distinctly depended on the population genetic structure and were largely determined by genetic drift.

Genes, Recessive↗

[Population genetics and medicine].

The paper covers several topics that demonstrate a close relationship between population genetics and medicine. To study isolated populations is an effective tool to detect "new" Mendelian diseases and to map the genes of hereditary diseases. Several new molecular genetic techniques have been developed, which facilitates the procedure of gene mapping. New genetic polymorphisms, such as VNTR, STR, and SNP in particular, have increased the feasibility of searching for genes, which predisposes to common diseases through linkage mapping and association studies. DNA polymorphisms have been shown to be also effective in solving the problems of pharmacological genetics and for detecting genes whose variability is associated with the efficacy of drugs and their side effects.

Chromosome Mapping↗