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PubMed1990

[Nosogeography of hereditary and exogenous diseases of the nervous system among the populations of the territories in the upper Zaravshan river].

Medico-genetic, populational-genetic and clinico-genetic investigations were performed in upper Zeravshan river communities with population of 53,000. The investigation discovered a nonuniform nosologic spectrum of hereditary nervous diseases comprising a total of about 30 forms. An even distribution of hereditary diseases was found with a several degree of local accumulation of such forms as congenital femur dislocation, and surdomutism. Localities with especially high contents of ore deposits and increased underground water mineralization had higher incidence of severe hereditary disorders. Inbreeding and little migration were the major factors promoting the spread of hereditary disorders. Inbreeding coefficients was 0.0127 in the whole population with prevalence of cousin sibs wedlocks. The data allow one to create the regional registers of hereditary disorders taking into account the peculiarities of the population, and provide a more effective medico-genetic assistance to the region.

Adolescent↗
PubMed1990

Patterned selection of mates in St. Ouen, Jersey, and the Scilly Isles examined by isonymy.

Within-lineage repeated-pair isonymy is calculated as RPW = sigma [Sij(Sij - 1)]/sigma [Si(Si - 1)], in which Sij is the number of a combination of two surnames in marriages (for total RPW, in both orders, brides first and also grooms first) and Si is the corresponding number of individuals of each surname (for total RPW of both sexes). In St. Ouen the 3479 native Jersey marriages between 1634 and 1914 yield a mean total RPW of 0.03314, which can be compared with a random isonymy (Ir) of 0.02205 and a marital isonymy (Im) of 0.04942. In the most recent time periods (1830-1914) there was an increase in RPW, but the increase is small if all marriages are considered rather than only native Jersey ones. In the Scilly Isles 2827 marriages between 1725 and 1975 yield a mean total RPW of 0.05127, which compares with a mean Ir of 0.01960 and an Im of 0.05238. In each kind of isonymy there is a decline over 1850-1975 caused by increased migration to the Scilly Isles. In the Scilly Isles RPW consistently approximately equals Im, so the nonrandom component of inbreeding is fully accounted for by factors that affect marital choice in the whole lineage. In St. Ouen, however, RPW is intermediate in value between Ir and Im, so the nonrandom component of inbreeding is only partly a lineage phenomenon and is also affected by other (individual) factors in choice of spouses.

Channel Islands↗
PubMed1990

Temporal trends in marital structure and isonymy in S. Paolo Albanese, Italy.

In the fifteenth century, after the Turkish conquest of the Balkan area, Albanian communities migrated to Southern Italy. I investigated temporal trends in isolation from 1820 to 1982 in one of these communities, the population of S. Paolo Albanese, Basilicata, which still uses the original language and religious rites. Marital structure is characterized by a high average frequency of village endogamy (75.2%). Among the exogamous marriages there is a preference for mates from Italo-Albanian settlements, with higher values in the 1800s. The distribution of marital distances reflects the positive assortative mating by ethnic community. The mean frequency of isonymous marriages was 9.01% from 1820 to 1982. These results indicate that total inbreeding from isonymy is a reliable indicator of isolation, showing temporal trends related to changes in endogamy. Fr accounts for the greater percentage of Ft in relation to the small population size and regularly decreases with time. The breakdown of isolation, as documented by the decrease in population size, endogamy, and inbreeding, is a recent feature (since 1960).

Albania↗
PubMed1979

[Correlation of heredity and environmental factors in the etiology of Vilyui encephalomyelitis. II. A population genetic study in districts of Vilyui encephalomyelitis distribution].

Population-genetic investigation was carried out in the regions endemic for Viljuisk encephalomyelitis (VE). The following indices were estimated: the relationship coefficient, the inbreeding coefficient, the intensity of migration, genetic structure of the population. The aim of the investigation was to explain causes of intrapopulational and, in some cases, of intragenus accumulation of the VE patients. No evidence of isolation or increased inbreeding were found in highly affected populations. The genetic structure of a group of VE patients tested for 9 polymorphic systems did not reveal any deviation from the control group. Several VE cases in healthy populations occured in some years after the immigration of a VE patient. These data confirm the hypothesis that VE is transmitted from a VE patient to healthy persons. Among these persons fall ill those who have a hereditary determined increased sensitivity to VE which results in intrapopulation and intragenus accumulation of VE cases.

Adult↗
PubMed1987

[Determination of the number of tissue compatibility genes in the carp using the transplantation test in the third generation of induced gynogenesis].

Transplantations have been carried out of anal fin in carp individual progeny of the third consecutive generation of induced gynogenesis. The part of grafts accepted made 19.4 +/- 5.0% (71 transplantations have been carried out). With the data obtained, an approximate quantity of histocompatible genes has been determined in carp which amounted to 32. Calculation has been done on the basis of the assumption that the part of histocompatible genes being in homozygous state in the given progeny equals the inbreeding coefficient of this progeny. Inbreeding coefficients have been calculated using experimental data of other authors.

Animals↗
PubMed1988

The equivalence of two tests and models for HLA data with no observed double blanks.

Gart and Nam (1984, Biometrics 40, 887-894) consider the analysis of an ABO-like model based on the Hardy-Weinberg law in the commonly occurring case of human leukocyte antigen (HLA) data where there are no double blanks, that is, no recessive homozygotes. They derive a score test, based on the truncated likelihood, of the hypothesis that the true recessive gene (or allele) frequency is zero. Yasuda (1968, Biometrics 24, 915-935) considers a similar codominant system wherein the true recessive gene frequency is assumed zero, but the Hardy-Weinberg law does not hold. In particular, he considers the possibility of a nonzero inbreeding coefficient. We show that the two models are equivalent; each likelihood can be shown to be a reparameterization of the other. Furthermore, the score test of the zero gene frequency in Gart and Nam is identical to the score test for a zero inbreeding coefficient given by Yasuda. The results are applied to an example wherein it appears that the Hardy-Weinberg model is appropriate. Thus, it is not possible in this population to identify homozygous individuals without error from phenotypic data alone.

Consanguinity↗
PubMed1986

Haemophilus influenzae type b disease in an Amish population: studies of the effects of genetic factors, immunization, and rifampin prophylaxis on the course of an outbreak.

In 1982, an outbreak of Haemophilus influenzae type b disease occurred in a 379-member Amish community. In an attempt to control the outbreak after the occurrence of the second case of disease, we investigated the combination of (1) rifampin chemoprophylaxis of all carriers of H influenzae type b and their household contacts from 1 month to 5 years of age and (2) H influenzae type b polysaccharide vaccine immunoprophylaxis of all community members 12 months of age and older. Despite our intervention, two additional cases of bacteremic H influenzae type b disease occurred in the ensuing 5 months, one in a 22-month-old infant who had been immunized at 19 months of age and the other in a child who had not been immunized because she was younger than 12 months of age. The outbreak ended following rifampin prophylaxis of all community members younger than 15 years of age. All of the children with disease were genetically related to one another, and three of the four were inbred. However, analysis of their coancestry revealed that neither the average level of kinship nor the average inbreeding level of the affected children differed significantly from those of the other children in the community. Furthermore, none of the four children with disease shared a human leukocyte antigen haplotype. Our observations suggest that inbreeding was not a risk factor in this community.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Frequency of polymorphisms for alleles encoding for liver proteins of domesticated mice.

Three different inbred strains of mice have been crossed with a lethal albino line (cch/c3H) and the liver polypeptides of the parents and offspring examined by two-dimensional polyacrylamide gel electrophoresis for evidences of protein polymorphisms, different alleles of which have gone to fixation in different strains. In the battery of polypeptides considered most favorable for scoring, 3.3 +/- 1.6 percent of the battery exhibited paired variants and 1.6 +/- 1.2 percent, unpaired. An adjustment for the fact the same allele of a biallelic polymorphism may go to fixation in two inbred lines of common ancestry leads to the suggestion that in the stock from which these inbred lines were ultimately derived, there were some 11.0 percent paired and 5.3 percent unpaired polymorphisms in the average mouse. This is about half the frequency of polymorphisms observed in wild European Mus musculus musculus and Mus musculus domesticus with one-dimensional electrophoresis of blood plasma and erythrocyte proteins. Three explanations were considered for the lower estimated frequency for liver protein polymorphisms: the difference is real, the apparent difference is due to the lower resolving power of two-dimensional gels, or the mouse strains from which the present inbred lines were drawn had already, lost through inbreeding, a considerable amount of their genetic variation before the inbreeding leading to the present strains commenced.

Alleles↗
PubMed1983

[Medical genetic study of the population or Turkmenia. II. The population structure of the inhabitants of the rural soviet Izgant, Geok-Tepe District, Ashkhabad Province].

This report is devoted to the populational description of the Ashkhabad district. Examination of one of the typical agricultural villages (Izgant of the Ashkhabad district) gave the main parameters of the population. The total number of the inhabitants studied is 1596, the proportion of the studied is 56%, the average family size for the parent with completed reproduction period being 5.47, the average generation time - 33 to 38, the gametic index - 0.67 and the inbreeding coefficient - 0.002267. The distribution of some markers (ABO, MN, Hp, Rh, Pp) have been studied. A rather low coefficient of inbreeding, as a result of the absence of geographical isolation, may account for incidence of autosomal recessive disorders.

Adolescent↗
PubMed1983

[Population genetics of the inhabitants of the European northern RSFSR. VI. The dynamics of the genetic load].

The dynamics of the lethal equivalents in two rural populations of Archangelsk regions during the periods from 1930 to 1953 and from 1954 to 1970 was investigated. The outcomes of 1617 pregnancies for 500 couples were analysed. The coefficient of inbreeding varied fo these couples from 0.001 to 0.08. For computing the genetic load, we followed the the methodology suggested by Morton, Crow and Muller in S. Smith's modification. The importance of comprehensive determination of inbreeding coefficient for reliable estimation of the genetic load was demonstrated. By comparing the two groups, it was shown that the coefficient B diminished approximately twice and the B/A ratio increased in both populations also by the factor of two. It is supposed that the diminishing of the number of lethal equivalents can be explained by a decrease in natural selection pressure. It is also supposed, that the segregational load is more sensitive to the decrease in natural selection pressure.'

Consanguinity↗
PubMed1984

Bardet-Biedl syndrome and retinitis punctata albescens in an isolated northern Canadian community.

Autosomal recessive inheritance of various conditions is well documented among inbreeding groups. In northern Canada inbreeding occurs in communities as a result of language and cultural uniqueness as well as geographic isolation. In one such community--Rae, in the Northwest Territories--two autosomal recessive disorders, the Bardet-Biedl syndrome and retinitis punctata albescens, are segregating. This report outlines the major clinical features of the disorders, establishes for both conditions the high frequency of the heterozygous carrier genotype in the community and suggests a possible way to reduce the likelihood of increased numbers of affected individuals in forthcoming generations.

Adolescent↗
PubMed1980

Isonymy in two Punjabi isolates of India.

Inbreeding coefficients and effective migrants for the immigrant Punjabi Khattri and Arora of Delhi were estimated from isonymous marriages by five methods: sigma qm2, sigma qf2, sigma qm qf, sigma qm2+f and sigma Ie (pair). It was found that the method sigma qmqf gives better estimates as expected by the isonymy method -- sigma Ie (Pair). A higher estimate of the random inbreeding coefficient suggests that Arora is more inbred than Khattri. The lesser number of effective migrants observed for Aroras also points to their relatively isolated nature. The two groups however, behave as one broad endogamous-panmictic unit.

Consanguinity↗
PubMed1981

The derivation of an inbred line of rats which develop asthma-like symptoms following challenge with aerosolized antigen.

Sensitized Sprague-Dawley rats developed respiratory impairment after challenge with aerosolized antigen. The response to challenge was heterogeneous. A proportion of each group of rats developed dyspnea and other symptoms similar to asthma; the remainder developed apnea but no other symptoms. Selective breeding from rats which developed dyspnea increased the incidence from 44% in F0 to 55% in F1 and greater than 90% in F2 and F3. Inbreeding also produced a significant increase in the duration of antigen-induced dyspnea. The results from the selective inbreeding suggest antigen-induced dyspnea is controlled genetically, possibly by multiple gene loci. These inbred rats constitute a population which have a predictable response to aerosolized antigen challenge. They should have utility in investigating allergic asthma and evaluating potential new drugs.

Aerosols↗
PubMed1995

[Genetic-demographic study of mountain populations of Daghestan and migrants from it to the lowlands. Study of genetic and marital structure].

The results of a genetic and demographic study of two "split" isolates of small native ethnic groups of Daghestan are described. Parts of these populations were resettled from habitual highland ecological conditions to radically new lowland conditions in the 1940s. These split isolates were compared with a population of native inhabitants of the Daghestan lowland. It was found that, since resettling, separated populations originating from split isolates became significantly different in both marriage and genetic structures. This is manifested in different phenotypic and allelic frequencies of a number of physiological and biochemical markers and in levels of their heterozygosity. To explain the differences revealed, a hypothesis was proposed about the relationship between levels of inbreeding, heterozygosity, and physiologic sensitivity that account for the differential adaptability of members of the isolated populations to changing environmental conditions. This is the first report of a series of papers describing the experimental testing of this hypothesis. While testing the validity of the hypothesis in this study, a positive linear correlation was found between inbreeding and homozygosity levels.

Consanguinity↗
PubMed1994

Religious differentials in postfamine marriage patterns, Northern Ireland, 1840-1915. I. Demographic and isonymy analysis.

During the Irish famine of 1846-1851 there were an estimated 1.0 million excess deaths, the migration of 1.3 million persons, and 300,000 averted births. To assess the influence of population changes at the local level in Ulster, decennial census records were analyzed for the Barony of Upper Ards, County Down, from 1841 to 1911. Data on marriages contracted in the four Roman Catholic, five Presbyterian, and eight Episcopalian congregations also were abstracted from civil parish registers for the period 1840-1915 and were used to calculate levels of random and nonrandom inbreeding through time by isonymy analysis. In the prefamine census of 1841 the total population of the Upper Ards was 16,964. From 1841 to 1911 population numbers decreased by 44.5%, with a consistent surplus of females in all parishes throughout the study period. Both population density and the number of persons per dwelling declined at equivalent rates, resulting in increasingly dispersed patterns of settlement. There was a marked overall increase in nonrandom inbreeding (Fn) in the immediate postfamine period, which was sustained throughout the nineteenth century before declining during 1900-1915. However, significant heterogeneity was observed in the Fn values calculated, both between and within each of the three main religious denominations, indicating differential local responses to marriage partner choice in the postfamine years. The observed changes are not compatible with a simple model of reduction in mate availability under conditions of population decline. Instead, they can most convincingly be explained in terms of a specific population response to the subsistence crisis initiated by the famine.

Consanguinity↗
PubMed1993

[Load of autosomal recessive diseases in populations of Kirov Province and its relationship to consanguinity].

The dependence of the load of autosomal recessive disorders on a variation of random inbreeding in the populations of the 9th Districts of the Kirov Province was investigated. The values of the Fst varied between different districts from 0.00021 to 0.0011 and the values of load of AR--from 0.73 to 2.01 affected per 1000. There is a close significant correlation (r = 0.90) between the parameters in the population studied which increased under analysis of the population considering the coefficients of random inbreeding.

Consanguinity↗
PubMed1993

[Dependence of the load of hereditary diseases on the level of endogamy of the Russian population].

Relationship between the index of endogamy and a random component of inbreeding in Russian populations was studied. It was shown that significant correlation (r = 0.74 +/- 0.24) exists between these parameters. Correlation coefficient between the index of endogamy and the load of autosome recessive pathology makes up 0.98 + 0.11. It is suggested that the index of endogamy could be used as a quantitative measure of genetic structure of the population where it is not possible to receive the inbreeding value using the routine methods.

Consanguinity↗
PubMed1996

Variability of genetic markers in Himachal Pradesh, India: variation among the subpopulations.

The genetic composition of one tribal and two nontribal populations of the Chamba District, Himachal Pradesh, India, was studied by phenotype analyses of 25 genetic markers (9 blood groups, 13 red cell enzymes, and 3 serum proteins). Furthermore, the genetic structure of 11 populations from 3 districts, Chamba, Kangra, and Kinnaur of Himachal Pradesh, was also analyzed using data from 20 loci (57 alleles). Nine genetic systems (ABO, Rh, FY, P, PGM, ACP, AK, PGD, and HP) showed highly significant heterogeneity in the five populations of Kinnaur District, whereas among the six populations from Chamba and Kangra districts the genetic variation was low. The FIS value at each locus for the five populations of Kinnaur District and the six populations from Chambra and Kangra districts was consistently higher than the FST estimates, suggesting that the population structure of both regions is influenced by local random inbreeding. Although the role of selection in local genetic differentiation cannot be ruled out, the present analyses indicate that local differentiation is mainly affected by geographic proximity, random inbreeding, and admixture.

Ethnicity↗