RESUMO
Gallbladder disease is a common source of morbidity in the Mexican American population. Genetic heritage has been proposed as a possible contributor, but evidence for this is limited. Because gallbladder disease has been associated with Native American heritage, genetic admixture may serve as a useful proxy for genetic susceptibility to the disease in epidemiologic studies. The objective of our study was to examine the possibility that gallbladder disease is associated with greater Native American admixture in Mexican Americans. This study used data from the Hispanic Health and Nutrition Examination Survey and was based on 1,145 Mexican Americans who underwent gallbladder ultrasonography and provided usable phenotypic information. We used the GM and KM immunoglobulin antigen system to generate estimates of admixture proportions and compared these for individuals with and without gallbladder disease. Overall, the proportionate genetic contributions from European, Native American, and African ancestries in our sample were 0.575, 0.390, and 0.035, respectively. Admixture proportions did not differ between cases and noncases: Estimates of Native American admixture for the two groups were 0.359 and 0.396, respectively, but confidence intervals for estimates overlapped. This study found no evidence for the hypothesis that greater Native American admixture proportion is associated with higher prevalence of gallbladder disease in Mexican Americans. Reasons for the finding that Native American admixture proportions did not differ between cases and noncases are discussed. Improving our understanding of the measurement, use, and limitations of genetic admixture may increase its usefulness as an epidemiologic tool as well as its potential for contributing to our understanding of disease distributions across populations.
Assuntos
Doenças da Vesícula Biliar/genética , Genética Populacional , Hispânico ou Latino/genética , Indígenas Norte-Americanos/genética , Adulto , Idoso , Feminino , Doenças da Vesícula Biliar/epidemiologia , Doenças da Vesícula Biliar/etnologia , Predisposição Genética para Doença , Humanos , Imunoglobulinas/análise , Imunoglobulinas/imunologia , Masculino , Pessoa de Meia-Idade , PrevalênciaRESUMO
Using an isoelectric focusing gel containing agarose, urea, a separator and a narrow range ampholyte of pH 5-6, a system was designed to split the F13A*1 and F13A*2 alleles into the subtypes 1A, 1B, 2A and 2B. Four population groups (European-Americans, African-Americans, Mexican-Americans and Native-Americans) were data based. Subtyping F13A increased the information content significantly over the previous F13A typing system by doubling the number of alleles and increasing the number of phenotypes from three to ten. The new system has proved to be of value in parentage testing by increasing exclusionary power in cases of non-paternity and increasing the paternity index in non-exclusionary cases. Though there does not appear to be any significant variation among U.S. populations, published data on Japanese populations suggests that significant differences among populations may exist, leading to an anthropological usefulness as well.
Assuntos
Western Blotting/métodos , Eletroforese em Gel de Ágar/métodos , Fator XIII/classificação , Focalização Isoelétrica/métodos , Negro ou Afro-Americano , Alelos , Fator XIII/química , Fator XIII/genética , Frequência do Gene , Humanos , Indígenas Norte-Americanos , México , Fenótipo , População , População BrancaRESUMO
A quick, sensitive and economical technique has been developed to subtype GC and ESD simultaneously on the same agarose IEF gel. This method could be a useful tool for forensic application.
Assuntos
Carboxilesterase , Hidrolases de Éster Carboxílico/análise , Focalização Isoelétrica/métodos , Proteína de Ligação a Vitamina D/análise , Medicina Legal , Focalização Isoelétrica/economia , Sensibilidade e Especificidade , Sefarose , Fatores de TempoRESUMO
The sera of a sample of 204 Creoles from Trinidad were tested for the presence of polymorphic gene complexes occurring on immunoglobulin light- and heavy-chain molecules including the allotypic markers IGKC 1, IGHA2 1 and 2, IGHG1 A, X, F, and Z, and IGHG3 G, G5, B0, B1, B3, B4, B5, C3, C5, S, and T. Nine IGHG (GM) haplotypes occur in polymorphic frequencies (greater than .01) in this population, including known African, Asian, Caucasian, and Amerindian marker haplotypes. Significant differences (P less than .01) were found in the frequency distributions of three IGHG (GM) haplotypes and the frequency of IGKC*1 in these data and data from Creole populations of Belize and St. Vincent. The Creoles of Trinidad and St. Vincent are more similar in IGHG (GM) haplotype distributions than are Trinidad and Belize populations. Previous testing has revealed no significant differences between St. Vincent and Belize Creoles at the Ig allotypic loci. Analysis of migration patterns in the Caribbean suggests that different rates of Asian migration have maintained regional diversity at these loci, while continuous gene flow from the eastern Caribbean to Trinidad has had a relative homogenizing effect on the gene pools of this area.
Assuntos
Variação Genética , Alótipos de Imunoglobulina/genética , Distribuição de Qui-Quadrado , Haplótipos , Humanos , Fenótipo , Trinidad e TobagoRESUMO
The sera of a sample of 204 Creoles from Trinidad were tested for the presence of polmorphic gene complexes occurring on immunoglobulin light and heavy-chain molecules including the allotypic markers IGKC 1, IGHA2 1 and 2, IGHG1 A, X, F, and Z, and IGHG3 G, G5, B0, B1, B3, B4, B5, C3, C5, S, and T. Nine IGHG (GM) haplotypes occur in polymorphic frequencies (greater than .01) in this population, including known African, Asian, Caucasian, and Amerindian marker haplotypes. Significant differences (P less than .01) were found in the frequency distributions of three IGHI (GM) haplotypes and the frequency of IGKC*1 in these data and data from Creole populations of Belize and St. Vincent. The Creoles of Trinidad and St. Vincent are more similar in IGHG (GM) haplotype distributions than are Trinidad and Belize populations. Previous testing has revealed no significant differences between St. Vincent and Belize Creoles at the Ig allotypic loci. Analysis of migration patterns in the Caribbean suggests that different rates of Asian migration have maintained regional diversity at these loci, while continuous gene flow from the eastern Caribbean to Trinidad has had a relative homogenising effect on the gene pools of this area. (AU)
Assuntos
Humanos , Alótipos de Imunoglobulina/genética , Variação Genética , Distribuição de Qui-Quadrado , Haplótipos , Fenótipo , Trinidad e TobagoRESUMO
Because Alaskan Eskimos have the greatest known endemic risk of Haemophilus influenzae type b (Hib) disease and represent a comparatively homogeneous population, we selected this population to evaluate the presence or absence of an association of 35 genetic markers (alleles or allotypes) at 12 chromosomal loci with susceptibility to both invasive Hib disease risk and level of Hib anticapsular antibody. We studied nearly all Alaskan Eskimo children who had had invasive Hib disease between 1971 and 1982 in southwestern Alaska (n = 103) and an equivalent number of controls matched for age, race, and village of residence, and verified not to have had proved or suspected Hib disease. We found no significant associations with Hib disease for the single alleles of HLA-A, -B, -C, -DR, Gm, Km, Am, Kidd, MNSs, ABO, esterase D, or glutamate pyruvate transaminase loci. However, we observed a significant interaction of two loci, Gm(a;..;g,s,t) allotype and HLA-DR8 (P = 0.002), with increased Hib disease susceptibility, and an interaction of the same Gm allotype and HLA-DR5 with decreased disease susceptibility (P = 0.01). We also compared the level of anticapsular antibody to Hib with each genetic marker and two-locus interactions, but no genetic association with antibody level was found. We conclude that some genetic factors contribute to the susceptibility to invasive Hib disease in this population.
Assuntos
Infecções por Haemophilus/genética , Alaska , Anticorpos/análise , Pré-Escolar , Suscetibilidade a Doenças , Feminino , Antígenos HLA/genética , Haemophilus influenzae , Humanos , Lactente , Inuíte , Masculino , RiscoRESUMO
The distribution of Glm(f, z, a, and x), G3m(b0, b1, b3, b5, c3, c5, g, s, t and v), A2m(1 and 2) and Km(1) (formerly Inv(1)) allotypic determinants has been examined in specimens from the inhabitants of two transplanted Tlaxcaltecan villages (Cuanalan and Saltillo). The results indicate that Gmza;g Am1, Gmza;g Am2, Gmzax;g Am1, Gmza;bst Am1, Gmza;bst Am2, Gmf;b Am1, Gmza,b Am1, Gmza;b Am2 and Km1 are polymorphic or marginally polymorphic in both populations, while Gmza;bc3,5 Am2, Gmza;bs Am2, and Gmzax;g Am2 were detected only in Saltillo. Two related individuals from Saltillo have either a Gmf;g Am1 or Gmf;-Am1 haplotype while a third unrelated individual had either a Gmf;g Am1 or Gm-;g Am1 haplotype. The frequencies observed for "residents" of Cuanalan are similar to those for other Indian populations in Mexico. Estimation of Caucasian and African admixture within the two communities indicates significant heterogeneity among the inhabitants of Cuanalan, in that Tlaxcaltecan residents have no detectable African admixture and significantly less Caucasian admixture than recent immigrants, with Tlaxcaltecan-immigrant hybrids intermediate, while no significant variation was observed among the subdivisions of Saltillo. However, Saltillo has greater Caucasian and African admixture than Cuanalan. Admixture estimates based on Gm haplotypes appear to agree much better with known historical events than those generated by blood groups, indicating that Gm is a better estimator of admixture than blood groups under certain circumstances.