RESUMO
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ'≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02). Admixture estimates obtained by a maximum likelihood method using HLA-A/-B/-DRB1 as genetic estimators revealed that the main genetic components in Mexico as a whole are Native American (ranging from 37.8% in the northern part of the country to 81.5% in the southeastern region) and European (ranging from 11.5% in the southeast to 62.6% in northern Mexico). African admixture ranged from 0.0 to 12.7% not following any specific pattern. We were able to detect three major immunogenetic clusters correlating with genetic diversity and differential admixture within Mexico: North, Central and Southeast, which is in accordance with previous reports using genome-wide data. Our findings provide insights into the population immunogenetic substructure of the whole country and add to the knowledge of mixed ancestry Latin American population genetics, important for disease association studies, detection of demographic signatures on population variation and improved allocation of public health resources.
Assuntos
Alelos , Genética Populacional/métodos , Antígenos HLA/genética , Complexo Principal de Histocompatibilidade/genética , Polimorfismo de Nucleotídeo Único , DNA/genética , DNA/isolamento & purificação , Frequência do Gene , Genoma Humano , Haplótipos , Humanos , Desequilíbrio de Ligação , MéxicoRESUMO
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 144 Mexicans from the state of Guerrero to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes in the state of Guerrero include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Guerrero are Native American (61.36⯱â¯2.69% by ML; 54.17% of Native American haplotypes) and European (35.01⯱â¯4.59% by ML; 32.29% of European haplotypes), and a relatively low African genetic component (3.63⯱â¯2.38% by ML; 5.90% of African haplotypes).
Assuntos
Etnicidade/genética , Variação Genética , Genética Populacional , Antígenos HLA/genética , Alelos , Frequência do Gene , Genótipo , Geografia , Haplótipos , Humanos , Desequilíbrio de Ligação , MéxicoRESUMO
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 173 Mexicans from the state of Chiapas living in the city of Tuxtla Gutiérrez (Nâ¯=â¯52) and rural communities (Nâ¯=â¯121), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in Chiapas include 12 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Chiapas are Native American (71.61⯱â¯0.58% by ML; 53.16% of Native American haplotypes) and European (26.39⯱â¯5.05% by ML; 25.86% of European haplotypes), and a less prominent African genetic component (2.00⯱â¯5.20% by ML; 9.77% of African haplotypes).
Assuntos
Etnicidade/genética , Variação Genética , Genética Populacional , Antígenos HLA/genética , Alelos , Cidades , Frequência do Gene , Geografia , Haplótipos , Humanos , Desequilíbrio de Ligação , México , População RuralRESUMO
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 122 Mexicans from the state of Hidalgo living in the city of Pachuca (Nâ¯=â¯41) and rural communities (Nâ¯=â¯81), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in Hidalgo include eight Native American and one European haplotypes. Admixture estimates revealed that the main genetic components in Hidalgo are Native American (58.93⯱â¯2.16% by ML; 54.51% of Native American haplotypes) and European (32.49⯱â¯2.88% by ML; 28.69% of European haplotypes), and a relatively high African genetic component (8.58⯱â¯0.93% by ML; 6.97% of African haplotypes).
Assuntos
Etnicidade/genética , Variação Genética , Genética Populacional , Antígenos HLA/genética , Alelos , Frequência do Gene , Genótipo , Geografia , Humanos , Desequilíbrio de Ligação , México , População RuralRESUMO
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 88 Mexicans from the state of Querétaro living in the city of Querétaro (Nâ¯=â¯45) and rural communities (Nâ¯=â¯43), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Querétaro include seven Native American, two European and one Asian haplotype. Admixture estimates revealed that the main genetic components in the state of Querétaro are Native American (51.82⯱â¯4.42% by ML; 42.61% of Native American haplotypes) and European (48.18⯱â¯3.55% by ML; 46.02% of European haplotypes), with a virtually absent African genetic component (0.00⯱â¯4.25% by ML; 4.55% of African haplotypes).
Assuntos
Etnicidade/genética , Variação Genética , Genética Populacional , Antígenos HLA/genética , Alelos , Frequência do Gene , Genótipo , Geografia , Haplótipos , Humanos , Desequilíbrio de Ligação , México , População RuralRESUMO
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1217 Mexicans from the Mexico City Metropolitan Area living in the northern (Nâ¯=â¯751), southern (Nâ¯=â¯52), eastern (Nâ¯=â¯79), western (Nâ¯=â¯33), and central (Nâ¯=â¯152) Mexico City, and rural communities (Nâ¯=â¯150), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes include 11 Native American haplotypes. Admixture estimates revealed that the main genetic components are Native American (63.85⯱â¯1.55% by ML; 57.19% of Native American haplotypes) and European (28.53⯱â¯3.13% by ML; 28.40% of European haplotypes), and a less apparent African genetic component (7.61⯱â¯1.96% by ML; 7.17% of African haplotypes).
Assuntos
Etnicidade/genética , Variação Genética , Genética Populacional , Antígenos HLA/genética , Alelos , Cidades , Frequência do Gene , Geografia , Haplótipos , Humanos , Desequilíbrio de Ligação , México , População RuralRESUMO
OBJECTIVE: Hypersensitivity pneumonitis (HP) is an immunological disorder caused by antigen exposure in susceptible individuals. The PDCD1 polymorphisms, PD1.3 and PD1.5 have been associated with the susceptibility to inflammatory disorders. This study was conducted to test whether the PD1.3 and PD1.5 polymorphisms are associated with HP in Mexican patients and to explore the distribution of these polymorphisms in different Mexican ethnic groups. DESIGN AND METHODS: We studied 98 Mexican patients with HP and 92 healthy Mexican controls. Also, 156 healthy Amerindian individuals from two ethnic groups were included (96 Mayans and 60 Mayos). Polymorphisms were determined by TaqMan 5' nuclease assays. RESULTS: Significant differences in the distribution of the PD1.3 and PD1.5 genotypes between HP patients and healthy Mestizo controls were not found. We observed a significantly different distribution of these polymorphisms in Mexican Mestizos when compared to the Amerindians. CONCLUSIONS: We found no association between PD1 polymorphism and HP; however the distribution of these polymorphisms was different in Mexican Mestizos and Amerindians.
Assuntos
Alveolite Alérgica Extrínseca/genética , Antígenos CD/genética , Proteínas Reguladoras de Apoptose/genética , Etnicidade/genética , Predisposição Genética para Doença/genética , Polimorfismo Genético/genética , Adulto , Alveolite Alérgica Extrínseca/imunologia , Feminino , Marcadores Genéticos/genética , Genótipo , Humanos , Masculino , México/etnologia , Repetições de Microssatélites/genética , Receptor de Morte Celular Programada 1RESUMO
Las espondiloartropatías seronegativas (EaSN) son padecimientos reumatológicos con etiopatogenia y cuadro clínico heterogéneos; sin embargo, tienen varias características comunes como asociación a uveítis anterior, enfermedad inflamatoria intestinal, uretritis, cervicitis, antecedentes de diarrea aguda en el mes anterior a la presentación de la artritis, inflamación de las articulaciones sacroiliacas, marcada agregación familiar, prevalencia alta del antígeno HLA-B27 y factor reumatoide negativo El espectro clínico de las EaSN varía dependiendo del área geográfica, el grupo étnico, la edad del paciente y la exposición a bacterias llamadas artritogénicas. Para explicar la fisiopatología de estos padecimientos se han propuesto diversos mecanismos que involucran factores genéticos y ambientales. Entre los primeros encontramos algunos subtipos del antígeno HLA-B27 (HLA-B*2701, *2702, *2703, *2704, *2705, *2707 y *271 0) y su interacción con factores ambientales como antígenos de bacterias artritogénicas como Chlamydia trachomatis, Yersinia enterocolitica, Salmonella typhimurium y Shigella flexneri, que podrían desencadenar una respuesta autoinmune; además, hay otros genes del complejo principal de histocompatibilidad implicados como HLA-B39, MICA y MICB, TAP, LMP2 y LMP7 y el complotipo FC31.
