Search

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 461 Mexicans from the state of Chihuahua living in Chihuahua city (N = 119), Ciudad Juárez (N = 106) and rural communities (N = 236), to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We find that the most frequent haplotypes found in the state of Chihuahua include seven Native American and three European haplotypes. Admixture estimates revealed that the main genetic components in Chihuahua are European (52.12 ± 0.88% by ML; 41.53% of European haplotypes) and Native American (39.51 ± 2.17% by ML; 37.45% of Native American haplotypes), while African genetic component was less apparent (8.36 ± 1.47% by ML; 11.70% of African haplotypes).

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 (N = 751), southern (N = 52), eastern (N = 79), western (N = 33), and central (N = 152) Mexico City, and rural communities (N = 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 ± 1.55% by ML; 57.19% of Native American haplotypes) and European (28.53 ± 3.13% by ML; 28.40% of European haplotypes), and a less apparent African genetic component (7.61 ± 1.96% by ML; 7.17% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 498 Mexicans from the state of Michoacán living in the city of Morelia (N = 150) and rural communities (N = 348), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Michoacán include 12 Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Michoacán are Native American (48.79 ± 1.44%) and European (43.10 ± 0.86%), while African genetic component is less apparent (8.11 ± 0.85%). Our findings add to the growing knowledge on the population genetics of Western Mexico and provide new HLA data on populations from Michoacán.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 2046 Mexicans from the state of Jalisco living in the city of Guadalajara (N = 1189), Tlajomulco (N = 30), Tlaquepaque (N = 39), Tonalá (N = 35), Zapopan (N = 168) and rural communities (N = 585), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes found in the state of Jalisco include nine Native American most probable ancestry and three European haplotypes. Admixture estimates revealed that the main genetic components in the state of Jalisco are European (48.45 ± 1.18% by ML; 41.66% of European haplotypes) and Native American (44.02 ± 1.24% by ML; 39.86% of Native American haplotypes), while African genetic component is less apparent (7.53 ± 0.30% by ML; 9.62% of African haplotypes).

Here we studied HLA blocks and haplotypes in a group of 218 Lacandon Maya Native American using a high-resolution next generation sequencing (NGS) method. We assessed the genetic diversity of HLA class I and class II in this population, and determined the most probable ancestry of Lacandon Maya HLA class I and class II haplotypes. Importantly, this Native American group showed a high degree of both HLA homozygosity and linkage disequilibrium across the HLA region and also lower class II HLA allelic diversity than most previously reported populations (including other Native American groups). Distinctive alleles present in the Lacandon population include HLA-A*24:14 and HLA-B*40:08. Furthermore, in Lacandons we observed a high frequency of haplotypes containing the allele HLA-DRB1*04:11, a relatively frequent allele in comparison with other neighboring indigenous groups. The specific demographic history of the Lacandon population including inbreeding, as well as pathogen selection, may have elevated the frequencies of a small number of HLA class II alleles and DNA blocks. To assess the possible role of different selective pressures in determining Native American HLA diversity, we evaluated the relationship between genetic diversity at HLA-A, HLA-B and HLA-DRB1 and pathogen richness for a global dataset and for Native American populations alone. In keeping with previous studies of such relationships we included distance from Africa as a covariate. After correction for multiple comparisons we did not find any significant relationship between pathogen diversity and HLA genetic diversity (as measured by polymorphism information content) in either our global dataset or the Native American subset of the dataset. We found the expected negative relationship between genetic diversity and distance from Africa in the global dataset, but no relationship between HLA genetic diversity and distance from Africa when Native American populations were considered alone.

Pathogens and associated outbreaks of infectious disease exert selective pressure on human populations, and any changes in allele frequencies that result may be especially evident for genes involved in immunity. In this regard, the 1346-1353 Yersinia pestis-caused Black Death pandemic, with continued plague outbreaks spanning several hundred years, is one of the most devastating recorded in human history. To investigate the potential impact of Y. pestis on human immunity genes we extracted DNA from 36 plague victims buried in a mass grave in Ellwangen, Germany in the 16th century. We targeted 488 immune-related genes, including HLA, using a novel in-solution hybridization capture approach. In comparison with 50 modern native inhabitants of Ellwangen, we find differences in allele frequencies for variants of the innate immunity proteins Ficolin-2 and NLRP14 at sites involved in determining specificity. We also observed that HLA-DRB1*13 is more than twice as frequent in the modern population, whereas HLA-B alleles encoding an isoleucine at position 80 (I-80+), HLA C*06:02 and HLA-DPB1 alleles encoding histidine at position 9 are half as frequent in the modern population. Simulations show that natural selection has likely driven these allele frequency changes. Thus, our data suggests that allele frequencies of HLA genes involved in innate and adaptive immunity responsible for extracellular and intracellular responses to pathogenic bacteria, such as Y. pestis, could have been affected by the historical epidemics that occurred in Europe. - Introduction - Results -- Archaeological and Anthropological Findings -- The 16th Century Ellwangen Plague Victims Display Genetic Similarity with Modern Inhabitants -- Two Immunity-Related Genes Harbor Strongly Differentiated single nucleotide polymorphisms -- No Evidence for Role of CCR5-D32 in Protection from Y. pestis Infection Discussion -- Natural Selection Has Increased HLA-DRB*13 and Reduced HLA-B*51 and -C*06 Frequencies in Modern Individuals -- Higher Incidence of KIR3DL1 Interaction with HLA-B in Plague Victims Than Modern Inhabitants of Ellwangen - Discussion - Materials and Methods

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1011 Mexicans from the state of Tlaxcala residing in the city of Tlaxcala (N = 181) and rural communities (N = 830), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes in Tlaxcala are all of Native American origin. Admixture estimates revealed that the main genetic components are Native American (75.13 ± 1.56% by ML; 69.24% based on of Native American haplotypes) and European (16.10 ± 4.98% by ML; 19.74% of European haplotypes), with a less prominent African genetic component (8.78 ± 4.09% by ML; 4.35% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 95 Mexicans from the state of Aguascalientes to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We find that the most frequent haplotypes in the state of Aguascalientes include four Native American, three European and one Asian haplotypes. Admixture estimates revealed that the main genetic components in the state of Aguascalientes are Native American (54.53 ± 3.22% by ML; 44.21% of Native American haplotypes) and European (44.34 ± 0.45% by ML; 40.53% of European haplotypes), and a relatively low African genetic component (1.13 ± 2.33% by ML; 5.26% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 2827 Mexicans from the state of Puebla living in the city of Puebla (N = 1994) and rural communities (N = 833), to obtain information regarding allelic and haplotypic frequencies. We found that the 16 most frequent haplotypes in Puebla are all of them Native American. Admixture estimates revealed that the main genetic components in the state of Puebla are Native American (72.21 ± 1.25% by ML; 63.30% of Native American haplotypes) and European (21.05 ± 1.92% by ML; 23.86% of European haplotypes), and a less prominent African genetic component (6.74 ± 2.20% by ML; 6.20% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 81 Mexicans from the state of Campeche living in the city of Campeche (N = 34) and rural communities (N = 47), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Campeche include ten Native American, three European, one African and one Asian haplotype. Admixture estimates revealed that the main genetic components in the state of Campeche are Native American (65.56 ± 0.96% by ML; 51.24% of Native American haplotypes), European (34.44 ± 10.94% by ML; 30.25% of European haplotypes), and a virtually absent African genetic component (0.00 ± 10.31% by ML; 9.26% of African haplotypes).

Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic., The research was funded by the Max Planck Society, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (771234–PALEoRIDER, to W.H.; 805268–CoDisEASe to K. Bos; 834616–ARCHCAUCASUS to S.H.), the Slovak Academy of Sciences and the European Union’s Seventh Framework Programme and Marie Curie Actions under the Programme SASPRO (1340/03/03 to P.C.R.), the ERA.NET RUS Plus–S&T programm of the European Union’s Seventh Framework Programme (277–BIOARCCAUCASUS to S.Re. and S.H.), the Werner Siemens Stiftung (“Paleobiochemistry”, to CW), the Award Praemium Academiae of the Czech Academy of Sciences (to M.E.), the Institute of Archaeology of the Czech Academy of Sciences (RVO 67985912, to M.Dobe.), the Russian Foundation for Basic Research (19-09-00354a, to M.K.K. and V.V.K.; 19-78-10053 to SSh), the German Research Foundation (DFG-HA-5407/4-1–INTERACT to W.H. and RE2688/2 to S.Re.), the French National Research Agency (ANR-17-FRAL-0010–INTERACT, to M.F.D., M.Ri., S.Ro., S.Sai., D.Bi., and P.Le.), the Wenner-Gren Dissertation Fieldwork Grant (9558 to S.Sab.), and the Ministry of Education and Science of the Republic of Kazakhstan (AP08856654 to L.B.D., L.M., and E.Kh. and AP08857177 to A.Z.B.).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 112 Mexicans from the state of Morelos living in the city of Cuernavaca (N = 82) and rural communities (N = 30), to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes in Morelos include seven Native American, one European, one African and one Asian haplotype. Admixture estimates revealed that the main genetic components in Morelos are Native American (60.43 ± 2.22% by ML; 53.57% of Native American haplotypes) and European (39.58 ± 3.70% by ML; 27.68% of European haplotypes), and a virtually absent African genetic component (0.00 ± 4.93% by ML; but 11.16% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 479 Mexicans from the state of Durango living in Durango city (N = 153) and rural communities (N = 326), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Durango include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in Durango are European (54.34 ± 1.68%) and Native American (45.66 ± 2.24%), while African genetic component was virtually absent (0.00 ± 2.03%). However, African haplotypes could be estimated at a proportion of 9.13%.

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 (N = 45) and rural communities (N = 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 ± 4.42% by ML; 42.61% of Native American haplotypes) and European (48.18 ± 3.55% by ML; 46.02% of European haplotypes), with a virtually absent African genetic component (0.00 ± 4.25% by ML; 4.55% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 117 Mexicans from the state of San Luis Potosí living in the city of San Luis Potosí (N = 30) and rural communities (N = 87), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state include 13 Native American, six European, two African and two Asian haplotypes. Admixture estimates revealed that the main genetic components are Native American (52.72 ± 0.66% by ML; 48.29% of Native American haplotypes) and European (34.62 ± 4.28% by ML; 32.48% of European haplotypes), and a relatively high African genetic component (12.66 ± 4.61% by ML; 10.26% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 684 Mexicans from the state of Coahuila living in Saltillo (N = 72), Torreón (N = 396) and rural communities (N = 216), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Coahuila include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Coahuila are European (49.72 ± 4.18% by ML; 37.49% of European haplotypes) and Native American (45.01 ± 2.69% by ML; 42.98% of Native American haplotypes), while African genetic component is less apparent (5.27 ± 1.88% by ML; 9.92% of African haplotypes).

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 (N = 52) and rural communities (N = 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 ± 0.58% by ML; 53.16% of Native American haplotypes) and European (26.39 ± 5.05% by ML; 25.86% of European haplotypes), and a less prominent African genetic component (2.00 ± 5.20% by ML; 9.77% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 286 Mexicans from the state of Sinaloa living in Culiacán (N = 103) and rural communities (N = 183) to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes for the state of Sinaloa include ten Native American most probable ancestry and five European most probable ancestry haplotypes. The admixture estimates revealed that the main genetic components in the state of Sinaloa are European (62.39 ± 3.47%) and Native American (37.61 ± 2.85%), while the African genetic component was estimated as virtually absent (0.00 ± 1.86%).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1113 Mexicans from the state of Veracruz living in the cities of Coatzacoalcos (N = 55), Orizaba (N = 60), Córdoba (N = 56), Poza Rica (N = 45), Veracruz (N = 171), Xalapa (N = 187) and rural communities (N = 539) to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes include 12 Native American haplotypes. Admixture estimates revealed that the main genetic components are Native American (64.93 ± 1.27% by ML; 55.10% of Native American haplotypes) and European (26.56 ± 0.89% by ML; 28.38% of European haplotypes), and a relatively high African genetic component (8.52 ± 1.82% by ML; 8.78% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 148 Mexicans from the state of Tamaulipas living in Ciudad Victoria (N = 23) and rural communities (N = 125), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in the state of Tamaulipas include ten Native American, three European and one African haplotypes. Admixture estimates revealed that the main genetic components in the state of Tamaulipas are Native American (54.69 ± 0.93% by ML; 47.65% of Native American haplotypes) and European (34.66 ± 5.62% by ML; 33.56% of European haplotypes), and a relatively high African genetic component (10.65 ± 5.05% by ML; 12.42% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 439 Mexicans from the state of Sonora living in Ciudad Obregón (N = 143), Hermosillo (N = 99), and rural communities (N = 197) to obtain information regarding allelic and haplotypic frequencies. We find that the 13 most frequent haplotypes for the state of Sonora include nine Native American, three European and one Asian haplotypes. Admixture estimates revealed that the main genetic components in the state of Sonora are European (51.25 ± 2.90% by ML; 37.70% of European haplotypes) and Native American (43.35 ± 2.57% by ML; 39.64% of Native American haplotypes), while the African genetic component was less apparent (5.39 ± 2.54% by ML; 11.04% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 636 Mexicans from the state of Oaxaca living in the city of Oaxaca (N = 151) and rural communities (N = 485), to obtain information regarding allelic and haplotypic frequencies. We found that the 13 most frequent haplotypes in Oaxaca are all of putative Native American origin. Admixture estimates revealed that the main genetic components in the state of Oaxaca are Native American (73.12 ± 2.77% by ML; 61.52% of Native American haplotypes) and European (17.36 ± 2.07% by ML; 20.69% of European haplotypes), and a relatively high African genetic component (9.52 ± 0.88% by ML; 8.94% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 104 Mexicans from the state of Colima living in the city of Colima (N = 61) and rural communities (N = 43), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Colima include eight Native American, two European and one African haplotype. Admixture estimates revealed that the main genetic components in the state are Native American (52.74 ± 3.88% by ML; 48.10% of Native American haplotypes) and European (37.52 ± 8.94% by ML; 26.66% of European haplotypes), and a relatively high African genetic component (9.74 ± 8.40% by ML; 11.91% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 98 Mexicans from the state of Quintana Roo living in the city of Cancún (N = 48) and rural communities (N = 50), to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We found that the most frequent haplotypes in Quintana Roo include ten Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in Quintana Roo are Native American (80.85 ± 3.70% by ML; 60.20% of Native American haplotypes) and European (15.19 ± 14.25% by ML; 26.02% of European haplotypes), and a less prominent African genetic component (3.96 ± 10.75% by ML; 6.63% of African haplotypes).

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 (N = 41) and rural communities (N = 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 ± 2.16% by ML; 54.51% of Native American haplotypes) and European (32.49 ± 2.88% by ML; 28.69% of European haplotypes), and a relatively high African genetic component (8.58 ± 0.93% by ML; 6.97% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 224 Mexicans from the state of Tabasco living in the city of Villahermosa (N = 82) and rural communities (N = 142), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in Tabasco include 13 Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in Tabasco are Native American (67.79 ± 1.59% by ML; 56.25% of Native American haplotypes) and European (27.21 ± 3.97% by ML; 29.91% of European haplotypes), and a less prominent African genetic component (5.01 ± 4.42% by ML; 8.93% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 324 Mexicans from the state of Yucatán living in the city of Mérida (N = 192) and rural communities (N = 132), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in the state of Yucatán include 16 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Yucatán are Native American (81.54 ± 4.99% by ML; 62.92% of Native American haplotypes) and European (11.50 ± 15.43% by ML; 23.26% of European haplotypes), and a less prominent African genetic component (6.96 ± 10.47% by ML; 5.93% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 665 Mexicans from the state of Nuevo León living in the city of Monterrey (N = 226) and rural communities (N = 439), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Nuevo León include 12 Native American and three European haplotypes. Admixture estimates revealed that the main genetic components in the state of Nuevo León are Native American (54.53 ± 0.87% by ML; 48.88% of Native American haplotypes) and European (38.67 ± 4.06% by ML; 32.59% of European haplotypes), and a less prominent African genetic component (6.80 ± 4.30% by ML; 8.26% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 262 Mexicans from the state of Guanajuato living in the cities of Guanajuato (N = 78), León (N = 22) and rural communities (N = 162), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes found in the state of Guanajuato include 12 Native American and three European haplotypes. Admixture estimates revealed that the main genetic components in the state of Guanajuato are Native American (50.64 ± 2.11% by ML, 43.35% of Native American haplotypes) and European (44.14 ± 1.14% by ML; 39.35% of European haplotypes), while African genetic component is less apparent (5.22 ± 2.08% by ML; 8.36% of African haplotypes).

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 161 Mexicans from the state of Nayarit living in Tepic (N = 97) and rural communities (N = 64), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Nayarit include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Nayarit are Native American (50.79 ± 5.03% by ML; 42.24% of Native American haplotypes) and European (37.04 ± 6.21% by ML; 35.72% of European haplotypes), while African genetic component is less apparent but relatively high (12.17 ± 2.50% by ML; 13.36% of African haplotypes).

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 ± 2.69% by ML; 54.17% of Native American haplotypes) and European (35.01 ± 4.59% by ML; 32.29% of European haplotypes), and a relatively low African genetic component (3.63 ± 2.38% by ML; 5.90% of African haplotypes).

The forced relocation of several thousand Africans during Mexico?s historic period has so far been documented mostly through archival sources, which provide only sparse detail on their origins and lived experience. Here, we employ a bioarchaeological approach to explore the life history of three 16th century Africans from a mass burial at the San José de los Naturales Royal Hospital in Mexico City. Our approach draws together ancient genomic data, osteological analysis, strontium isotope data from tooth enamel, δ13C and δ15N isotope data from dentine, and ethnohistorical information to reveal unprecedented detail on their origins and health. Analyses of skeletal features, radiogenic isotopes, and genetic data from uniparental, genome-wide, and human leukocyte antigen (HLA) markers are consistent with a Sub-Saharan African origin for all three individuals. Complete genomes of Treponema pallidum sub. pertenue (causative agent of yaws) and hepatitis B virus (HBV) recovered from these individuals provide insight into their health as related to infectious disease. Phylogenetic analysis of both pathogens reveals their close relationship to strains circulating in current West African populations, lending support to their origins in this region. The further relationship between the treponemal genome retrieved and a treponemal genome previously typed in an individual from Colonial Mexico highlights the role of the transatlantic slave trade in the introduction and dissemination of pathogens into the New World. Putting together all lines of evidence, we were able to create a biological portrait of three individuals whose life stories have long been silenced by disreputable historical events.

Umbilical cord blood stem cell transplantation is an important choice for treating a variety of hematopoietic, neoplastic, and genetic disorders. The optimal size for a cord blood bank to provide matching units for 80% of patients requiring a stem cell transplantation procedure depends on the particular characteristics of each population. In this study, we analyzed the immunogenetic diversity of a sample set of Mexican patients suffering from blood, hematopoietic, and immunological diseases, to assess the best strategy for cord blood banking. For achieving that, we analyzed HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1 genotype and allele frequencies of both units from the bioarchive of the Umbilical Cord Blood Bank from La Raza and patients requiring a stem cell transplant and compared these variables with data from the same geographic and genetic context. We were able to detect significant differences for at least half of the alleles were observed for HLA class I and class II genes between units and patients. Five Native American haplotypes had lower frequencies in patients sample than in the cord blood units. Genetic admixture estimations for both groups showed a higher contribution of Native American component in the cord blood units. Differences in ancestral components in the Umbilical Cord Blood Bank from La Raza and six virtual banks modeled from a pool of Mexican mixed ancestry individuals show that genetic background is important in cord blood collection. In conclusion, increasing diversity over quantity of new cord blood units will improve the cost effectiveness of cord blood banking and health policies regarding hematopoietic stem cell transplantation in admixed populations such as those present in Latin American countries.

Idiopathic achalasia is a relatively infrequent esophageal motor disorder for which major histocompatibility complex (MHC) genes are well-identified risk factors. However, no information about HLA-achalasia susceptibility in Mexicans has previously been reported. We studied a group of 91 patients diagnosed with achalasia and 234 healthy controls with Mexican admixed ancestry. HLA alleles and conserved extended haplotypes were analyzed using high-resolution HLA typing based on Sanger and next-generation sequencing technologies. Admixture estimates were determined using HLA-B and short tandem repeats. Results were analyzed by non-parametric statistical analysis and Bonferroni correction. P-values < 0.05 were considered significant. Patients with achalasia had 56.7% Native American genes, 24.7% European genes, 16.5% African genes and 2.0% Asian genes, which was comparable with the estimates in the controls. Significant increases in the frequencies of alleles DRB1*14:54 and DQB1*05:03 and the extended haplotypes DRB1*14:54-DQB1*05:03 and DRB1*11:01-DQB1*03:01, even after Bonferroni correction (pC