HLA class I and II polymorphisms in Azores show different settlements in Oriental and Central islands

Abstract

Human leucocyte antigen-A, -B, -Cw, -DRB1, -DQA1 and -DQB1 polymorphisms were examined in the Azorean population. The data were obtained at high-resolution level, using polymerase chain reaction (PCR) with sequence-specific primer, PCR-sequence-specific oligonucleotides and sequence-based typing. The most frequent allele in each locus was: A*0201 (24.5%), B*510101 (9.8%), Cw*0401 (14.8%), DRB1*070101 (18.3%), DQA1*0201 (17.4%) and DQB1*0301 (19.4%). The predominant extended haplotype was A*0202-B*1503-Cw*0202-DRB1*090102-DQA1*0303- DQB1*0202 (1.9%), which was found to be absent in the Portuguese mainland. The present study corroborates historical sources that say the Azores were populated not only by Portuguese but also by other Europeans, mostly Flemish people. Despite dendrogram analysis showing some remote Asian genetic affinities, the lack of specific alleles and haplotypes from those populations does not allow us to conclude for direct influence. Haplotype and allele frequencies in Azores show no homogeneous distribution between Oriental and Central islands of this archipelago. The Oriental islands harbour several haplotypes already found in mainland Portugal and identified as Mediterranean and European. The Central group of islands on the contrary clearly shows an influence of north Europeans (most probably derived from a well-documented Flemish settlement), with much less affinity to mainland Portugal.

Self-Assessment of Color Categories and Its Relationship with HLA Profiling in Brazilian Bone Marrow Donors

“…This haplotype is found at low frequency only in European and North American populations [14] but has a 1.3% frequency in the Azores [22]. The state of Rio Grande do Sul experienced a strong Azorean immigration during the 18th century.…”

HLA Class I and II profiles in São Miguel Island (Azores): genetic diversity and linkage disequilibrium

“…This may be a direct consequence of the Azorean settlement, with a major contribution of mainland Portuguese (~60%) and, to a lesser extent, Flemish, Spanish, French, Italians, Germans, Scottish, Jews, Moors and blacks from Guinea, Cabo Verde and São Tomé. Previous studies of HLA markers in mainland Portugal (3 loci , -A, -B and -DRB1, [18]) and in Azores (6 loci , -A, -Cw, -B, -DRB1, -DQA1 and -DQB1, [5]) demonstrate values of average diversity of 0.92 in both populations. The results obtained in the present study, based in 7 loci , showed a smaller value (0.84).…”

HLA Class I and Class II Conserved Extended Haplotypes and Their Fragments or Blocks in Mexicans: Implications for the Study of Genetic Diversity in Admixed Populations

“…Principal Components Analysis (PCA) for 38 populations with HLA-B data available was performed using the IBM SPSS Statistics 19 software ( IBM Corporation, Armonk, NY, USA ) to analyse the distribution of HLA-B alleles in human groups of the proposed ancestries, Figure 1 . PCA included population data of Ireland [20], NW of England [61], Germany [62], Austria [63]; Spain, Italy, United Kingdom [64], France [65], Gypsy from Andalucía (Spain; data collected by López-Nevot et al ) [14], Azores Terceira Island [66], Forro from São Tomé Island [67], Beti from Cameroon [68], Bandiagara from Mali, Lusaka from Zambia, Luo and Nandi from Kenia [69], Mandeka from Senegal [70], Guinea Bissau [71], Aleut from Bering Island (Russia) [72], center of Japan [73], a cord blood bank of Tzu Chi Foundation (Taiwan) [74], Han from southern China [60], north India [75], Kensiu from Malasya [76], Kinh from Vietnam [77], Tarahumara from northern Mexico [17], Native Americans from Gila River (USA) [78], Yu’pik from Alaska (USA) [79], Mixtec, Zapotec, and Mixe from Oaxaca (Mexico) [16], Seri from Sonora (Mexico) [80], Navajo from New Mexico (USA) [81], Uro from Titikaka Lake (Peru) [82], and Toba from Rosario (Argentina; data collected by Cintia Marcos et al ) [14]. Also, two admixed populations from Mexico were included: a “Mexican Mestizo” sample [83] and a sample from Guadalajara City, western Mexico [23].…”