Relatedness among Basques, Portuguese, Spaniards, and Algerians studied by HLA allelic frequencies and haplotypes

Abstract

HLA-A, -B, -DRB1, -DQA1, and DQB1 alleles were studied in Iberian and Algerian populations by serology and DNA sequence methodologies. The genetic and cultural relatedness among Basques, Spaniards, and paleo-North Africans (Berbers or Tamazights) was established. Portuguese people have also maintained a certain degree of cultural and ethnic-specific characteristics since ancient times. The results of the present HLA study in Portuguese populations show that they have features in common with Basques and Spaniards from Madrid: a high frequency of the HLA-haplotypes A29-B44-DR7 (ancient western Europeans), A2-B7-DR15 (ancient Europeans and paleo-North Africans), and A1-B8-DR3 (Europeans) are found as common characteristics. Portuguese and Basques do not show the Mediterranean A33-B14-DR1 haplotype, suggesting a lower admixture with Mediterraneans; Spaniards and Algerians do have this haplotype in a relatively high frequency, indicating a more extensive Mediterranean genetic influence. The paleo-North African haplotype A30-B18-DR3 present in Basques, Algerians, and Spaniards is not found in Portuguese either. The Portuguese have a characteristic unique among world populations: a high frequency of HLA-A25-B18-DR15 and A26-B38-DR13, which may reflect a still detectable founder effect coming from ancient Portuguese, i.e., oestrimnios and conios; Basques and Algerians also show specific haplotypes, A11-B27-DR1 and A2-B35-DR11, respectively, probably showing a relatively lower degree of admixture. A neighbor-joining dendrogram place Basques, Portuguese, Spaniards, and Algerians closer to each other and more separated from other populations. Genetic, cultural, geological, and linguistic evidence also supports the hypothesis that people coming from a fertile Saharan area emigrated towards the north (southern Europe, Mesopotamia, the Mediterranean Islands, and the North African coast) when the climate changed drastically to hotter and drier ca 10 000 years B.C.

Origin of Ancient Canary Islanders Guanches: presence of Atlantic/Iberian HLA and Y chromosome genes and Ancient Iberian language

“…Berber characteristics drives the conclusion that the main ancestors that they are main "Guanches" ancestors. However, autosomal HLA characters common to Iberian and Berbers are formed (Arnaiz-Villena et al, 1997) and conjoint autosomal, mtDNA and Y chromosome markers study revealed a gene flow across the Strait of Gibraltar; it was ongoing in high rates since pre-Neolithic times (Currat et al, 2010). This makes difficult a distinction between Iberian and North West Africans on the bases of both autosomal and sex chromosomes markers.…”

Genetic structure of north-west Africa revealed by STR analysis

“…Some authors 28,29 studied HLA variation, and suggested, based on similar frequencies for some haplotypes, that Basques and Berbers had a common origin. This conclusion was challenged by new data and a proper numerical analysis.…”

Consequences of Population Structure on Genes Under Balancing Selection

“…In addition to the large and growing literature relating patterns of MHC polymorphism to known or inferred historical migration patterns (Arnaiz-Villena et al 1997;Erlich et al 1997;Grahovac et al 1998;Hatta et al 1999), there has recently been interest in using genes under balancing selection to study population differentiation directly. These studies assume that genes under selection can possibly tell us something about differentiation due to selective differences among subpopulations, which may be of particular interest in some species that are targets of conservation efforts, such as salmon Kim et al 1999) or bighorn sheep (Boyce et al 1997).…”