Relatedness among Lusitanian people and Basques, Spaniards, and Algerians studied by HLA allelic frequencies and haplotypes.

(by Department of Immunology, Universidad Complutense, Madrid)

HLA-A, -B, -DRB1, -DQA1, and DQB1 alleles were studied in Lusitanian (in modern Portugal), Iberian (in modern Spain) and Berberian (in modern Algeria) populations by serology and DNA sequence methodoligies. The genetic and cultural relatedness among those peoples, and paleo-North Africans (Berbers or Tamazights) was established. Lusitanian people have also maintained a certain degree of cultural and ethnic-specific characteristics since ancient times. The results of the present study in Lusitanian populations show that they have features in common with Basques and Spaniards from Galicia and Castille: 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 (Indo-Europeans) are found as common characteristics. Lusitanian (or Portuguese) and Basques do not show the Mediterranean A33-B14-DR1 haplotype, suggesting a lower admixture with Mediterraneans; Spaniards and Algerians do not 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, Berbers, and Spaniards is not found in Lusitanian either. The Lusitanian people 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 Lusitanian, i.e., iberian, konis (cónios) and oestrimnios; Basques and Berbers (from Algeria) 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 Lusitanian, Basques, 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, when the climate changed drastically to hotter and drier ca 10 000 years B.C.