HLA class I and class II polymorphism in a population from south-eastern Tunisia (Gabes Area)

The gene frequencies of HLA class I and class II alleles were investigated in 95 healthy Tunisian individuals from Gabes. Our aim was to compare the genetic relationship between Gabesians and Mediterraneans and sub-Sahara Africans using genetic distances, Neighbour-Joining dendrograms, correspondence and haplotypes analysis, thereby providing additional information about evolutionary history of modern-day Tunisians. Subjects were unrelated and of both genders, and HLA class I and class II genes were genotyped using the polymerase chain reaction-sequence specific primer (PCR-SSO) technique. Our data show that south-eastern Tunisians (Gabes area) are related to present-day North Africans (Algerians, Moroccans, Tunisians) and Iberians (Spaniards, Basques), and along with other North Africans, appear to be genetically related to Berbers, an indication that the Arab invasion (7th-11th centuries) of North Africa had minimal contribution on the HLA makeup of North Africans. On the other hand, Iberians including Spaniards and Basques show relatedness to (native Tunisian) Berbers, suggesting that the gene flow of 7th century AD invaders was also low in Iberians. In conclusion, the successive invasions of North Africa in general, and Tunisia in particular, did not modify markedly the genetic makeup of present-day Tunisians. With the exception of Greeks who have a sub-Saharan genetic profile, all Mediterranean populations depict a typical mediterranean substratum.