Las Alpujarras region (South East Spain) HLA genes study: evidence of a probable success of 17th century repopulation from North Spain

Conquest of Granada Muslim Kingdom (1492 AD) finished with Muslim occupation; they were mostly North African Berbers who had reached Iberia by 711 AD. A politics of Iberian Christianization followed after this date: Jewish were expelled in 1492 and Moriscos (Spaniards practicing Muslim religion or speaking Arab) were expelled from all Spanish territory on 1609 AD. Las Alpujarras is a southern Spain mountainous secluded region, which underwent a repopulation from North Spain and a specific Muslim (Moriscos)–Christian war took place according to historical records. Both Las Alpujarras repopulation by northern Iberians and Moriscos expulsion success have been debated and are regarded as non-clarified episodes. In this study, we have addressed the question whether the repopulation succeeded by determining HLA genes of present day Las Alpujarras inhabitants and compared with those of other Mediterranean populations HLA frequencies and genealogies. HLA frequencies show ambiguous results because of extant HLA similar gene frequencies there exist in North Africa and Spain. This is reflected by the finding of North and South western Mediterraneans close relatedness of HLA dendrograms and correspondence analyses. However, the genealogical study of extended HLA haplotypes particularly Alpujarran high frequency of HLA-A29-B44-DRB1*0701-DQA1*02-DQB1*02 (not found in Algerians but frequent in North and Central Spain) and Alpujarran low frequency extended haplotype HLA-A3-B7-DRB1*1501-DQA1*0102-DQB1*0602 (frequent in North Europe) reveals that a significant HLA gene flow from North Spain is observed in present day Alpujarrans: both haplotypes are characteristic of North Spain and North Europe, respectively. This may indicate that enforced Alpujarran repopulation from North Spain may have been a success, which was started by Spanish King Philip II in 1571 AD.