Sequence diversity of the Rh blood group system in Basques. Homo sapiens

Basques show specific cultural, demographic and genetic characteristics that have placed them as an isolated and unique population within Europe, such as their non-Indo-European language, Euskara. They have historically lived along the Western Pyrenees, between Spain and France, in one of the most important European glacial refugia during the Last Glacial Maximum. The most striking genetic characteristic is their highest frequency of the RhD blood group negative allele, a variant related to the hemolytic disease of the newborn. Both demographic and adaptive processes have been suggested as possible causes of the high frequency of RhD negative in Basques, but neither hypothesis has been clearly demonstrated. While previous studies on the Rh system in Basques have been mostly focused on serological and genotyping diversity, in this work we analyze genotyping and next generation sequencing data in order to provide a general framework of the genetic scenario of the system and better understand the polymorphism in Basques . In particular, we genotyped the most relevant variants of the system (D/d, E/e, and C/c), and sequenced three ~6Kb flanking regions surrounding the Rh genes in Basques and also in other populations for comparison.