Immune-genetic study of the new populations of Sierra Morena (Spain) through HLA polymorphisms of class I.
We have studied the HLA antigenes of class I in 50 families from Andalusia and in 50 families from some towns of Sierra Morena (La Carolina among others), in which an important settlement took place by individuals from Central Europe over 200 years ago, by comparing the allele frequencies with the German population. The obtained results allowed us to conclude that a real mixture of population has occurred. The frequencies of some HLA alleles of class I in the population of Sierra Morena are intermediate to those observed in the original populations, though some phenomena of drifting have been noticed. The study of gametic associations also shows that the population of Sierra Morena behaves as an intermediate population between the two original populations. This is evident in relation to the A1-B8 haplotype, in which the population of Sierra Morena is similar to the original Andalusian population, regarding the frequency of the haplotype, and the German population, because of the intensity of disequilibrium. The study of the genetic distances shows that the ones existing between the populations of Andalusia, Germany and Sierra Morena are small, although they reveal that these populations are clearly defined.