Colonia Tovar: the history of a semi-isolated Venezuelan population of German ancestry described by HLA class I genes.

Abstract

The history of Colonia Tovar is very complex, being the home of descendants of only a small fraction of immigrants arriving to the South American continent from a specific region of Germany, with a restricted number of founders, small population size and consanguineous mating, experiencing isolation for 100 years, with later migrations, a low rate of population growth and a high mean number of children per couple. How complex is its genetic structure? Do the highly polymorphic HLA genes reflect its history and confirm the story of this population described by other genes? Several studies have been made in this population, but we describe for the first time the HLA Class I variability in the population of Colonia Tovar using PCR-SSOP. Random genetic drift, founder effect and gene flow could explain the HLA allele and haplotype frequencies observed in this population but alleles at the class I loci were insufficient to identify the German origin of the community established through history. This agrees with findings obtained testing other genetic systems (ACP, AK, ESD, G6PD, GLO, PGM, PGD, ALB, CP, HP, TF), but the HLA-typing results indicate that the original gene pool has been diluted due to gene flow from the surrounding Mestizo population.