Genetic analyses in five western Mediterranean populations: variation at five tetrameric short tandem repeat loci

A population study of the Balearic (Majorca, Minorca, Ibiza, Chueta) and Valencia populations was carried out using the short tandem repeat loci HUMTHO1, D4S243, HUMF13A1, D18S535, and D12S391. All the populations sampled were found to be in Hardy-Weinberg equilibrium for the five markers analyzed. Several statistical analyses showed a clear displacement of the Chueta and Ibiza populations from the other populations sampled. These results are in agreement with those obtained from the analysis of classical markers and mitochondrial DNA restriction fragment length polymorphisms, as well as with the history of these populations. A comparative study performed with other European populations using three of the five markers selected for this study (HUMTHO1, HUMF13A1, and D12S391) revealed a clear differentiation only of the Chueta population. We detected a tendency for a west-east clinal distribution in the frequency of the HUMTH01*6 allele in the European and Mediterranean area. This distribution could reflect some of the migratory events that have happened throughout that area's history. The forensic usefulness of these markers can be judged by their highly combined power of discrimination (0.999997).