HLA-DQa allelic frequencies detected with PCR in a variety of human populations.

Abstract

Polymerase chain reaction (PCR) amplification and oligonucleotide probe hybridization may be used to detect DNA polymorphisms rapidly in large samples. In this study, 475 individuals from thirteen human populations were allelotyped at the human leukocyte antigen (HLA) DQa (DQA1) locus. A 242 or 239 bp fragment was amplified from each individual's DNA. Each of six alleles was detected by hybridization to allele specific oligonucleotide probes (ASOs). Allelic frequencies varied between populations, but the measure of gene frequency variation among populations, the FST value, was relatively low. Most populations had genotypic frequencies in agreement with Hardy-Weinberg equilibrium expectations. Principal component analysis was performed on the populations, and results are presented in graphic form. The heterozygosity at this locus is high in all populations; the average (74%) is close to the theoretical maximum (83%) for a 6 allele system. It is likely that this system is affected by stabilizing selection, which makes it less than optimal for the study of random evolutionary divergence between populations.