HLA alleles in the population of Cartagena (Colombia).

It is known from historical records that the population of Cartagena (Colombia) is a mixture of caucasoids (Spaniards) and negroids (Africans) that is named mulattos. The present study was carried out to determine the distribution of HLA antigens in this population. A sample of 370 individuals was HLA serologically typed; 91 of them were typed for Complement alleles and 47 were DNA typed using PCR amplification and oligonucleotide probes for the HLA-DQA1 locus. The analysis of the allele and haplotype frequencies obtained, together with the genetic distances calculated with other populations, showed that most of the HLA genes of mulattos are from negroids and caucasoids. The Asian and Amerindian contribution is small, consistent with the historical and socioanthropological documentation. For example, A23, Aw34, Aw36 and Bw45, as well as DQA1*0101, DQA1*0301 and BfF have frequencies similar to that observed in negroids. In contrast, many significant differences were observed when comparing the antigen and allele frequencies of mulattos with that of Asians and Amerindians. Our results add evidence to the notion that the arrival of Spaniards in America 500 years ago established several racial mixtures. The HLA characterization of one of these, mulattos, will allow a better application of the HLA technology in the fields of basic research, organ transplantation and forensic medicine among this population.