Gene and genotype frequencies for HLA-DQA1 in Caucasians and Mulattoes in Brazil

Gene and genotype frequencies of the HLA-DQA1 locus were determined in a sa mple of 197 unrelated individuals (144 Caucasians and 53 Mulattoes), living in the city of Sao Paulo, Brazil. The Mulatto group consisted of mixed ind ividuals who presented at least one negroid physical characteristic or decl ared themselves to be: of mixed ancestry. A total of six different alleles were identified with frequencies ranging from 0.087 to 0.316 in the Caucasi an population and from 0.066 to 0.330 in the Mulatto population, We observe d an increased frequency of allele 1.2 among Mulattoes in relation to Cauca sians. The sample heterozygote frequency was 0.722 among Caucasians and 0.7 36 among Mullatoes. No significant deviations from Hardy-Weinberg equilibri um were found either in the Caucasian or in the Brazilian Mullato populatio n samples.