Analysis of the European polymorphisms in lactase gene between ethnic groups in the Colombian Caribbean

The prevalence of adult-type hypolactasia is influenced by ethnicity and geography. The CC and GG genotypes of the SNPs C/T-13910 and G/A(-22018') respectively indicate hypolactasia in certain ethnic groups worldwide. The aim of this study was to analyse these SNPs in samples of the three ethnic groups that inhabit the Colombian Caribbean. Three hundred and sixty-one subjects were genotyped using PCR/RFLP. These subjects were grouped as being of African descent, Indigenous and Mestizo. The genetic analysis was performed through Arlequin 3.11 and genotype frequencies were compared with Statgraphics Centurion XVI. Only SNP C/T-13910 showed Hardy-Weinberg equilibrium and there was no linkage disequilibrium between the SNPs. The frequency of CC-13910 was 90% in Afro-descendant, 95% in indigenous people and 80% in mestizos. The frequency of GG(-22018) was 23% in indigenous people, but this genotype was not present in afro-descendants and Mestizos. The indigenous people did not have AA(-22018') and none of the groups had TT-13910 degrees. The genotype frequencies were statistically different among the groups studied and the frequencies of CC-13910 and GG(-22018) were not in concordance with the phenotype frequencies reported in other papers. The results suggest that diagnostic possibility of hypolactasia by genotyping of those polymorphisms in the Colombian Caribbean population is scarce.