Single Nucleotide Polymorphisms of MTHFR (rs1051266) and SLC19A1 (rs1801133) Associated to Genomic Ancestry in Cuban Healthy Population

Several single nucleotide polymorphisms on methotrexate pathway have been implicated with hyperhomocysteinemia, susceptibility to autoimmune diseases and the therapy effectiveness of methotrexate. The present study estimates the ethnogeographic prevalence of rs1801133 (c.665C>T) in methylenetetrahydrofolate reductase and rs1051266 (c.80A>G) in solute carrier family 19 member 1, according to genomic ancestry analysis in Cuba healthy population. Genomic data was collected from a dense genome-wide genotyping array analysis of a large sample of individuals from all provinces of Cuba, with a final sample of 946 individuals for rs1801133 and 948 individuals for rs1051266. For rs1801133, T allele and TT genotype were more prevalent in Mayabeque, the province with the highest European (p<0.0001) and the lowest African ancestry proportion (p<0.0001). Whereas, T allele and TT genotype frequency were low in Guantánamo (23.7% and 1.8%), the province with the highest African ancestry proportion (p<0.0001) and the lowest European ancestry proportion (p<0.0001). For rs1051266, the higher frequency of G allele was observed in Villa Clara, Las Tunas, Holguín and Granma and this group was associated with AG and GG genotypes (p=0.0045). This seems to be related to high Native American ancestry proportion in Las Tunas (p<0.0001), Holguín (p<0.0001) and Granma (p<0.0001); with the low African ancestry proportion in Villa Clara (p<0.0001) and with a Native American ancestry-enriched pattern observed for these provinces (p=0.0005). These results provide evidence that ancestry contribution impacts in the ethnogeographic prevalence of rs1801133 (c.665C>T) and rs1051266 (c.80A>G) polymorphisms in healthy Cuban individuals.