This particular mutation has been studied in the context of cardiovascular disease and is known to disrupt the function of 5,10-methylenetetrahydrofolate reductase so that rs1801133(T;C) heterozygotes have 35% less function and rs1801133(T;T) homozygotes have 70% less function of the enzyme than rs1801133(C;C) homozygotes, resulting in increased homocysteine levels in blood.17 The minor allele (A) of another variant in MTHFR, rs1801131, causes change of glutamate in position 429 to alanine. Here, MTHFR is linked to cardiovascular disorder.