MTHFR and autoimmune polyendocrinopathy: Another study also found that the MTHFR C677T polymorphism was equally distributed among the four groups, including the thrombotic group without APS, healthy controls, APS, and aPL(+) patient groups; however, the APS patients who had a homozygous genotype for the MTHFR C677T polymorphism had a lower age at their first thrombosis event, they had more thrombotic events, and higher homocysteine levels, compared with those APS patients who had a non-homozygous genotype for polymorphisms [15].