MTHFR and hyperhomocysteinemia: We have observed that individuals with either CT or TT variant of MTHFR 677 along with folate deficiency have nearly 5 times increased risk of hyperhomocysteinemia, while risk of hyperhomocysteinemia increases 4.33 fold in individuals carrying CT or TT variant of MTHFR 677 with vitamin B 12 deficiency.