MTHFR and hypertensive disorder: In China, there are 300 million people with hypertension and of those, about 17.9 to 25% had MTHFR 677 TT genotype, that is, there are about 53.7 to 75 million hypertensive people with MTHFR 677 TT genotype.9,10 A meta-analysis in the Lancet showed that the MTHFR 677 TT genotype compared with CC homozygotes increased the risk of stroke in Western populations without cardiovascular disease by 26%.11 Therefore, identifying an effective biomarker among MTHFR 677 TT genotype to guide folic acid treatment is important for reducing first stroke risk.