MTHFR gene test TT type means that the gene is a pure mutation type, at this time, only about 30% of MTHFR enzyme activity is left, and it is easy to have folic acid deficiency. 1.MTHFR is methylenetetrahydrofolate reductase, which has an important effect on human folate metabolism, and the results of MTHFR gene test mainly include CC type, CT type and TT type. Among them, CC type is wild type with normal folate metabolism level, while CT type is heterozygous mutant with 65% enzyme activity. 2. For TT type, it belongs to the high risk of folic acid deficiency. Since the enzyme activity is only 30%, the body’s ability to absorb and metabolize folic acid is poor, so in addition to the daily diet, additional use of folic acid supplements is also required. 3. Clinical trials have shown that folic acid deficiency may lead to fetal congenital malformations such as Down’s syndrome and neural tube malformations, and increase the risk of pregnancy complications such as gestational hypertension, in addition to its correlation with cardiovascular disease. Therefore, people with TT, especially those who are preparing for pregnancy or pregnant and breastfeeding women, need to pay great attention to timely medical treatment and take folic acid supplements under the guidance of a physician to accurately replenish the required amount of folic acid.