Genetically Prescribed Vitamins
Newly discovered genetic variations could predict who needs more folic acid
Source: “The prevalence of folate-remedial MTHFR enzyme variants in humans”
Nick Marini et al.
Proceedings of the National Academy of Sciences 105: 8055-8060
Results: Scientists at the University of California, Berkeley, identified several new variations in the gene for methylenetetrahydrofolate reductase (MTHFR), an enzyme that converts the B vitamin folate (called folic acid in supplements) from one form into another. They found that some variants of the enzyme need more folate to work effectively, a finding that could have implications for human nutrition.
Why it matters: Scientists hope that this type of research will eventually pave the way for individually tailored doses of vitamins. In particular, the work may help suggest who needs to take more folic acid to prevent ailments such as birth defects and possibly heart disease, which have been linked to malfunction of the MTHFR enzyme.
Methods: Researchers sequenced the MTHFR gene in 564 people of different ethnicities. Then they added the human gene sequences to yeast cells, which were engineered so that their growth rate depended on how well the enzyme was working. By feeding the yeast varying amounts of folate, the scientists could determine which of the genetic variants needed more of the vitamin to function properly.
Next steps: An ongoing human study performed in collaboration with the Children’s Hospital Oakland Research Institute and the Joint Genome Institute in Walnut Creek, CA, should provide more data on the enzyme’s role in birth defects. Scientists will sequence the gene in 250 normal children and 250 children with neural-tube defects to see whether the poorly functioning variants appear more often in the latter.