Research indicates that genetic variations are key for understanding the genetic basis of complex traits and diseases. Variants can influence phenotypes, the susceptibility of an individual to disease, drug response and human genome evolution. Many SNPs have been associated with common disorders such as diabetes, obesity, and cardiovascular diseases. Further research into identifying the risk factors and understanding the biology of risk variants would enable a more complete view of these conditions and lead to improved disease treatment and prevention.
The MTHFR C677T mutation at nucleotide 677, which substitutes valine for an alanine at amino acid 222, is associated with reduced enzyme activity and elevated total homocysteine levels in serum or plasma. The MTHFR A1298C mutation, which substitutes a glutamate for an alanine at amino acid 429, is also associated with increased homocysteine and lowered plasma folate levels when present in combination with the C677T mutation.