Does fadh2 play the same role in mthfr mutated forms as it does in the otherwise normal form, and could mthfr mutation alone cause fadh2 depletion?

Homocysteine: The majority of population has at least a single MTHFR mutation and around 40% have a double mutation (either heterozygous (one of each) A1298C & C677T, homozygous (two) C677T or homozygous A1298C). The MTHFR enzyme metabolizes folic acid into 5-MTHF, needed to combine with homocysteine. What is often seen with MTHFR mutations are: elevated homocysteine levels and defective methylation.