Not a horrible thing, but if heterozygous can cause a problem with homocysteine levels b
/c your body cannot absorb Vitamin B
and Folic Acid. As they cannot really find an underlying cause for you, I would suggest researching this or asking them to do a simple blood test. Most people never know thay have it as about 50% of caucasians in the US have some variant of the mutation, few feel any symptoms of it, but this could be an underlying cause for you.