I know this post was from way back..but I have this mutation.
It *may* have contributed to my many miscarriages, although genetic deletions/syndromes are much more likely. We know it likely caused me to have a serious placental abruption and high blood pressure w/ds1's pregnancy (he was born at 29 weeks). In my second pregnancy, it may have contributed to my low amniotic fluid (may have had in first pregnancy, too, but was undx'd) and another early delivery.
They don't know much about this in kids. It is a common genetic mutation. It has been seen in at least one study that there is an increased risk of depression/anxiety/bipolar disorder w/the MTHFR mutation, and it has been seen in many to be associated w/high blood pressure and blood clots (ones that contribute to DVT's and clots in the placenta). There are several different types of this mutation, and some are more harmful than others.
Treatment is folate (sold OTC by Solgar as Metafolin or prescription in a few medical supplements like Metanx) and baby aspirin (only if a doctor who knows about MTHFR prescribes!), and in pregnancy, sometimes additional blood thinners. Many doc recommend fish oil be taken daily as well. I will be on folate and fish oil for the rest of my life, and take aspirin when pregnant. I'm watched carefully for blood clots--which I did have w/my recent pregnancy--and if needed, will take blood thinners during pregnancy.
Don't know anything about anesthesia being a special risk, as I've had 4 major surgeries, and this has NEVER come up.