I believe one copy of only one of the defective genes is inconclusive, because we just don’t have a way to know if that gene is switched on or off/ expressed in an individual or not. That is why having a compound result (two of one bad gene or one each of two bad genes) is considered having a stronger association with being unable to metabolize B6, B12 and Folic Acid. My naturopath would do the same as yours, MattiesMom, try the activated folate and if you feel better you know you need it without doing the test. Also, none of my children are autistic.
I have had the genetic testing and came back as “compound heterozygous” with one copy each of C677T and A1298C. Per the lab report “This genotype is predicted to be associated with a poor metabolizer phenotype characterized by increased plasma homocysteine levels. This individual is at increased risk for arteriosclerotic coronary disease and venous thrombosis as well as for toxicity from medications affecting folate metabolism.”
A person with the MTHFR gene defect need to take activated forms of the above vitamins. I was taking the Thorne 5MTHF and Thorne Methylguard (for the B6 & 12), but I need such a high level of folic acid that the cost was getting too much to buy the Thorne 5MTHF. Also, my husband has the gene defect, and the cost goes through the roof when you are both taking 30 mg of activated folate a day. So, we are now getting it RX for it (brand name is Deplin, but there is also a generic L-Methylfolate Calcium that is MUCH cheaper!) and saving a lot of money! 90 day mail order through our insurance, for 30 mg a day, is $30. So much less than the Thorne! We still are taking Thorne Methylguard, but my naturopath is getting us set up to do activated B12 injections at home soon.
Haven’t had our kids tested yet, and we need to, especially the girls, at least before they get married and have babies, as low folate is linked to neural tube defects, pregnancy complications/miscarriages and delivery complications (all of which I have had, except the neural tube, though on most of my 8 miscarriages we don’t know if something was wrong with the baby or not).
Hope that helps to hear from someone who has had the testing done.