A1298C hasn't really been found to be very interesting. It doesn't seem to have much effect on enzymatic activity, and the general consensus is that, especially in simple heterozygotes (those who lack a polymorphism on the other copy of MTHFR, such as C677T), A1298C can be ignored.
If you really want to be thorough, check your homocysteine levels - it's a cheap and fast blood test any doc can order for you. They will see it as a measure of cardiovascular risk. You can also get a lot more info by getting a 23andme, ancestry, or other similar SNP test and running the results through something like genetic genie (for methylation) or even promethease (which is more like drinking from a fire hose - if you lack a medical background, it will be very hard to interpret it all, and you might get unnecessarily freaked out - that's unlikely with genetic genie, which still gives you good methylation info).
My dad is a compound heterozygote in MTHFR (one allele from one parent is A1298C, and the other is C677T). Phenotypically, he is in excellent health in his late 60's, still working full time, and without any history of major chronic illness (no heart disease, no cancer, no diabetes, normal bp, normal blood lipids, no autoimmune disease, no inflammatory markers, normal major organ function, etc.)
I think more genetic testing is generally a good thing for any patient with ME, but based on the A1298C heterozygosity alone, I wouldn't be worried enough to do anything at all.