Just because you have an MTHFR C677T/A1298C mutation doesn’t mean you’re over or under methylated (although it would be one factor that might push the balance to undermethylation). Dr. Walsh (Walsh Research Institute) describes one’s methylation status as being like a tug of war between opposing factors. Many of those are genetic, and some are nutritional or environmental.
According to Dr. Walsh’s research, 70% of the population are normal methylators, 22% are under-methylators, and 8% are over-methylators, but this again may depend on what you define as under/over-methylation/normal. Pfeiffer statistic says 45% are under-methylators and 15% are over-methylators (only 40% normal). This is just a matter of definition of the "normal" area. Undermethylation indicates that the methylation cycle as a whole slows down enough that the end product, SAMe, is typically inadequate and thus causes symptoms.
One and each of these symptoms is not a reliable indicator by it self since it could be caused by other factors. However, if you recognize most or many of these symptoms, being undermethylated might be the underlying problem. You might not have most of the symptoms of course, even if you are severely undermethylated. Look at symptoms first, then one can try supplementing with SAMe* for a while, and if that makes you feel better (and not worse) you should add the cofactors if you have not done so already. Blood test measuring SAM/SAH ratio is the most reliable lab-test. Genetic testing could give some hints, but does not provide any definite answers so far. 677T & 1298C mutations (methylenetetrahydrofolate reductase) could be a small clue, but one could be undermethylated without any mutation in these genes and vice versa. The presence of one or more of these mutations isn’t enough to say if you’re an over or under methylator. The combination of all of your genetic factors as well as your nutritional state must be taken into account. The best way to determine is through symptoms and traits.
*Be aware if you have high homocysteine levels before you try SAMe. Most undermethylated people have low homocysteine (contrary to what many people think), so that should not be a problem, to begin with for most people. High levels of homocysteine results in narrowing of blood vessels, and small concentrations the opposite.
Methyl (CH3) is the simplest organic molecule and is responsible for a vast number of functions in our body. Methyl is for instance used in DNA-methylation (protein production necessary for gene expression) and is also the essential component for formation of neurotransmitters controlling brain function. Therefore there will be some significant symptoms, both physical and psychological):
1. (Psychological) Depression, maybe mild. You might not be aware of it yourself since it has been like that all your life, even though other people enjoy life, social activities, music and laugh more than you. Getting up in the morning might not be one of your favorite things to do. Little energy. The reason is low levels of neurotransmitters.
2. (Both physical due to capillaries, and also because of being low on neurotransmitters): Low pain threshold (easily burned, etc.)
3. (Other psychological symptoms) Poor short-time memory* and not remembering dreams (due to lacking vitamin B6 and key neurotransmitters). High accomplishment and self-motivated (read: loner), very strong willed but poor concentration endurance, bouts of adrenal exhaustion. Shy, antisocial personality, infrequent and terse speech, obsessive-compulsive tendencies (OCD), intrusive/excessive thoughts interfering with daily life, oversensitive, phobias, inner tension, strong will, competitiveness (especially in sports and games), perfectionist, not satisfied with body, might wake up at night (easily woken), unwillingness/noncompliance to be treated/therapies (do it yourself), denial of illness (hiding problems), lack of empathy (psychopathic tendencies in severe cases), not showing emotions, catatonic, calm but inner tension, episodes of blank mind, oppositional as child/youth, cries easily, phobias, ritualistic behaviour, internal anxiety, rumination about past events, delusions, dietary inflexibility, high libido, easy orgasm, not hitting notes, not so interested in music. Same reason as above (low on neurotransmitters). High histamine and low serotonin, dopamine, and norepinephrine.
4. (Physical) High body temperature, profuse perspiration, heavy salivary flow/tears etc., strong teeth, prominent incisors, veins often prominent, more capillaries give you, for instance, quicker sunburn (depends on skin complexion), and frostbites. Sparse facial/body hair (beard/chest/arm/leg) with men (weaker hair growth). Acne*, early aging* (wrinkles, etc.), gray hair* and white spots* on fingernails (due to lacking Zinc/SAM-e). Maybe larger ears (growing due to excessive heat), long fingers and toes (depending on other genetics also). Prone to sneezing in sunlight, seasonal allergies (if high histamine), autoimmune diseases, cancer, respiratory allergies/asthma, rhinitis, hives, glue ear, osteoporosis, arthritis, cataracts, MS, lupus, headaches, backaches, muscle cramps (due to lacking magnesium), peptic ulcers, autoimmune disorders, anorexia and bulimia. Women give birth to mostly male offspring. Fast metabolism: might have a lean build despite hearty appetite (depending on other factors of course).
This list is not complete.
Due to mostly male offspring from women, most likely either your father only (mostly) had brothers or you mothers father only (mostly) had brothers. Then again the parent/grandparent who only had brothers had a mother that was undermethylated and then again had a father with only (mostly) brothers and so on (this is not 100% certain of course, but very likely). The undermethylated mother usually gives birth to male children because thin copious vaginal secretions foster the creation of males.
There are both benefits and disadvantages from being undermethylated, but correcting imbalances (especially undermethylation) will probably only be experienced as beneficial in many ways (chances of being over-methylated are small, and moving towards the "normal" area is only beneficial both mentally and physically).
Undermethylation is often combined with *Pyroluria caused by stress that depletes the body even more of vitamin B6, magnesium, and zinc (which is already quite low with under-methylators). If so, these symptoms can occur also: dry/pale skin, stretch marks, acne, acetonic breath/body odor, delayed growth puberty, inability to tan, sunburned, white spots on fingernails, early gray hair, frequent infections, morning nausea, hypersensitive to light and noise, poor sense of smell/taste, preference for spicy food, sensitive to gluten/casein, oxidative stress, stitch in side when running, extreme mood swings, poor stress control, overwhelmed of criticism, adverse to changes in routine, histrionic behaviour, impulsive, fatigue, less dream recall, problem with sugar metabolism, intolerance/sensitivity to some proteins/alcohol and others.
The over-methylator might have the opposite symptoms than many of these (high pain threshold, cold, heavy body hair, eczema, dry eyes and mouth, higher musical interest and extrovert, etc.). If that is the case, VITACURE® METHYL PLUS™ and SAMe is not for you. Undermethylation is much more widespread than over-methylation (about three times more common). Both biotypes struggle with addiction. The difference is the cause: over-methylators turn to drugs to try and suppress high anxiety or panic as a result of too much neurotransmitter activity, while under-methylators become obsessive compulsive with a substance or concept because of little neurotransmitter activity. The preferred drug might be different due to how they affect neurotransmitter activity.