MTHFR gene variations can affect how the body processes folate and may lead to elevated homocysteine levels, which are sometimes linked to symptoms like fatigue, brain fog, mood changes, headaches, or cardiovascular concerns—though many people with these variants have no symptoms at all. Because these effects can be nonspecific and influenced by diet and other factors, it’s best to consult a healthcare provider before pursuing genetic testing, especially if you have related symptoms or a family history, so they can guide appropriate testing and treatment if needed.