The present invention relates to a cDNA probe for human methylenetetrahydrofolate reductase (MTHFR), and its uses. The probeof the present invention may be used for the identification of sequence abnormalities in patients with severe or mild MTHFR deficiency,including cardiovascular patients and patients with neurologic symptoms. A human MTHFR protein which hybridizes to the probe of thepresent invention may be used for therapy of MTHFR-deficiency patients by biochemical or pharmacological approaches.
