Abstract
Methylenetetrahydrofolate reductase (MTHFR) disease is a disorder in which reduced activity of the MTHFR enzyme disrupts folate and homocysteine metabolism, causing elevated homocysteine levels. Patients with MTHFR mutation suffer many serious lifelong complications. Our case presents a 37-year-old male who was diagnosed with a heterozygous subtype of MTHFR. He suffered multiple life-threatening blood clotting episodes despite being on adequate anticoagulants. His management was challenged by the complexity of his disease progression, as well as limited literature and clinical guidelines on the management of this condition. This unique case report adds to the understanding of clinical manifestations and acute management strategies for patients with heterozygous MTHFR mutations who suffer excessive clotting as a complication.