CRYPTOGENIC ISCHEMIC STROKE IN A YOUNG ADULT ASSOCIATED WITH MTHFR GENE POLYMORPHISMS: A CASE REPORT

Background:- Ischemic stroke in young adults requires comprehensive etiological investigation because of the wide range of potential underlying mechanisms. Hyperhomocysteinemia has been associated with cerebrovascular risk, while the clinical significance of common methylenetetrahydrofolate reductase (MTHFR) variants remains debated. Case Presentation:- A 23-year-old man with no significant medical history was admitted for sudden - onset headache, vertigo, balance disturbances, and left-sided hemiplegia. Brain computed tomography and magnetic resonance imaging revealed an acute left cerebellar infarction in the territory of the posterior inferior cerebellar artery (PICA), with collateral vascular circulation and a small petechial hemorrhagic transformation. Cardiac investigations, vascular imaging, and testing for selected thrombophilic and autoimmune conditions did not identify a definitive conventional cause. Genetic testing was negative for the factor V Leiden (F5) and prothrombin (F2) G20210A variants. Analysis of MTHFR identified homozygosity for the A1298C variant and no detectable C677T variant. Plasma homocysteine was elevated.