A Rare Case of Cerebral Sinovenous Thrombosis Associ at ed with MTHFR A1298C and C677T Mutations

Neonatal cerebral sinovenous thrombosis (CSVT) is a rare disease with severe neu­ rological sequelae. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the folate cycle, and mutations in MTHFR are associated with vascular diseases. Here, we report the case of a newborn with MTHFR mutation­associated CSVT. Analysis of MTHFR in the patient detected heterozygous C677T (677CT) and A1298C (1298AC) mutations. Analysis of MTHFR in the patient's mother did not detect a C677T (677CC) mutation but detected a homozygous A1298C (1298CC) mutation. Our results suggest that the presence of heterozygous MTHFR C677T and A1298C mutations affect thrombophilic activity in the neonate, resulting in the development of refractory seizure and CSVT. Moreover, presence of the homozygous MTHFR A1298C mutation in the patient's mother, who did not show any symptoms associat­ ed with thrombophilic activity, and conditions during gestation may have affected the patient's condition.