Methylene Tetrahydrofolate Reductase Deficiency: the Hidden Risk in Paediatric Anaesthesia

Methylene tetrahydrofolate reductase (MTHFR) deficiency is an autosomal recessive disorder that results in increased homocysteine levels in the body. Hyperhomocysteinemia causes a predisposition to venous and arterial thrombosis and ischaemic insults. The incidence of the deficiency is around 40% in some countries. In this study, we aimed to evaluate the effects of anaesthetic agents in children with MTHFR deficiency.

Twelve paediatric patients with an MTHFR enzyme deficiency who underwent surgery in a ten-month period in a single centre were retrospectively evaluated. Demographic data, homocysteine levels before and after surgery, anaesthesia management and postoperative complications were recorded.

In four patients, propofol was used both for anaesthesia induction and total intravenous anaesthesia (TIVA). Eight patients received sevoflurane for both induction and maintenance of anaesthesia. Nitrous oxide (N₂O) was not used in any patients. There was not a significant difference between the preoperative and postoperative homocysteine levels (p>0.05). Twenty-four hours after the surgery, the homocysteine levels were within normal limits. No complications were observed.

Sevoflurane and propofol have no deleterious effects on homocysteine levels in patients with MTHFR deficiency. Avoidance of N₂O is the key point for anaesthetic consideration regarding these patients.