Increased Neurotoxicity of Arsenic in Methylenetetrahydrofolate Reductase Deficiency

Clin Neurol Neurosurg. 1992;94(4):307-10. doi: 10.1016/0303-8467(92)90179-7.


A 16-year-old girl from Surinam presented with mental deterioration and severe paraparesis with areflexia and bilateral Babinski signs. Laboratory examination showed a hyperhomocysteinemia that was caused by 5,10-methylene-tetrahydrofolate reductase (MTHFR) deficiency. In addition, urine samples contained large amounts of arsenic. An open bag with the pesticide copper acetate arsenite was found to be the source of exposure. In remethylation defects such as MTHFR deficiency, the concentration of methyldonors is severely reduced. As arsenic is detoxified by methylation, we suggest that the MTHFR deficiency in this girl might explain the fact that of all family members exposed to arsenic, only she developed severe clinical signs and symptoms of arsenic poisoning.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Arsenic / pharmacokinetics
  • Arsenic Poisoning*
  • Arsenites*
  • Female
  • Homocysteine / blood*
  • Humans
  • Intelligence / drug effects
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • Nervous System Diseases / chemically induced*
  • Nervous System Diseases / enzymology
  • Neurologic Examination / drug effects
  • Neuropsychological Tests
  • Oxidoreductases Acting on CH-NH Group Donors / deficiency*
  • Tomography, X-Ray Computed


  • Arsenites
  • Homocysteine
  • Oxidoreductases Acting on CH-NH Group Donors
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • arsenite
  • Arsenic