Genetic susceptibility factors for multiple chemical sensitivity revisited

Int J Hyg Environ Health. 2010 Mar;213(2):131-9. doi: 10.1016/j.ijheh.2010.02.001. Epub 2010 Feb 24.


Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. Various genes, especially genes of importance to the metabolism of xenobiotic compounds, have been associated with MCS, but findings are inconsistent. The purpose of this study was to investigate genetic susceptibility factors for MCS and self-reported chemical sensitivity in a population sample. Ninety six MCS patients and 1,207 controls from a general population divided into four severity groups of chemical sensitivity were genotyped for variants in the genes encoding cytochrome P450 2D6, arylamine N-acetyltransferase 2, paraoxonase 1, methylene tetrahydrofolate reductase, and the cholecystokinin 2 receptor. No hypotheses were consistently confirmed. An apparent association between number of active cytochrome P450 2D6 alleles and MCS status was not statistically significant (OR=1.2, p=0.28). Fast arylamine N-acetyltransferase 2 metaboliser status was associated with severity of chemical sensitivity only in the most severely affected group in the population sample (OR=3.1, p=0.04). The cholecystokinin 2 receptor allele with 21 CT repeats was associated with MCS when compared in post hoc analyses with all individuals from the population sample (p=0.02). Genetic variants in paraoxonase 1 and methylene tetrahydrofolate reductase were not associated with MSC or with self-reported chemical sensitivity in the population sample. Our results suggest that variants in the genes examined are of less importance to MCS than previously reported or that gene-environment interactions or significant degrees of genetic heterogeneity in MCS underlie inconsistent findings in the literature.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arylamine N-Acetyltransferase / genetics*
  • Aryldialkylphosphatase / genetics*
  • Case-Control Studies
  • Cytochrome P-450 CYP2D6 / genetics*
  • Female
  • Genetic Predisposition to Disease
  • Humans
  • Male
  • Methylenetetrahydrofolate Reductase (NADPH2) / genetics*
  • Middle Aged
  • Multiple Chemical Sensitivity / genetics*
  • Receptor, Cholecystokinin B / genetics*
  • Young Adult


  • Receptor, Cholecystokinin B
  • Cytochrome P-450 CYP2D6
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • Arylamine N-Acetyltransferase
  • NAT2 protein, human
  • Aryldialkylphosphatase
  • PON1 protein, human