Do not perform genetic testing for polymorphisms in genes involved in detoxification processes for the diagnosis of Multiple Chemical Sensitivity (MCS)

Type of practice

Laboratory tests



Topic Area

Human Genetics

Multiple Chemical Sensitivity Syndrome (MCS) or Idiopathic Environmental Intolerance to Chemical Agents (IIAAC) is a chronic disorder, affecting multiple organs and systems, with a response to exposure to chemicals at lower levels than those generally tolerated by the general population. To date, there are no solid benchmarks for the diagnosis of this pathology, there is also a lack of functional tests able to explain signs and symptoms. Epidemiological studies conducted on the correlation between MCS syndrome and genetic polymorphisms involved in the detoxification process are still insufficient in number but, above all, conflicting with each other also with regard to the importance of the component of genetic variability rather than epigenetic or expression. Therefore, taking into account the international scientific literature, to make the diagnosis of MCS, there is insufficient evidence for the use of genetic tests aimed at typing metabolic polymorphisms P450 (CYP) 2E1, glutathione S-transferase (GST) M1, GSTT1, GSTP1).
Good practice: inform patients about the unreliability of the correlation between the above polymorphisms and MCS.


1. Consiglio Superiore di Sanità, 25 settembre 2008
2. MCS attività del gruppo di lavoro sulla intolleranza idiopatica ambientale ad agenti chimici (IIAAC) denominata anche sensibilità chimica multipla (SCM).
3. Dantoft TM Skovbjerg S, Andersson L, Claeson A, Engkilde K, Lind N Nordin S, Hellgren L. Gene expression profiling in persons with multiple chemical sensitivity before and after a controlled n-butanol exposure session. BMJ Open. 2017 Feb 22;7(2):e013879.
4. Cui X1, Lu X, Hiura M, Oda M, Miyazaki W, Katoh T. Evaluation of genetic polymorphisms in patients with multiple chemical sensitivity. PLoS One. 2013 Aug 13;8(8):e73708.
5. Rossi S, Pitidis A 2018 Multiple Chemical Sensitivity: Review of the State of the Art in Epidemiology, Diagnosis, and Future Perspectives.J Occup Environ Med. 2018 Feb;60(2):138-146.
6. D'Attis S, Massari S, Mazzei F, Maio D, Vergallo I, Mauro S, Minelli M, Bozzetti MP. Assessment of CYP2C9, CYP2C19, and CYP2D6 Polymorphisms in Allergic Patients with Chemical Sensitivity. Int Arch Allergy Immunol. 2019 Apr 3:1-14. doi: 10.1159/000497322.



Attention. Please note that these items are provided only for information and are not intended as a substitute for consultation with a clinician. Patients with any specific questions about the items on this list or their individual situation should consult their clinician.