Work in multiple laboratories on paraoxonase polymorphism has shown that this mammal enzyme protects against chlorpyrifos and other organophosphates differentially, depending on which inherited forms of the enzyme predominate. This variable ability to process pesticides exists in humans and is trackable ethnically (1), and very recent articles have suggested the polymorphism may be responsible for host susceptibility to Gulf War syndrome (2,3). Because my own interest is in multiple chemical sensitivity (MCS) mechanisms, I immediately searched Medline (National Library of Medicine, Bethesda, MD) for publications that included paraoxonase and MCS, fibromyalgia, or chronic fatigue syndrome (CFS), which have been suggested as being overlapping or identical with each other and with Gulf War syndrome (4,5). I found no other references at all.
You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1566473/pdf/envhper00513-0015b.pdf
Source: Rowat SC. Paraoxonase/MCS. Environ Health Perspect. 1999 Aug;107(8):A395. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1566473/pdf/envhper00513-0015b.pdf