Phase II Detoxification commentary is provided only for polymorphisms with known health implications.

+- NAT2     R197Q

Health Implications: N-acetyltransferase 1 is found in extra-hepatic tissues, while NAT2 is found predominantly in the liver and the gut. Both are used in the Phase II acetylation of numerous environmental toxins, including heterocyclic aromatic amines. Slow acetylators do not clear toxins well and the resulting increased total toxic burden can increase the risk of lung, colon, breast, bladder, and head and neck cancers, though results have not been consistent in all studies. Urinary bladder cancer appears top have the most consistent association with slow acetylation.

Minimizing Risk: If you smoke, stop. Your risk of lung cancer is substantially higher than someone with normal NAT activity. Even occasional smoking or exposure to second hand smoke is harmful. Liberal consumption of most vegetables and fruits but especially cruciferous vegetables (broccoli, Brussels sprouts, cauliflower, watercress, and cabbage), garlic, onions, soy, grapes and berries will increase Phase II efficiency, including acetylation.

PRESENT GSTM1     1p13.3

- - GSTP1     I105V

Health Implications: Glutathione S-transferases (GST) are responsible for detoxifying certain products of oxidative stress and a variety of electrophilic xenobiotics and carcinogens such as solvents, herbicides, pesticides, polycyclic aromatic hydrocarbons, steroids, and heavy metals. GSTM1 is located primarily in the liver, whereas GSTP1 is located primarily in the brain and lungs.

The test indicates that the GSTM1 gene is present, although it is not clear whether the gene is present on one or both chromosomes. This suggests normal GSTM1 enzyme activity and hepatic detoxification of xenobiotics and toxic metals.

GSTP1 polymorphisms are associated with either higher or lower enzyme activity, depending on the exposure. Although this I105V genotype is associated with less overall risk, it has still been associated with slightly increased risk of some cancers (especially with cigarette smoke exposure), atopy, xenobiotic-induced asthma, and COPD.

Minimizing Risk: Regardless of genotype, increasing the body's production of glutathione (GSH) will reduce oxidative stress and afford greater protection against a wide array of toxins. GSH precursors and cofactors include methionine, N-acetylcysteine, glutamine, glycine, magnesium, and pyridoxal-5-phosphate (B6). Allium vegetables (e.g., onions, leeks, garlic) and cruciferous vegetables (e.g., broccoli, cauliflower, cabbage) can increase GST activity. Most importantly, minimize exposure to cigarette smoke, charred food, herbicides, fungicides, insect sprays, industrial solvents, and toxic metals.