A deletion results in an absence of the enzyme, leading to reduced capacity for hepatic detoxification and increases the likelihood that mutagenic DNA adducts will be produced. The GSTM1 null genotype is associated with increased risk of various cancers, chemical sensitivity, coronary artery disease in smokers, atopic asthma, and deficits in lung function.
If you have a deletion in this gene, then it is recommended that you minimize your exposure to toxins and pollutants such as cigarette smoke, pesticides, PAHs, acrylamides, etc. Ensure the diet is rich in antioxidants and substantially increase intake of cruciferous and allium vegetables to increase the activity of other GST enzymes. When dietary intake is inadequate a high-quality supplement containing DIM or sulforaphane may be required.