The TERT gene provides instructions for making one component of an enzyme called telomerase. Telomerase maintains structures called telomeres, which are composed of repeated segments of DNA found at the ends of chromosomes. Telomeres protect chromosomes from abnormally sticking together or breaking down (degrading). In most cells, telomeres become progressively shorter as the cell divides. After a certain number of cell divisions, the telomeres become so short that they trigger the cell to stop dividing or to self-destruct (undergo apoptosis). Telomerase counteracts the shortening of telomeres by adding small repeated segments of DNA to the ends of chromosomes each time the cell divides.
In most types of cells, telomerase is either undetectable or active at very low levels. However, telomerase is highly active in cells that divide rapidly, such as cells that line the lungs and gastrointestinal tract, cells in bone marrow, and cells of the developing fetus. Telomerase allows these cells to divide many times without becoming damaged or undergoing apoptosis. Telomerase is also abnormally active in most cancer cells, which grow and divide without control or order.
If you carry the T-allele in this gene, you may be predisposed to breast cancer and other cancers but this should be viewed in conjunction with other cancer genes. Following a diet high in vitamin A (tretinoin) and isothiocyanates is important for decreasing TERT activity. Foods rich in vitamin A include cod liver oil, eggs, yellow and orange fruit and vegetables, and dark leafy green vegetables. You can also add in a supplement containing vitamin A. Foods high in isothiocyanates (sulforaphane and glutathione) include can be found in cruciferous vegetables. However, you may wish to supplement these compounds. Considered this genotype in conjunction with your GSTM1, GSTT1, and GSTP1 genotypes. It is also important to check and manage your estrogen levels and type of estrogens as research has shown that estrogen can increase TERT activity.