Telomere length: is the future in our “ends”?

Telomeres, repetitive nucleotide sequences located at the end of each chromosome, play the important function of preserving chromosome stability and preventing molecular contact with neighboring chromosomes. Albeit the concept that telomere length may be a marker of health and disease seems hence counterintuitive, the translation of this clear-cut concept from the bench to the beside has appeared so far less straightforward. In particular, controversial evidence has emerged so far about the fact that telomere length may actually predict morbidity and mortality across many clinical settings. This uncertainty is actually due to a kaleidoscope of biological and technical factors, including preanalytical issues (e.g., sample matrix), poor standardization of techniques used for their assessment, and dependence of telomere structure upon genetics, epigenetics, environment and behavioral attitudes, which may be present at a variable extent in various physiological or pathological conditions. Therefore, although it is now undeniable that our future is largely in our “hands” (i.e., genotype, diet, exposure to environmental factors and so forth), larger and more solid evidence will be necessary before concluding that the future is also written in our (chromosome) “ends”.