A telomere is a highly repetitive region, therefore a priori noncoding, if we consider the DNA at the end of a chromosome. Whenever a chromosome of a eukaryotic stick is duplicated, when replicating that precedes mitosis (cell division), the enzymatic complex of the DNA polymerase is unable to copy the last nucleotides : the absence of telomere could mean a rapid loss of genetic information necessary for the cell operation. Recent studies suggest however that the repetitive DNA of telomeres might be transcribed into repetitive RNA which may play a role in stabilizing telomere.
Telomeres shorten with age, inflammation and stress. Studies have shown that short telomeres are associated with a higher risk for diseases related to age.