Telomeric diseases are a group of rare progeroid genetic syndromes, presenting premature
aging phenotypes, characterized for defects on telomere maintenance. In humans, telomeres are
heterochromatic structures consisting of long TTAGGG repeats located at the chromosomal ends,
which shorten progressively after each DNA replication because of the ‘end replication problem’.
Critically short telomeres activate a DNA damage response that leads to the arrest of the cell cycle and
resulting in cellular senescence or apoptosis. Furthermore, excessively short telomeres are prone to create telomeric
fusions, causing genomic instability and malignant transformation. In order to counteract this process, there are two
enzymatic complexes, the telomerase complex, with the capacity to elongate telomeres; and the shelterin complex, which
protects them from being recognized as DNA breaks. Over the last few decades, several studies have confirmed that
critically short telomeres and defects in telomere-associated enzymatic complexes are involved in the development of a
group of rare human genetic diseases, with the accumulation of excessive telomere attrition as the underlying cause of
these pathologies. Despite the severity of these disorders, there is no curative treatment for any of them. In light of this,
this review summarizes the most important defective telomere diseases, their current management, and it presents possible
therapeutic strategies based on nanotechnology which may open up new possibilities for their treatment.