DNA damage

Telomere

Genome instability

Transcription factor

Biology

Telomerase

Gene

Protein aggregation

Telomere-binding protein

Proteotoxicity

DNA-binding protein

Genetics

Nature Reviews Genetics

Telomeres are specialized nucleoprotein structures at the ends of linear chromosomes that prevent the activation of DNA damage response and repair pathways. Numerous factors localize at telomeres to regulate their length, structure and function, to avert replicative senescence or genome instability and cell death. In humans, Mendelian defects in several of these factors can result in abnormally short or dysfunctional telomeres, causing a group of rare heterogeneous premature-ageing diseases, termed telomeropathies, short-telomere syndromes or telomere biology disorders (TBDs). Here, we review the TBD-causing genes identified so far and describe their main functions associated with telomere biology. We present molecular aspects of TBDs, including genetic anticipation, phenocopy, incomplete penetrance and somatic genetic rescue, which underlie the complexity of these diseases. We also discuss the implications of phenotypic and genetic features of TBDs on fundamental aspects related to human telomere biology, ageing and cancer, as well as on diagnostic, therapeutic and clinical approaches. Mendelian defects in genes encoding factors that regulate telomere length, structure and function cause telomeropathies, or telomere biology disorders (TBDs). The authors review confirmed as well as potential TBD-causing genes and their main functions in telomere biology. They also discuss genetic features that underlie the complex nature of these diseases.

Genetics of human telomere biology disorders