What is a telomere biology disorder (or telomeropathy)?

What is Telomere Biology Disorder word cloud

There are multiple different terms for telomere biology disorders, here we explain what they are and what conditions they can encompass.

Telomere biology disorders

Telomere biology disorders (TBDs) are a complex set of conditions defined by genetic deficits affecting telomere maintenance and by the presence of very short telomeres. These disorders can also be referred to as short telomere syndromes or telomeropathies.

Telomeres naturally shorten as we age, however, in some individuals the length is abnormally short or the shortening process is accelerated (in some cases both issues can occur). When telomeres become critically short, cells can no longer divide effectively.

There are 15 known genes which can experience damaging mutations, or other abnormalities, that can cause very short telomeres (for example the telomerase genes TERC and TERT). Nevertheless, there are still a number of cases where no currently known, or new, gene abnormality affecting telomere function can be found, despite the presence of very short telomeres.

TBDs can impact any organ in the body – which is why symptoms and disease presentation can vary from individual to individual. Watch this animated video to learn more about the possible symptoms of TBDs:

Dyskeratosis congenita, is a serious TBD which is normally diagnosed in childhood as symptoms typically occur earlier in life. Conversely, there are those who are diagnosed in later adulthood, with conditions such as pulmonary fibrosis or myelodysplastic syndromes. It is also possible to be a carrier for a TBD related genetic mutation, without experiencing symptoms that require medical intervention.

How to measure telomeres?

As TBDs are defined by the presence of short telomeres in the great majority of cases, having the ability to measure telomere length is of great importance.

This is where we come in. At RepeatDx we use a complex but well-established process called Flow FISH (fluorescence in situ hybridization with flow cytometry). From a standard blood sample, we can provide accurate telomere length measurements. These are then compared to an age-matched control group and categorized on a scale from Very Low (<1st percentile) to Very High (≥99th percentile).

The sensitivity and specificity for Flow FISH telomere length analysis have been defined for the clinical diagnosis of DC.

You can read more about what Flow FISH testing is in a separate blog.

To find out more about what telomeres are and how they function take a look at this blog.

Sources
Savage, S. A. and Bertuch, A. A. The genetics and clinical manifestations of telomere biology disorders. Genetics in medicine: Official Journal of the American College of Medical Genetics. vol. 12,12 (2010): 753-64. doi:10.1097/GIM.0b013e3181f415b5.
Savage, S. & Cook, E. Dyskeratosis Congenita and Telomere Biology Disorders: Diagnosis and Management Guidelines. (First ed.) 2015. Accessed at: https://teamtelomere.org/wp-content/uploads/2018/07/DC-TBD-Diagnosis-And-Management-Guidelines.pdf.
Townsley, D. M. et al. Bone marrow failure and the telomeropathies. Blood. vol. 124,18 (2014): 2775-83. doi:10.1182/blood-2014-05-526285.