Can you measure telomeres; and why would you want to?

Telomere biology research is a growing and advancing field, but still people ask ‘can you actually measure telomere length?’ Here we answer this key question and also address how these telomere measurements can be useful.

Can you measure telomeres?

Yes. There are a number of different ways to measure telomere length, all with varying degrees of accuracy and different requirements.

Telomeres are the protective caps on the ends of chromosomes, and over the last two decades, new methods for measuring their length have been developed. For example, Terminal Restriction Fragment (TRF), Quantitative Fluorescence In Situ Hybridization (Q-FISH), Fluorescent In Situ Hybridization with Flow Cytometry (Flow FISH), and Quantitative Polymerase Chain Reaction (q-PCR).

These methods have been refined and improved over the years, and there are now a number of techniques that have been validated in clinical studies. Competition remains between measurement methods. However, they each have different strengths and weaknesses, and are best suited to different situations. Flow FISH is the only test methodology to date that is recommended by expert physicians for the clinical diagnosis of telomere biology disorders (TBDs).

Watch this short video to learn more about telomeres and how they can be measured.

Why measure telomeres?

Telomeres are a fundamental biomedical variable in aging as well a number of diseases including rare genetic conditions and cancer. Accurate and reproducible telomere length measurements can therefore be used by physicians to support diagnosis and disease management of a range of medical conditions.

Telomere length can play a role in identifying the cause of disease and can inform treatment selection and prognosis in conditions such as dyskeratosis congenita (and other TBDs), idiopathic pulmonary fibrosis, myelodysplastic syndromes and liver disease.

Telomere length analysis has also been the object of keen interest as a way of providing personal biological aging information. However, this has not been studied in controlled clinical studies that would be necessary to responsibly guide the interpretation of results.

Are telomere tests used now by physicians?

Yes. RepeatDx’s Flow FISH procedure is a valuable screening test for inherited TBDs and is currently being used in clinical practice. The clinical sensitivity and specificity for Flow FISH telomere length analysis have been defined for the diagnosis of dyskeratosis congenita and pulmonary fibrosis mediated by TBD. Thus, samples are sent by physicians from around the world to be tested at the RepeatDx lab.

There are also other, newer, clinical applications for telomere testing. Clinical research has shown that very low telomere length is independently associated with worse survival for pulmonary fibrosis patients, even in the absence of a TBD.

It can be important that telomere length is measured prior to bone marrow / stem cell transplantation. Especially in cases of a related donor transplant to an individual with a TBD or other heritable disease. Read more about testing prior to transplant in this blog.

With research ongoing, and data being regularly published, it seems that the clinical uses of accurate and reliable telomere testing will continue to grow.

You can see some of the key benefits of telomere length testing summarized in this infographic.

If you want to order a telomere length test from RepeatDx, you can download the required requisition form and watch a short informative video on sample preparation and shipment here.

Sources

Alder, J. et al. Diagnostic utility of telomere length testing in a hospital-based setting. Proceedings of the National Academy of Sciences of the United States of America. Vol. 115,10 (2018): E2358-E2365. doi:10.1073/pnas.1720427115.

Aubert, G. et al. Telomere length measurement-caveats and a critical assessment of the available technologies and tools. Mutation Research. Vol. 730,1-2 (2012): 59-67. doi:10.1016/j.mrfmmm.2011.04.003.

Ferreira, M. S. et al. Comparison of flow‐FISH and MM–qPCR telomere length assessment techniques for the screening of telomeropathies. Annals of the New York Academy of Sciences. 2019. doi:10.1111/nyas.14248.

Gutierrez-Rodrigues F. et al. Direct Comparison of Flow-FISH and qPCR as Diagnostic Tests for Telomere Length Measurement in Humans. PLoS ONE. 9(11): e113747 (2014). https://doi.org/10.1371/journal.pone.0113747.

Planas‐Cerezales, L. et al. Predictive factors and prognostic effect of telomere shortening in pulmonary fibrosis. Respirology. 2018. doi:10.1111/resp.13423.

Rollison, D. et al. Telomere length in myelodysplastic syndromes. Leukemia & Lymphoma. Vol. 52,8 (2011): 1528-36. doi:10.3109/10428194.2011.568648.

Savage, S. and Bertuch, A. The Genetics and Clinical Manifestations of Telomere Biology Disorders. Genet Med. 2010 December. 12(12). 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

van der Harst, P. et al. Telomere Length of Circulating Leukocytes Is Decreased in Patients With Chronic Heart Failure. Journal of the American College of Cardiology. Volume 49, Issue 13, 3 April 2007. doi:10.1016/j.jacc.2007.01.027.