Telomeres and Telomerase Deficiency

Telomere disorders are caused by extremely short telomeres. When telomeres become extremely short, cells can no longer divide effectively. An inherited mutation in the gene that produces the telomere lengthening enzyme called telomerase disables the enzyme and causes telomeres to shorten at a faster rate.

RepeatDx’s procedure has been shown to be a valuable screening test for inherited telomere maintenance deficiencies. This interest is driven by several recent peer-reviewed scientific publications showing that telomere length analysis measured by FlowFISH can be used to identify individuals with various forms of inherited telomerase deficiency and to distinguish carriers of mutations in telomerase genes and in genes encoding telomere binding proteins from individuals without such abnormalities. More information on RepeatDx and our FlowFISH technology can be found in the FAQ section.

Inherited deficiencies where telomere maintenance is used in diagnosis include bone marrow failure, dyskeratosis congenita, immune deficiencies, pulmonary fibrosis and cardiovascular diseases.

Dyskeratosis Congenita

The clinical sensitivity and specificity for FlowFISH telomere length analysis have been defined for the diagnosis of dyskeratosis congenita.

  • Telomere biology disorders, an inherited genetic condition, is associated with Low (L) or Very Low (VL) leucocyte telomere length in several leucocyte subsets in the presence of specific symptoms and/or significant family history.
  • No critical values have been defined outside this specific clinical application (telomere biology disorders) to date.
  • Research reports published in the scientific and medical literature point to other potentially clinically valuable applications (for which critical values have not been formally established).

A guideline for the diagnosis and management of Dyskeratosis Congenita and Telomere Biology Disorders and edited by Drs. Sharon A. Savage and Elizabeth F.Cook can be found on the Team Telomere website.

Pulmonary Fibrosis

Pulmonary fibrosis (PF) has been linked molecularly by abnormal telomere maintenance. Studies have found that Very Low leukocyte telomere length is independently associated with worse survival for PF patients. Reasons for testing include:

  • Diagnostic tool for patients and family with familial and idiopathic pulmonary fibrosis
  • Telomere length is associated with transplant free survival and can aid in disease course prediction.
  • Ability to avoid the potential complications of lung biopsies in high risk patients
  • Aid in disease course prediction
  • Risk assessment for lung transplantation
  • Cost of FlowFISH telomere test is less than TERT and TERC genetic testing and has faster turn around time

Bone Marrow Donors Screening

Findings have indicated that telomere length shortens rapidly in patients immediately following hematopoietic stem cells transplantation.

  • Findings suggest that it is important to identify donors with healthy telomere maintenance that are within the biologically tolerable range of the recipient.
  • If hematopoietic stem cells from older telomere maintenance deficient donors are transplanted into younger patients, the telomeres may become too short resulting in cellular senescence and bone marrow failure.

Coronary artery disease

Telomere shortening plays a crucial role in the pathogenesis of aging-associated CAD.

  • Short telomeres can lead to cellular senescence and apoptosis, which contribute to the development of atherosclerosis and predispose people to plaque instability.
  • Both genetic and environmental factors have been associated with individual variations in telomere length.
  • Cardiovascular risk factors such as smoking, diabetes mellitus, hypertension, obesity, sedentary lifestyle, and stress have been considered to increase oxidative stress or inflammation, consequently accelerating TL shortening.


RepeatDx provides telomere testing for individual who, under physician supervision, may be interested in adding telomere length measurements as a biomarker for monitoring other diseases or family history risks. Due to regulator requirements, RepeatDx cannot provide diagnostic testing direct to consumers. Before acquiring a blood sample, the requisition form must to be reviewed and signed by a practicing licensed physician. RepeatDx does not recommend or approve treatments designed to optimize telomere modifications.

For patients and families wanting more information on telomere biology disorders, visit the Team Telomere website.