By Fatin Chowdhury ‘19
Telomeres are regions of repeated nucleotide sequences at the ends of chromosomes; while they are valuable for protecting chromosomal ends from deterioration or fusion with the ends of neighboring chromosomes, their roles among medical treatments have been mainly unknown. A recent study led by Dr. Jonathan K. Alder of The Johns Hopkins School of Medicine analyzed telomere length value and aimed to determine whether telomere length (TL) could be utilized in hospital-based diagnoses. The study was formulated with special attention to medical cases such as short telomere syndromes and idiopathic bone marrow failure.
To conduct this study, the researchers used 192 control subjects and measured telomere length values with flow cytometry and in-situ hybridization techniques. The researchers examined whether TL could be used to pinpoint germline mutations in telomere upkeep, using 100 individuals who had families carrying pathogenic mutations in telomerase and telomere related genes. 38 patients younger than 40 years old participated in this study for the analysis of telomere lengths among patients with bone marrow issues.
The testing had negative predictive values for excluding mutation-carrying patients, and telomere lengths were similar for the asymptomatic and symptomatic groups. In a separate testing of 73 symptomatic mutation carriers, short telomere syndrome phenotypes were related to age. For the telomere lengths in patients with bone marrow issues, longer lymphocyte TL was more prevalent among changes in the immune system. Treatment changes, such as choosing a different hematopoietic stem cell donor, were made among 24% of the selected patients.
Future studies may continue to explore whether there is a role for genetic testing and DNA sequencing in clinical treatment of hospital patients. DNA mutations and quantitative data relating to telomeres are factors that, as suggested by the researchers, will remain subject to scientific investigation.
- J. K. Alder, et al., Diagnostic utility of telomere length testing in a hospital-based setting. Proceedings of the National Academy of Sciences 115, E2358-E2365 (2018). doi: 10.1073/pnas.1720427115.
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