Telomere length testing is indicated in the diagnosis of Dyskeratosis congenital (DC) and other telomere biology disorders (telomeropathy). All individuals with DC have abnormally short telomeres for their age, as determined by flow cytometry fluorescence
in situ
hybridisation (flow-FISH) on white blood cell subsets. Telomere length less than the first percentile for age in lymphocytes is 97% sensitive and 91% specific for DC.
A telomeropathy should be considered in all patients with Aplastic Anaemia, hypoplastic MDS as well as in patients who have long-standing cytopenias, including unexplained thrombocytopenia or when there is suggestive personal and family history (for example - AA, AML, MDS, pulmonary fibrosis, cytogenic cirrhosis, leukoplakia, abnormal skin pigmentation, nail dystrophy). Testing should be performed when treatment decisions may be affected, and after ruling out Fanconi anaemia.
Telomere length measurement is available via Westmead, Australia. Please see below for instructions on ordering this test, complete the form and email to Westmead.
Specimen Collection
Specimen Requirements:
Adult and Paediatric referrals: A minimum of 6-8mL of whole blood (or 15-20mL if the WCC < 2x10
9
/L) in a Lithium Heparin tube without gel
AND
1-2mL blood in an EDTA tube without gel.
Specimen Transport:
The specimen must be kept at room temperature
at all times
- even brief periods of freezing or cooling will affect the results. Specimen must arrive at Westmead lab within 24-36 hours of specimen collection.
Referral Requirements:
Testing is performed once a week at Westmead laboratory on a Wednesday.
The requesting Doctor
MUST
contact Westmead lab the week before collecting the sample and requesting the test, and email through a completed referral form to book the sample in for testing with Westmead lab directly. Following confirmation of booking from Westmead, contact LabPlus Specimen Reception on the preceding Friday to notify the International Sendaway team that a sample will be arriving for testing the following Monday.
The sample must be collected on Monday morning, and arrive at LabPlus before 11am.
1 mL Adult EDTA Whole Blood
6 mL Adult 2xHeparin Whole Blood
Turnaround Time: At least 1 week, 5 days