Our Services - Predictive Testing by SNG or MLPA
What is Predictive Testing?
Genetic ‘predictive testing’ is, by definition, testing in an individual that does not show signs or symptoms of the disorder for which the testing is targeting. This is also known as ‘presymptomatic testing’.
This type of testing has a high level of risk for the patient and laboratory. Returning a false negative result to the patient can lead to the patient not receiving appropriate care and is a legal risk for the laboratory. Returning a false positive test can also lead to unnecessary anxiety and treatment for the patient (and family). Hence, there are several stringent requirements that must be adhered to when doing this type of genetic testing.
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Predictive testing can be done using either Sanger Sequencing (SNG) or Multiplex Ligation-dependent Probe Amplification (MLPA). For more information on these testing methods, please visit their respective pages.
Pre and Post Testing Requirements
- Predictive testing will only be done on ACMG Class 4 (Likely Pathogenic) or Class 5 (Pathogenic) DNA variants. ACMG Class 4 (Likely Pathogenic) test results must clearly convey the degree of uncertainty about the link between the particular DNA variant/s being tested and the disorder phenotype including known (published) degrees of incomplete penetrance and variability of expression.
- Predictive testing will only be done on medical conditions with sufficient clinical importance to warrant presymptomatic testing as determined by the treating team including clinical geneticist. CCG is not accredited for and does not do pre-natal testing.
- Testing will only be done on individuals 16 years or over unless there is a compelling medical reason for early treatment/intervention. Testing for under 16 years of age patients must be in consultation with a clinical geneticist, treating physician and with parents/guardians informed consent.
- Pre-test genetic counselling of the patient is required. Predictive tests constitute level 2 NPAAC DNA tests. Written confirmation of pre-test counselling must be received by the laboratory prior to testing.
- The final report will be sent to the clinical genetics team for post-test counselling and release of results. The treating physician may need to be available when the results are conveyed.
Request Form
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Please ensure you provide the specific location of the target base(s). For the sequencing of symptomatic patients, or unaffected family members, please use the Sanger Sequencing and MLPA request form. For the sequencing of whole genes or gene families, please use the Whole Genome Sequencing request form.
Turn-Around Time
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2-4 weeks
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Please note: TATs are dependant on the receipt of a completed test request form (including consent) and specimen(s).
Cost
All testing done through Canberra Clinical Genomics is free for ACT and surrounding residents and their family members.
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Currently, no paid services are available to residents outside the ACT and surrounding area so eligibility is essential.