Use of test
Hypertriglyceridaemia is usually due a combination of multiple genetic and environmental factors i.e. "polygenic hypertriglyceridaemia", and genetic testing has little role to play in the management of such families.
There is a small important group of hypertriglyceridaemias that are due to mutations in any one of several genes i.e. these are single-gene disorders. This group includes hyperchylomicronaemia, hyperlipoproteinemia (type Ib), hyperlipoproteinemia (type 1d), apolipoprotein C-III deficiency, infantile hypertriglyceridaemia, combined lipase deficiency, lipoprotein lipase deficiency, and familial combined hyperlipidaemia.
The diagnosis of a specific familial dyslipidaemia is made on the basis of clinical history and biochemical findings. Genetic testing is not necessary to make this diagnosis.
This test result has implications regarding the aetiology and inheritance of dyslipidaemia in an individual, and the risk of dyslipidaemia and related disorders in a patient's relatives.The interpretation of the result may be dependent on the family history and the interpretation of other studies.
In patients with familial lipoprotein lipase deficiency, a pathogenic mutation can be identified in more than 95% of cases.
In an affected person with a clinical diagnosis, the presence of a pathogenic mutation confirms the diagnosis and may provide additional information regarding the risk of the disorder in relatives. However, the absence of a pathogenic mutation in such a patient does not necessarily exclude the clinical diagnosis.
In an unaffected person from a family with confirmed genetic diagnosis, the presence of the family's mutation may indicate an increased risk of developing atherosclerosis, and close clinical follow-up may be warranted. The interpretation of such results depends on the particular gene and mutations. Pre-test genetic counselling is strongly recommended.
This is an assay for heritable mutations. It may raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient. Pre-test genetic counselling and written consent are required, and are provided through Sonic Genetics at no additional cost (see Cardiac genetic counselling for details).
This test can assist in making a diagnosis in an affected patient. It may also provide useful risk information for unaffected relatives. Testing unaffected people to provide risk information may require that the clinician comply with guidelines provided by professional and regulatory authorities regarding pre-test counselling and consent. In particular, national regulations stipulate that carrier testing of an unaffected child requires the laboratory to have evidence of pre-test counselling by a genetics professional and written consent. For advice or assistance, please contact us on 1800 010 447.
Consent managed by genetic counsellor.
Analysis of a gene panel for sequence abnormalities and deletions/duplications.
For an updated list of genes included in the panel please click here.
Requesting the test
This test is usually requested by a medical specialist with experience in the genetic management of dyslipidaemias, or a clinical geneticist.
Download the cardiac genetics diagnostic test request form.
2-5 mL blood in EDTA. Specimens may be collected by the requesting practitioner or at any Sonic Healthcare collection centre (see link below).
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We recommend that the patient or another adult check the labelling of request forms and sample tubes.
Please include a statement about family history (or absence of family history) of the disease in clinical details on referral form. If family history is present, please state relationship to patient.
This is the price for initial genetic testing of an affected person. Once a family's mutation is identified, targeted mutation analysis can be offered to family members; please contact Sonic Genetics on 1800 010 447 or at email@example.com regarding price and turn-around time.
This test is not rebated by Medicare. The laboratory assumes that the patient or client has provided informed financial consent for the test.