Also known as:Apolipoprotein E genotyping, hyperlipoproteinaemia
Familial - Hyperlipidaemia, Cardiac
Use of test
The Apolipoprotein E gene (APOE) plays a critical role in lipid metabolism. Variants of this gene are associated with some clinical disorders of lipid metabolism or with clinical outcomes associated with such disorders.
For a patient with increased plasma cholesterol and triglycerides, this test can be a diagnostic test for type III hyperlipoproteinaemia as more than 90% of patients with this condition have two copies of the E2 variant.
The E4 variant is associated with raised low-density lipoproteins (LDL) and has an association with Alzheimer disease and atherosclerosis.
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. Use of the Sonic Genetics consent form (below) is not mandated, but could be used to guide the discussion with the patient.
In the case of carrier testing of an unaffected child, national regulations require that the laboratory has evidence of pre-test counselling by a genetics professional and written consent.
Analysis of the APOE gene for E2, E3, and E4 variants. Variants in the APOE gene other than E2, E3 and E4 will not be detected by this test.
Requesting the test
This test can be requested by any medical practitioner.
4 mL blood in EDTA (separate tube required). 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.