Use of test
Mutations in the SERPING1 gene cause hereditary angioedema (HAE) type I and type II. 85% of patients have low serum levels of C1 esterase (HAE type I); the remainder have normal C1 esterase levels but the protein is non-functional (HAE type II). The two types are clinically indistinguishable. This condition is inherited in an autosomal dominant pattern.
In an affected patient, an abnormal result is diagnostic of HAE. A normal test result makes the clinical diagnosis unlikely but does not exclude it.
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.
Download the Sonic Genetics consent form.
DNA sequencing of SERPING1 gene.
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.
10 business days.
This test is not rebated by Medicare. The laboratory assumes that the patient or client has provided informed financial consent for the test.