Also known as: Thoracic aortic aneurysm, Lois-Dietz syndrome, Marfan syndrome, Ehlers-Danlos syndrome type 4, EDS type 4.« Back to test list
Thoracic aortic aneurysms can be a feature of familial connective tissue disorders which are diagnosed on clinical grounds, including Marfan syndrome, Lois-Dietz syndrome, and Ehlers-Danlos syndrome Type 4. They can also be due to familial mutations which are not associated with clinical features that would suggest a specific diagnosis.
On the other hand, abdominal aortic aneurysms are typically due to a combination of genetic and environmental factors, and genetic testing is not available.
The diagnosis of a familial aortopathy is made on the basis of clinical history, imaging, and family history. Genetic testing is not necessary to make this diagnosis.
This test result has implications regarding the aetiology and inheritance of familial aortopathy in an individual, and the risk of aortopathy and related disorders in a patient’s relatives.
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.
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.
A pathogenic mutation can be found in approximately 20% of patients with familial non-syndromic aneurysm or dissection of the thoracic aorta. In patients with a clinical diagnosis of Marfan syndrome, Lois-Dietz syndrome, or Ehlers-Danlos type 4, a pathogenic mutation can be found in 90-95% of patients.
In an affected person with a clinical diagnosis of a familial thoracic aortopathy, the presence of a pathogenic mutation confirms the diagnosis and may provide additional information regarding the risk of cardiac and non-cardiac manifestations in relatives. However, the absence of a pathogenic mutation in such a patient does not exclude the diagnosis of a familial aortopathy.
In an unaffected person from a family with confirmed genetic diagnosis of familial aortopathy, the presence of the family’s mutation may indicate an increased risk of developing thoracic aortic disease, 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 required.
This test involves analysis of a number genes. Details of this gene panel and potential incidental findings are summarized here.
Analysis of a gene panel for sequence abnormalities and deletions/duplications.
This test is provided by Bioscientia, a Sonic Healthcare laboratory in Germany. Bioscientia is accredited within Germany and by the College of American Pathology for the provision of medical genetic tests.
This test is usually requested by a cardiologist with experience in the genetic management of cardiac disease or a clinical geneticist.
2-5 mL blood in EDTA. Specimens may be collected by the requesting practitioner or at any Sonic Healthcare pathology collection centre.
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 also 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.