The aorta is the major blood vessel leaving the heart that carries blood to the rest of the body. Thoracic aortic aneurysm and/or dissection (TAAD) is characterized by widening (dilation) of the aorta which may cause a bulge (aneurysm) or lead to a tear (dissection). TAAD can occur in an isolated individual or run in families, called familial TAAD.
While aortic aneurysms are common worldwide, the exact number of people with familial TAAD is unknown.
Aortic aneurysms usually cause no symptoms unless they result in a tear or rupture. Severe, abrupt chest pain is the most common sign of an aortic tear or rupture, which can be life-threatening. The age of onset of TAAD is highly variable from family to family and among individuals in the same family. However, those with familial TAAD tend to develop aneurysms at an earlier age and have a quicker progression than non-familial TAAD. The aorta is the structure most affected by familial TAAD, but other cardiovascular features may also be present.
TAAD can be one feature of a syndromic condition involving multiple other body systems. The most common of these conditions are Marfan syndrome, Loeys-Dietz syndrome (LDS), and vascular Ehlers-Danlos syndrome (vEDS).
Familial TAAD is diagnosed clinically by the presentation of aortic aneurysm, dilation, and/or dissection in an individual with a family history of the same when syndromic causes of aortic disease have been ruled out (Marfan, LDS, and EDS).
There are several genes associated with causing familial TAAD.
Genetic testing can help distinguish familial TAAD from other syndromic causes of aortic disease (Marfan, LDS, and EDS). Once a genetic diagnosis is established in an individual, genetic testing can be used to clarify which other family members are at increased risk for TAAD and which are not. This can be very important because family members at risk for TAAD may have no symptoms at all.A negative genetic test result in an individual with TAAD does not mean the individual does not have TAAD. It simply means we have not yet identified what caused TAAD for this individual. Not all individuals with TAAD will have a positive genetic test result.
Management of individuals with TAAD is recommended to be coordinated through a multidisciplinary team including medical geneticist, cardiologist, and cardiothoracic surgeon. Treatment recommendations are based on the amount and progression of aortic dilation and may include medication and/or surgery. Additional evaluations may be appropriate based on the individual’s history, family history, or specific gene associated with the diagnosis.
Genetic testing can help identify individuals with familial TAAD and guide medical recommendations. Genetic test results may guide surgeons on when and how to repair an aortic aneurysm or whether or not to perform evaluations outside of aortic screening.
If the genetic cause of TAAD is identified in an individual, genetic testing for other family members may be indicated to assess their risk for TAAD and the need for possibly life-saving treatment. Family testing is important because relatives may be at risk regardless of whether or not they are experiencing any symptoms.
Your physician will assist you in identifying and arranging for the appropriate genetic test(s). If you have specific questions or concerns about the testing, your physician may refer you to a genetic counselor to discuss further. Once you are ready to proceed with genetic testing, you will need to submit either a blood or saliva sample.