Familial aortic dissection

Familial aortic dissection (also known as familial thoracic aortic aneurysm and dissection, or FTAAD) is a heritable condition in which the wall of the aorta — the body's largest artery — is prone to tearing (dissection) and/or abnormal widening (aneurysm). In aortic dissection, blood forces its way between the layers of the aortic wall, creating a false channel that can rapidly become life-threatening if the aorta ruptures. The condition primarily affects the cardiovascular system, with the thoracic (chest) portion of the aorta most commonly involved, though the abdominal aorta may also be affected. Key symptoms can include sudden, severe chest or back pain described as tearing or ripping, and in some cases the dissection may be preceded by a clinically silent progressive enlargement of the aorta (aortic root or ascending aortic dilation). Familial aortic dissection is genetically heterogeneous, meaning mutations in several different genes can cause the condition. Known causative genes include ACTA2 (the most commonly implicated, accounting for roughly 10-15% of familial cases), TGFBR1, TGFBR2, MYH11, SMAD3, MYLK, LOX, PRKG1, and others involved in smooth muscle cell contractility or TGF-beta signaling. The condition follows an autosomal dominant inheritance pattern with variable expressivity and incomplete penetrance, meaning that not all individuals carrying a pathogenic variant will develop dissection, and the age of onset and severity can differ even within the same family. Importantly, familial aortic dissection can occur in the absence of syndromic features seen in related connective tissue disorders such as Marfan syndrome, Loeys-Dietz syndrome, or vascular Ehlers-Danlos syndrome. Management centers on regular cardiovascular surveillance with echocardiography, CT angiography, or MRI to monitor aortic dimensions. Medical therapy typically includes beta-blockers or angiotensin receptor blockers to reduce hemodynamic stress on the aortic wall and slow the rate of aortic dilation. Prophylactic surgical repair of the aorta is recommended when the aortic diameter reaches a threshold (often 4.5–5.0 cm, though gene-specific thresholds may be lower, particularly for TGFBR1/TGFBR2 mutations). Emergency surgery is required for acute dissection. Genetic testing and cascade screening of at-risk family members are strongly recommended to identify individuals who may benefit from surveillance and preventive treatment before a potentially fatal event occurs.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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