Thoracic aortic aneurysms leading to type A dissections (TAAD) can be inherited in isolation or in association with genetic syndromes, such as Marfan syndrome and Loeys-Dietz syndrome. When TAAD occurs in the absence of syndromic features, it is inherited in an autosomal dominant manner with decreased penetrance and variable expression, the disease is referred to as familial TAAD. Familial TAAD exhibits significant clinical and genetic heterogeneity. The first genes identified to cause TAAD were FBN1, TGFBR2, and TGFBR1. The identification and characterization of these genes suggested that increased TGF-beta signaling plays a role in pathogenesis. The recent discovery that mutations in the vascular smooth muscle cell (SMC)-specific beta-myosin (MYH11) and alpha-actin (ACTA2) can also cause this disorder has focused attention on the importance of the maintenance of SMC contractile function in preserving aortic structure and preventing TAAD.

中文翻译：

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胸主动脉瘤和夹层的遗传基础：侧重于平滑肌细胞收缩功能障碍。

导致A型夹层（TAAD）的胸主动脉瘤可以单独遗传，也可以与遗传综合症（如马凡氏综合症和Loeys-Dietz综合症）结合使用。当TAAD在没有症状特征的情况下发生时，以常染色体显性方式遗传，其外显率和表达降低，该疾病称为家族性TAAD。家族性TAAD表现出明显的临床和遗传异质性。被鉴定为引起TAAD的第一个基因是FBN1，TGFBR2和TGFBR1。这些基因的鉴定和表征表明增加的TGF-β信号传导在发病机理中起作用。