PRKG1 and familial thoracic aortic aneurysm and aortic dissection: Nonsyndromic aortopathy is increasingly recognized as an important clinical entity, seen in up to 89% of aortopathy cohorts.47 The underlying genetic causes of nsHTAD include mutations in genes encoding members of TGFβ signaling pathway (TGFBR1, TGFBR2, TGFB2, SMAD3); the structure and integrity of the aortic wall extracellular matrix, including FBN1 (described earlier); COL3A1 and lysyl oxidase (LOX); or those affecting the function of smooth muscle cells, including actin (ACTA2), myosin (MYH11), myosin light chain kinase (MYLK), and protein kinase cGMP-dependent 1 (PRKG1).