PAA may share TAAD predisposing genes mutations interesting the transforming growth factor beta (TGFβ) signal, extracellular matrix (FBN1, TGFBR1, TGFBR2, SMAD3, TGFB2, COL3A1), and altered components of the contractile apparatus of the smooth muscle cells (SMC): ACTA2, MYH11, MYLK, and PRKG1 [4,29]. The gene discussed is COL3A1; the disease is pulmonary artery-aorta diameter ratio measurement.