Although he had no family history of cardiovascular diseases, including aortic dissection, or aortic aneurysm, connective tissue disease was suspected due to his own history of aortic root dilatation and recurrent aortic dissection; thus, a genetic test was conducted (tested genes: FBN1, FBN2, TGFBR1, TGFBR2, TGFB2, TGFB3, SMAD2, SMAD3, ACTA2, COL3A1, EFEMP2, FLNA, MYH11, MYLK, SLC2A10). The gene discussed is COL3A1; the disease is Aortic dissection.