Multiple loci have been identified, including the TAAD1 locus mapped to 5q13-14, the FAA1 locus mapped to 11q23.3-24, the TAAD2 locus mapped to 3p24-25 with TGFBR2 being the mutant gene, the TAAD3 locus mapped to 15q24-26, and the TAAD4 locus mapped to 10q23-24 with ACTA2 being the mutant gene [6].