Aortic aneurysm, familial thoracic 4 (AAT4) [I71.1] [I71.2]
Dr. rer. nat. Karin Mayer
In 2005 the gene locus AAT4 for TAAD was mapped on chromosome 16p13.13–p13.12. In 2006 mutations in the MYH11 gene were identified by a mutational analysis within the candidate region. MYH11 codes for the heavy chain of myosin-11 in the vascular smooth muscles. MYH11 mutations were identified in about 1% of families with TAAD. So far, all affected carriers have also had a patent ductus arteriosus. Mutations in MYH11 are associated with medial thickening of the arteries in the vasa vasorum. Deletions and missense mutations in the C-terminal domain of MYH11 seem to impair the structure and aggregation of myosin filaments which are mainly responsible for contraction.