Center for Human Genetics and Laboratory Diagnostics, Dr. Klein, Dr. Rost and Colleagues

Aortic aneurysm, familial thoracic 6 (AAT6) [I71.1] [I71.2]

OMIM numbers: 611788, 102620 (ACTA2)

Dr. rer. nat. Karin Mayer

Scientific Background

In 2007 the gene locus AAT6 for TAAD was mapped on chromosome 10q22–24 and mutations in the ACTA2 gene were identified. ACTA2 encodes alpha actin of the vascular smooth muscle. Mutations can be detected in about 10–14% of patients diagnosed with TAAD and therefore constitute the most frequent genetic cause of TAAD. Some patients carrying ACTA2 mutations show additional symptoms like livedo reticularis, iris flocculi and a patent ductus arteriosus. The penetrance of the development of thoracic aneurysms and dissections in heterozygous carriers in the family of an index patient with an ACTA2 mutation is 50%. Heterozygous ACTA2 mutations are associated with different vascular diseases like coronary heart disease, ischemic stroke, and cerebrovascular moyamoya disease.