Acute Aortic Disease.. - Index of

INTRODUCTION
6
Genetic Basis of Thoracic
Aortic Aneurysms
and Dissections
Dianna M. Milewicz, Hariyadarshi Pannu,
Nili Avidan, Dong-chuan Guo,
and Van Tran-Fadulu
Division of Medical Genetics, Department of
Internal Medicine, University of Texas Medical School,
Houston, Texas, U.S.A.
The natural of aneurysms involving the ascending aorta is to progressively enlarge
over time, leading to an ascending aortic dissection in the absence of prophylactic
repair of the diseased segment of the aorta. Therefore, thoracic aortic aneurysms
and ascending aortic dissections are related conditions, termed thoracic aortic
aneurysms and dissections (TAAD) for this chapter. It is well established that
known genetic syndromes predispose to TAAD, such as Marfan syndrome (MFS).
This chapter will review genetic syndromes that are associated with TAAD,
including MFS and Loeys-Dietz aortic syndrome (LDAS).
The majority of patients with TAAD do not have a named genetic syndrome.
Up to 20% of patients referred for surgical repair have a family history of TAAD,
suggesting a significant genetic component to this disease. Families characterized
with multiple affected members have demonstrated that the condition is typically
inherited in an autosomal dominant manner with decreased penetrance and variable
expression. This chapter will also review the mapping and identification of
genes causing nonsyndromic, familial forms of TAAD.
99