Newly mapped gene for thoracic aortic aneurysm and dissection.

Thoracic aortic aneurysm and dissection (TAAD) is associated with high mortality and medical expense. These poor outcomes are preventable by surgical repair; however, identifying at-risk individuals is difficult. Researchers are actively surveying the human genome (the repository of human genes) to characterize the genetic determinants of TAAD by identifying chromosomal regions likely to harbor such predisposing genes. In previous studies, investigators identified genetic markers shared by a subset of families who were ascertained to have the disease, which clustered into 2 chromosomal regions: 5q13-q15 (TAAD1) and 11q23.2-q24 (familial aortic aneurysm [FAA1]). In a subsequent study, a third chromosomal region at 3p24-25 (TAAD2) was found to contribute to TAAD in a 4-generation, 52-member family that displayed little evidence of sharing either the TAAD1 or FAA1 regions. Although additional regions of the genome may contribute to TAAD, investigators are focusing their efforts on identifying the actual genes and the specific mutations that participate in the disease process. The goal of these endeavors is to develop screening tests to identify individuals at risk for familial TAAD. This genetic discovery has significant clinical implications because high-risk individuals and families can be closely monitored and can benefit from preventative surgical repairs.