OBJECTIVES: The association between bicuspid aortic valves and aortic aneurysms has been well documented. In order to better understand this association, this study sought to accomplish two goals. The first was to determine if there was any correlation between specific bicuspid aortic valve phenotypes and aortic aneurysms. The second goal was to determine if the association between bicuspid aortic valve disease and aortic aneurysms has a genetic or hemodynamic cause. METHODS: For the non-genetic portion of the study, we used echocardiogram and surgical records to classify the phenotypes of the aortic valve and the aorta of 434 patients. We then evaluated the correlation between valve morphotype and aortic aneurysm phenotype. For the genetic portion, we used a genome wide association study on 452 patients to find genes that could potentially be responsible for aortic aneurysms. These were then compared with genes suspected of causing bicuspid aortic valve to determine if there is a common genetic link between the two disorders. RESULTS: We observed a significant association between bicuspid aortic valve and aortic aneurysms; however we did not find any significant association between the different bicuspid aortic valve phenotypes and aortic aneurysm phenotypes. For the genome wide association study, we identified genes that could potentially be responsible for causing aortic aneurysms; however, none of the suspected markers were considered statistically significant. Also none of the identified genes matched to the genes suspected of causing bicuspid aortic valve. CONCLUSION: While the results were not as expected, the study provided us with information to better understand the relationship between bicuspid aortic valves and aortic aneurysms. According to the results of the current study, patients with bicuspid aortic valve are more likely to develop an aortic aneurysm but specific phenotype has no effect on where the aneurysm occurs in the aorta. The increased frequency of aortic aneurysms in bicuspid valve patients is most probably due to a combination of altered hemodynamics and genetic effects. In order for this information to be useful in the clinical setting, the methods of this study should be repeated in a larger cohort to make sure the results are accurate.