Bicuspid aortic valve (BAV) is considered the most common congenital heart disease, affecting around 0.8% of the population. It can lead to serious complications like valve dysfunction or aortic dilatation, often requiring surgery. BAV is heritable, but the underlying causes and risk factors are not fully understood. Current guidelines recommend screening in families with multiple affected members, but the benefits of screening all families with BAV are unclear. This clinical project aims to build a large cohort of patients with BAV, by screening first-degree relatives to newborns with BAV and younger patients who underwent surgery for BAV disease. The project will examine clinical and genetic factors to improve screening, risk assessment, and long-term care. By comprehensive and systematic examination of a large cohort of BAV patients and their families, the project hopes to provide new insights into how the disease develops, improve early detection, and inform future management.