In this condition, instead of three valve cusps, the aortic valve has two cusps which results from the fusing of one of the commissures.<unk>  aortic stenosis is the most common congenital abnormality of the heart accounting for 5% of congenital heart defects and it occurs in 1-2% of the population.  It can be manifested as a murmur and usually has no long term health consequences, but if it does, the manifestation of aortic stenosis occurs 10 years earlier.
Bicuspid aortic stenosis epidemiology and demographics
Tricuspid stenosis epidemiology and demographics
Aortic regurgitation epidemiology and demographics
Mitral stenosis epidemiology and demographics
Aortic stenosis epidemiology and demographics
Tricuspid regurgitation epidemiology and demographics
Mitral stenosis anatomy and pathophysiology
Mitral regurgitation epidemiology and demographics