I . I am not exactly sure what your question is but would be happy to help if you could provide more information. You are likely referring to congenital aortic stenosis which is caused by abnormal formation of the valve leaflets of the aortic valve which is the last valve that blood passes through as it leaves the heart. A normal valve has 3 leaflets (tricuspid) but abnormal valves with only 2 leaflets (bicuspid, affecting up to 1% of the population) or 1 leaflet (unicuspid) are recognized.
More Info. Please provide some more information. There is no question here and we would like to help.