My little brother was diagnosed at 6, they kept missing it (this was in 1988). He never really outgrew it, but my parents took him to a pediatric cardiologist, who kept a tight watch on him and he is now 25 yrs old, graduate college, where he played on the golf team. He was also in the starting lineup for his varsity football team for 3 yrs in high school. As long as you keep a watch on it and get a good pediatric cardiologist, it won't be a problem. If it gets worse or anything, they'll catch it and you may have some ups and downs but hopefully not. The most important thing is to work well with the dr. and a pediatric cardiologist is the key, not one that also sees adults, you want someone who sees kids all day long and specializing in that. Good luck!!