I was diagnosed on an echocardiogram with mild mitral regurgitation. in absence of any other cardiac findings and comorbidities. i'm athletic and non smoker, what could be the reasons for my condition?

If the conclusion is only a trace of mitral regurgitation & everything else.is perfectly normal and you have no heart murmur, I would disregard this. It's stated that up to 30% of echocardiograph diagnoses may be inaccurate to some degree. Trivial mitral regurgitation is often described in many healthy people's echocardiograms. If you still have concerns, consult a cardiologist for evaluation & ad