We suppose the underlying issue here is whether the mitral valve prolapse is actually connected to the symptoms which your son is experiencing. The ones which you report are not the standard problems noted in these cases, and if this is a separate and unrelated problem then it substantially changes the advice we can offer.
As far as the treatment of MVP itself is concerned there is no evidence that we can find that acupuncture treatment has been documented in helping to reduce the symptoms associated with MVP. There are several complementary medicine articles which point to the use of magnesium, which has been linked to the muscle weakness, but nothing which mentions treatment by acupuncture. Whether magnesium is effective as a supplement is beyond our scope for comment.
If, however, the symptoms are of a different problem related to a weakened immune system, i.e. not directly resulting from the MVP, then there may be some reason for cautious optimism. There have been a number of studies which have shown effective increases in immune response and immune system body chemistry as a consequence of treatment, and a greater number of studies of of successful treatment of some of the emotional disorders associated with a weakened immune response, anxiety being one of the primary ones. The research is far from conclusive, but suggestive of the fact that there may be a chance that change will happen.
The bottom line with complex presentations is that it really needs someone to take a look at the individual to see how the symptoms present against the backdrop of all aspects of the person's health. Not only does the traditional acupuncturist treat the individual rather than simply treat the condition, but the health of the individual can seriously affect the speed with which something can clear up, or indeed whether it can clear up. The best advice is to see a local practitioner for this kind of informal assessment before committing to treatment.
The one caution about treating anyone with MVP is that there is thought to be a known increase in risk of endocarditis if the skin is not cleaned before needles of any kind are inserted, and there is an absolute embargo on the use of any form of retained needle. This is occasionally disputed, as in this paper
but we always advise our members to treat people with heart valve problems as though they were immuno-compromised