A quick Google search of “adult-onset McArdle’s disease” will yield volumes of medical abstracts on patient studies. I’ve seen plenty of other abstracts that point out that the disease is not often diagnosed until at least the second or third decade of life. Perhaps this is because this is around the time the body’s metabolism starts to slow down a little, and the “weekend warrior” injuries become more common (and considerably more complicated, without glycogen in the picture.)
There may in fact be an adult-onset form of McArdle’s disease. I also suspect that many newly-diagnosed adults have lived with the disease their entire lives and simply gone without diagnosis, “toughing it out”. (In another article, I talk about how children with McArdle’s disease in particular are particularly vulnerable.)
A concerted campaign to educate grade school gym teachers, pediatricians and health care professionals about McArdle’s disease could spare many people the punishment of trying to force their bodies to do things they simply weren’t equipped to do. This may enable them to participate in alternate activities tailored to their unique condition, and improve their health later in life as a result through earlier proactive management of the disease.
Ultimately the question of whether or not there is an adult-onset form of McArdle’s is probably not as important as is education and information. The more people know about McArdle’s disease, the less likely it is that children and adults who remain undiagnosed will suffer and live with unanswered questions. Your feedback on this topic is welcome.