I am adding a new part to my hypothesis about these mitochondrial dysfunction illnesses. It will undoubtedly change as I learn more, and maybe it will get dropped, but I thought it might be interesting for some of the people here. A few weeks ago I thought that PEM was caused by a person using the pathway to take 2 ADP and make 1 ATP and 1 AMP, as per Sarah Myhill's hypothesis. But now I have changed my mind because of all the posting here about how baking soda helps lessen PEM. In these mitochondrial dysfunction illnesses alternative pathways to ATP production must be used, because the electron transport chain (ETC) is inhibited and the person is not making enough ATP through oxidative phosphorylation (the TCA cycle and ETC). The only alternative energy pathways that I know about so far are gylcolysis and the folate cycle. I think that people with ME/CFS use the glycolysis pathway heavily, and it is the delayed effects of the buildup of lactic acid that causes PEM. I hypothesize that the ability to use the glycolysis pathway as an althernative energy source may be greater in women than in men because it can help women in childbirth. So, many men are not able to use the glycolysis pathway enough to cause PEM. The folate pathway is next in line after glycolysis as a backup for energy and the majority of men start right off with the folate pathway as the alternative energy source when they have mitochondrial dysfunction (if they have enough folate, otherwise they are tired all the time). This would also explain why although men and women get schizophrenia at the same rate, men get it a couple of years earlier than women do on the average. Women start out using the glycolysis pathway more than men, but as the mitochondrial failure gets worse they are forced to start using the folate pathway, too, and that's when susceptible women start having the symptoms of schizophrenia, because schizophrenia symptoms are caused by using the folate pathway, and not the glycolysis pathway. In order to get PEM or schizophrenia from these pathways, you have to have the genetic susceptibility for those symptoms.