That is bit like saying that the mains supply causes your computer to crash. Mitochondria are the powerhouses of everything - the mains supply. So if they are not working you get something called death.
Not really. There are a lot of ways that mitochondria can dysfunction, resulting in different severity.
Even if we just look at genetic causes, mitochondrial mutations can result in death shortly after birth, or good health well into adulthood. And in later-onset cases, death is less likely and takes a lot longer. There are different mitochondrial genes which affect different stages of the electron-transport chain, with some problems at some stages being more severe than mutations at other stages. And within each stage, there are different genes where mutations will have a different impact. And within those genes, different mutations will be more or less severe than others.
Mitochondrial mutations can also be heteroplasmic, meaning only certain tissues will be affected, and those tissues vary from case to case. Obviously some of those will be more deadly than others. Eg, MELAS is bad news because malfunctioning mitochondria in the muscles result in elevated lactate in the CNS which can trigger strokes and seizures. Whereas MIDD results in diabetes and deafness, and while that obviously sucks, it isn't deadly.
Then there are nuclear DNA mutations which are also involved in mitochondrial function. While some mutations would be deadly before or soon after birth, other mutations are known to only start causing problems when under physiological stress, such as hypoxia or infection.
And then there can be non-genetic factors. I'm not particularly clear on what these might be, but mitochondrial specialists seem to be quite sure that they exist.
And we do not yet have any real evidence there is anything wrong with the mitochondria in ME.
I'm less confident of that. There are a lot of patients on the forum with a maternal history of similar symptoms, and many are mothers with similarly sick children. And there are more than I'd expect with a history of extra non-ME symptoms suggestive of mitochondrial disease, such as hemiplegia, seizures, progressive eye problems, progressive hearing problems, trouble swallowing, diabetes, thyroid dysfunction, etc.
I certainly don't think mitochondrial disease is the same thing as ME. But I suspect that many classic mitochondrial disease patients are misdiagnosed with ME. And I'd be quite surprised if there wasn't mitochondrial dysfunction involved in most other patients with PEM.
Also, SNPs known or suspected of causing mitochondrial disease were about 10x more common in ME patients than the general public in a recent study from South Africa and England. And that was with using a testing method which made it extremely unlikely that any heteroplasmic mutations would be detected. Unfortunately the researchers were either very incompetent or determined to get a negative result, so didn't mention the evidence regarding most of those mutations, and retested positive patients with the undeniably pathogenic mutations to make sure they disappeared the 2nd time around.
