I have been sick for at least 13 years, with some symptoms going back into my childhood. At first I was told I had Post Viral Fatigue Syndrome, then later Myalgic Encephalomyelitis. (ME.) ME is also referred to as Chronic Fatigue Syndrome, (CFS) although this is controversial as chronic fatigue is often a symptom of other illness. ME/CFS is a diagnosis of exclusion. That is, there is no known cause or definitive test for it and when every other possibility is excluded the symptoms get labelled as ME. I have often wished that I had any other disease – something with a known cause, where it is not so easy for people to label you a fake or a lazy scrounger. This wish got even more intense when I went to see a psychiatrist after becoming suicidal with pain. His response was to ignore my depression and suicidal ideation and instead “diagnose” me with Chronic Fatigue Syndrome, which from his point of view is a mental illness, and prescribe exercise as the cure to all my problems.
Then four years ago I became diabetic too. It wasn’t unexpected given my family history and I adapted to it pretty easily, although I resented having to change what I eat. Since I was diagnosed my diabetes has progressed rapidly and a few weeks ago I went to see a specialist because despite insulin treatment I was responding unpredictably and finding it hard to control my blood glucose. He suspected that I had a form of diabetes called MODY and had some blood samples taken for a genetic test.
On Friday I got the results of that test back and everything changed.
I don’t have MODY, I have Maternally Inherited Diabetes and Deafness. (MIDD.) It’s caused by a mutation in mitochondrial DNA (3243 tRNA), specifically 3243A>G.
Apart from diabetes and deafness (The deafness part is only about 75% of cases) MIDD is associated with some other symptoms. From the information sheet at the Diabetes Genes website:
Myopathy (Muscle weakness): muscle problems of either weakness or cramps may be present in around 40% of cases of MIDD. This generally involves proximal muscles (shoulders, buttocks and thighs) which are used when climbing stairs and presents as exercise induced muscle cramps or weakness.
Metformin, a commonly used treatment in diabetes is probably best avoided as Metformin is known to interfere with mitochondrial function and the risk of lactic acidosis may be increased although this has not been reported to date.
I’ve been feeling so, so tired recently with aching legs, and I can barely get out of bed and get dressed some days, most of the time I just want to lie on the sofa and sleep. I knew MIDD could make you tired after exercise, but I didn’t realise it could make you so fatigued after not doing anything at all!
Turning to The NHS Rare Mitochondrial Disease Service for more information I found this under General Information > Exercise
Because in mitochondrial disease the cells cannot make ATP in sufficient quantity, anything that requires a lot of ATP such as exercising a muscle will mean that the body will not be able to keep up with demand. This has two main effects; firstly the muscle will become tired sooner than normal and secondly the muscle makes other compounds such as lactic acid in an attempt to keep up with energy demand. This can lead to pain and cramp in the muscles and patients often feel “like they have run a marathon” even after only moderate exercise. The temptation is to avoid all exercise so that you never get to this stage, but this is not recommended for two reasons. Firstly, it is important for general fitness to exercise and as well as exercising the muscles it is important to keep the heart and circulation healthy. Secondly, there is good evidence that if you become very unfit this will adversely affect your muscles. In many patients’ muscles there is a mixture of good and bad mitochondria and the hope is that exercise can increase the good mitochondria, boosting the level of ATP back to normal and so avoiding symptoms. At this stage this remains just a theory and there are large trials looking in to this idea. At the present time our advice is to exercise regularly at a level that feels comfortable, but without pushing yourself to the point that your muscles become painful.
But that’s not all. The Rare Mitochondrial Disease Service has another perspective on the 3243A>G mutation. It is responsible for a condition called Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes (MELAS). And it’s scaring the shit out of me.
The clinical features associated with this mutation can, as stated above, be very variable. We have a number of individuals who clearly carry the mutation who are completely asymptomatic. Other patients have very, very mild symptoms perhaps with a tendency to have diabetes or very mild deafness requiring no treatment. These patients might not be aware that they had the mutation apart from the fact that they were family members of somebody who had more serious disease. Some people with the 3243A>G mutation, also develop diabetes and deafness ultimately requiring the use of a hearing aid or requiring insulin to control their diabetes. Other patients have more severe involvement with muscle weakness sometimes affecting the peripheral muscles and sometimes affecting the muscles around the eyes. Finally there is a group of patients who do develop the MELAS syndrome, which is associated with episodes of encephalopathy . Encephalopathy is really the medical term for an episode that disturbs brain function. These disturbances can take the form of stroke- like episodes and/or seizures. This is a much more troublesome and difficult group of symptoms to control and clearly have a significant effect on people’s lifestyle.