Yesterday I had my appointment with an internist from the mitochondrial disease clinic. It went very well - he's investigating things seriously.
He's running some blood and urine tests which look for certain alterations regarding amino acids, fatty acids, and some other things which can occur with mitochondrial disease. These are a bit hit-and-miss in being abnormal in mitochondrial disease patients, but if it's a "hit" then it can indicate a diagnosis without doing the more aggressive testing.
Mitochondrial DNA is also being sequenced from my urine sample. This can miss mutated mitochondrial DNA, but rarely does when the mutants are wide-spread and symptoms are pronounced. It has about a 4-5% false-negative rate, so again can be a painless way to confirm a genetic mitochondrial disease, even if it can't fully rule one out. It's much more accurate than blood, when looking for heteroplasmic mutations.
Blood lactate was also tested, which can also be a bit of a hit-and-miss. It's often normal in patients with mitochondrial disease much of the time, but is more likely to be abnormal following exertion. So the internist had a sample taken, then I walked up and down a huge flight of stairs, then another sample. I'm not sure what that will turn up, since I haven't had any large elevations from home testing after moderate exertion, just random elevations at bed time, and weird ongoing bursts after a 4 minute step test I did. I measured at bed time again last night, and it was elevated, so there's a good chance my lab values will have been high as well.
The impression I got is that this isn't the end of testing unless it comes up positive for a mutation or other strong indication in my blood or urine. If it is negative, more aggressive testing can be done. The internist did seem to think that mitochondrial dysfunction was a definitely possibility, though the cause and diagnosis couldn't be determined. It might be from the mitochondrial DNA, or other DNA involving mitochondrial reactions, or other diseases which result in reduced mitochondrial activity as a downstream effect. So perhaps he'd be interested in looking into those more even if my mitochondrial DNA is normal.
The DNA testing takes 6-7 weeks, so my next appointment is in 8 weeks. The hospital has secure online access for patients, so I can see most of my results there. Though I need to call a week before the appointment, to make sure results are in and we don't wast a long drive, since the DNA results won't be on there. Not surprising, since DNA files can get pretty huge. Mitochondrial DNA is very short compared to chromosomal DNA, but since it's testing for heteroplasmic mutations, it might contain dozens of readings of it. Anyhow, it'd be hard for them to store or upload a lot of that data electronically.
So it was a very good appointment, even if not exactly the outcome I wanted, which would be more aggressive testing immediately. It involved 3 hours at the hospital though, with an hour for registration, talking to nurses, height and weight checked, etc, then an hour in the actual appointment, and another hour for peeing, EKG, blood draws, and stairs. And about 3 hours of driving total, so it was a long and really exhausting day. My heart rate was already high when we got there, and by the time we got home it was 100-110 while lying on the couch. So I'm pretty wiped out currently, and expecting a full crash in a few hours.
He's running some blood and urine tests which look for certain alterations regarding amino acids, fatty acids, and some other things which can occur with mitochondrial disease. These are a bit hit-and-miss in being abnormal in mitochondrial disease patients, but if it's a "hit" then it can indicate a diagnosis without doing the more aggressive testing.
Mitochondrial DNA is also being sequenced from my urine sample. This can miss mutated mitochondrial DNA, but rarely does when the mutants are wide-spread and symptoms are pronounced. It has about a 4-5% false-negative rate, so again can be a painless way to confirm a genetic mitochondrial disease, even if it can't fully rule one out. It's much more accurate than blood, when looking for heteroplasmic mutations.
Blood lactate was also tested, which can also be a bit of a hit-and-miss. It's often normal in patients with mitochondrial disease much of the time, but is more likely to be abnormal following exertion. So the internist had a sample taken, then I walked up and down a huge flight of stairs, then another sample. I'm not sure what that will turn up, since I haven't had any large elevations from home testing after moderate exertion, just random elevations at bed time, and weird ongoing bursts after a 4 minute step test I did. I measured at bed time again last night, and it was elevated, so there's a good chance my lab values will have been high as well.
The impression I got is that this isn't the end of testing unless it comes up positive for a mutation or other strong indication in my blood or urine. If it is negative, more aggressive testing can be done. The internist did seem to think that mitochondrial dysfunction was a definitely possibility, though the cause and diagnosis couldn't be determined. It might be from the mitochondrial DNA, or other DNA involving mitochondrial reactions, or other diseases which result in reduced mitochondrial activity as a downstream effect. So perhaps he'd be interested in looking into those more even if my mitochondrial DNA is normal.
The DNA testing takes 6-7 weeks, so my next appointment is in 8 weeks. The hospital has secure online access for patients, so I can see most of my results there. Though I need to call a week before the appointment, to make sure results are in and we don't wast a long drive, since the DNA results won't be on there. Not surprising, since DNA files can get pretty huge. Mitochondrial DNA is very short compared to chromosomal DNA, but since it's testing for heteroplasmic mutations, it might contain dozens of readings of it. Anyhow, it'd be hard for them to store or upload a lot of that data electronically.
So it was a very good appointment, even if not exactly the outcome I wanted, which would be more aggressive testing immediately. It involved 3 hours at the hospital though, with an hour for registration, talking to nurses, height and weight checked, etc, then an hour in the actual appointment, and another hour for peeing, EKG, blood draws, and stairs. And about 3 hours of driving total, so it was a long and really exhausting day. My heart rate was already high when we got there, and by the time we got home it was 100-110 while lying on the couch. So I'm pretty wiped out currently, and expecting a full crash in a few hours.
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