The following is an interview with Dr. Boles:
Why is mitochondrial disease so tough to diagnose?
Dr. Richard G. Boles: Mitochondrial disease affects many different levels. All the cells in the body require energy. If there's not enough energy, any number of cells can fail.
Mitochondrial disease can cause problems to any part of the body. Because mitochondrial disease can show up as many different things and because there's not one perfect test for mitochondrial disease, diagnosis becomes very difficult.
What are the advantages to catching the disease when the patient is very young?
Dr. Boles: Some patients with mitochondrial disease do progress and get worse over time; others have more stable courses. What's most common is an intermittent course in which the disease will come and go. With treatment, most patients do improve to some degree – some dramatically.
What are some of the treatments that you use for it?
Dr. Boles: Many of the treatments have to do with diet – frequent feedings, lower fat meals, and sometimes patients need to eat throughout the night – exercise, which increases mitochondrial number but needs to be done in moderation, and then certain vitamins and other co-factors which increase mitochondrial function, such as B vitamins,
riboflavin, co-enzyme Q10, and others.
How does this new test work?
Dr. Boles: What this test does is it looks at the mitochondrial DNA and sequences, or determines the genetic code, at each of the over 16,000 base codes within. Not only does it do that, but it looks for small abnormalities that indicate a new mutation: the genetic change that causes the disease.
Catching the disease early with this test, what would that mean for someone like Gwynnie?
Dr. Boles: She already has a diagnosis, so for her, it could mean more a precise diagnosis that might be used for family planning purposes, for the testing of other family members that do not have any symptoms now but may or may not develop symptoms in the future. The true promise for this test is for children that do not have diagnosis of
mitochondrial disease for which this test might identify this as being present.
How big of a breakthrough is this to have a test like this?
Dr. Boles: There are a few other labs in the world that recently started mitochondrial sequencing, and that's what this test does as well; but what those tests do not do is look for heteroplasmy, which is the presence of two different genetic codes, so you get a lot
of data. With this test, you can take a look at that, and find out which one of the many genetic changes which make us all different is the one which causes the disease.
Do you think the test will ever be able to be used for other diseases in the future?
Dr. Boles: Mitochondria are involved with a large number of processes; a large number of people with migraines, autism, diabetes, seizing disorders, mental retardation, and many other conditions actually have mitochondrial abnormalities causing the disease.
If you would like more information, please contact:
Steve Sommer, MD, PhD, FACMG