Linda's Friedreich's Ataxia
Many of you know of Linda's disease. If you don't, you may have noticed something about her walk; and her speech may seem a little slurred. Has she been drinking? If it was only that simple... she has Friedreich's Ataxia. It's a genetic disorder that's gradually taking away her mobility. The nerves that connect her muscles with her brain are deteriorating. And since it's a progressive deterioration, her condition will only get worse. Most people with Friedreich's Ataxia don't even know it until they first notice the symptoms, and then ten or fifteen years later they are confined to a wheelchair.
When Linda was in her late thirties she started noticing problems with her balance and speech. The problems got progressively worse, where walking took actual concentration instead of being an unconscious activity. In April of 2002 genetic testing determined that she has Friedreich's Ataxia (FA). At this point Linda can get around fine for the most part, although she has some problems. The symptoms typically are as if she has been drinking - kind of a stumbly walk and occasionally a slightly slurred speech. In general, she has to watch her feet to walk. Stairs, in particular, are difficult - especially going down. Any walking on uneven ground or in the dark is difficult. She needs to hold on to someone when walking on anything slippery, uneven, or that she can't see. Her speech and writing are affected, but only slightly. She shows none of the more serious problems that are sometimes associated with ataxia (heart trouble, diabetes, vision problems, etc.). She can no longer run, ski, ride a two-wheeled bike, dance, or wear high heels.
The disease doesn't get much attention; only around 6,000 people have it in the United States. That might sound like a lot, but compare that with over 1 million with Parkinson's; 300,000 with MS; 30,000 with ALS (Lou Gehrig's disease). Not to mention cancer and AIDS. Maybe this common definition will help:
Orphan disease: A disease which has not been "adopted" by the pharmaceutical industry because it provides little financial incentive for the private sector to make and market new medications to treat or prevent it. According to US criteria, an orphan disease is one that affects fewer than 200,000 people, or one that has been ignored because it is far more prevalent in developing countries than in the developed world.
This disease would not seem overly complicated. There is a protein in our bodies called frataxin that regulates the buildup of iron inside mitochondria. In someone with Friedreich's Ataxia, the frataxin protein is defective, and as a result iron builds up in the mitochondria, which causes damage. That's about it. If we could just fix the frataxin, or keep the iron from building up, maybe we could solve the problem. Medicine is making amazing progress at this time in our history. In fact it was less than ten years ago that the gene responsible for this disease was isolated.
Plenty more information is provided below, along with links to some great sites on the subject. Or Return to Our Blog.
What is Friedreich's Ataxia?
FA is a condition that slowly degenerates the nerves carrying signals between the brain and the muscles. It was first described in the 1860's. In 1975, the Muscular Dystrophy Association took it up as a disease in its program. In 1996, scientists discovered the gene for FA. Initial symptoms of FA include exactly what Linda is experiencing. As time goes by, the symptoms will likely worsen to the point that a cane is necessary, and then a walker, and then a wheelchair. Speech can become incoherent. Other effects can include scoliosis, heart disease, foot deformities, and diabetes, among other things. The rate at which these problems develop and progress is not certain. About 6,000 people have it in the US. In most cases, FA is first seen in children, before the age of twenty. In rare cases, "Late Onset" Friedreich's Ataxia occurs.
How do you get it?
FA is an autosomal recessive disease. About 1 in 100 people are carriers; about 1 in 50,000 people have the disease. FA is due to defects in a gene on chromosome 9 that is responsible for a protein called frataxin. The defects keep the affected cells from making a normal amount of frataxin. Everyone has two copies of the frataxin gene, one inherited from each parent. A person with one defective gene is a carrier, who can then pass it on to his/her children. A person who inherits two defective frataxin genes (one from each parent) will develop FA. So if the two parents are both carriers, there is a 25% chance that the child will develop FA. There's another 50% chance that the child will be a carrier.
What exactly is wrong with the gene?
The specific defect in the gene is a "triplet repeat." This is where the section of DNA is repeated over and over again, from as many as 100 to more than 1,000 times. It is this extra genetic material that interferes with the normal production of frataxin. A person without FA may have a few dozen repeats - that's normal. Anything more than about 35 repeats is a result of FA. Of course each person has two of these chromosomes, each with a certain number of repeats. A normal person would have both chromosomes with a small number of repeats. A carrier would have one chromosome with a large number of repeats. Someone with FA would have both chromosomes with a large number of repeats.
How is it cured?
There is presently no cure for FA. The only treatment involves dealing with the effects and monitoring certain conditions to be sure they don't become life-threatening (i.e., diabetes, heart disease).
How bad is it?
It's difficult to say. It depends on the severity. It usually first occurs in children, who may live another 30 years after symptoms first appear, although life expectancy is getting better as researchers learn more. With late onset FA, the progression of the disease may be slower, although that's not clear.
Where can I find out more?
There are many websites that have information about the disease. Here are a few sites that may be of help:
Muscular Dystrophy Association
Friedreich's Ataxia Research Alliance
National Institute of Neurological Disorders and Stroke