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Madisons Foundation - Moms And Dads In Search Of Needed Support
What
Machado-Joseph disease (MJD) is a rare, progressive genetic disease, characterized by problems with movement and balance (ataxia), abnormal muscle spasms, involuntary eye movements, and difficulties with speech and eating. It is caused by an inherited gene defect that damages cells in the brain and spinal cord, which then leads to the problems with the muscles.Who
MJD is very rare in the general population, but the prevalence is higher in certain areas and ethnic groups, such as people of Portuguese ancestry. Before, MJD was thought to mostly occur in families that are descendents from Portugal and the Azorean islands, but now, MJD has been found to occur all over the world. MJD occurs equally in males and females.Signs and Symptoms
Signs and symptoms usually start occurring between early adolescence to adulthood, from about the ages of 15 to 40. A few individuals may have a later onset. Individuals with MJD can have few or many of the following signs and symptoms. Some characteristics may get progressively worse, while others stay the same over time.
- Ataxia: this means that there are problems with balance and coordinating movements. This can make movements such as walking very difficult to do.
- Muscle problems: the muscles may become weak, like in the arms and legs; some muscles may continue to spasm which can cause an uncomfortable, abnormal muscle tone.
- Some muscles may contract involuntarily which can cause twisting of the body, face, arms, and legs
- Vision and eye problems: there may be blurred vision, double vision (diplopia), abnormal eye movements, and some bulging out of the eyes
- Loss of feeling and sensation, especially in the arms and legs
- Difficulty with speech
- Difficulty with swallowing: this can make a person more prone to lung infections
- Frequent urination
- Some people may have high blood sugar
- Some people have other signs and symptoms such as severe muscle cramping, tremoring (like of the arms and legs), and a feeling of rigidity.
Possible Causes
We have two copies of almost every gene; each copy is inherited from a parent. Machado-Joseph disease is caused by a gene defect in the MJD gene (sometimes this gene is also called ATX3 or SCA3). This disease is an autosomal dominant genetic disease. This means that inheriting one defective copy of the MJD gene from a parent can cause the disease (the other copy of the gene may be normal). Since the parent also has the gene defect, the parent will also be affected as well, however the severity of symptoms can be different. In the MJD gene, part of the DNA reads “CAG” over and over again for a certain number of times. Normally, there are about 14 to 45 repeats of this CAG code. Individuals with Machado-Joseph disease have a gene defect that has too many repeats of CAG (around 55 to 85). This causes an abnormal protein to be made. Areas like the brain are especially sensitive to this abnormal protein and become dysfunctional. These damaged brain cells lead to the abnormal muscle functioning. Muscles are important for many things, from movements to vision to speaking and swallowing. That’s why MJD can cause so many different signs and symptoms. Scientists are now trying to figure out how exactly this abnormal protein damages cells in the brain and spinal cordDiagnosis
In most cases of MJD, there is a family history of the disease. If a parent is affected with MJD, all of his or her children have a 50% chance of inheriting the defective gene. Individuals may be diagnosed with MJD if they show the classical signs and symptoms described above, in most cases when they are between the ages of 20 to 40. The doctor will also ask about the family history, such as who has it, what symptoms are common in that family, and how it generally progressed in individuals in the family. In addition, for people who are already showing signs and symptoms, doctors may perform a genetic test to confirm whether the MJD gene defect is present.Treatment
There is no cure for MJD yet. The treatment mainly consists of supportive treatment to help reduce signs and symptoms and to help make daily activities easier. Physiotherapy can be useful for the ataxia and difficulty with movements. A walker, wheelchair, or other types of aids may also be helpful. There are medications available to help decrease muscle spasms, muscle cramping, and urination problems. Prism glasses or an eye cover can help reduce double vision and blurred vision. A special diet can be helpful for severe swallowing problems. Some individuals may have symptoms similar to Parkinson’s disease, such as rigidity and abnormal posturing. In these cases, medications used for Parkinson’s disease may be helpful. Researchers are currently working on other medications to target the abnormal protein that causes MJD itself.Prognosis
The severity of MJD and age of onset can vary from person to person. Unfortunately, in severe cases, there may a fast progression of signs and symptoms that can be very debilitating and decrease the life expectancy. In other cases, the progression might be much slower and less severe, with a relatively normal life expectancy. Your doctor can give you more information on the prognosis for MJD, based on the age of onset, which signs and symptoms are present, and how they are progressing.Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.Weblinks
Support Groups
Through these two online support groups, you can contact other families with MJD and exchange resources or share your stories.
International Joseph Diseases Foundation
P.O. Box 994268 Redding, CA 96099 USA
Tel: (530) 246-4722 This group provides support, educational links, and other resources for families with MJD.
National Institute of Neurological Disorders and Stroke (NINDS)
This website provides a summary of medical information for MJD and also has a list of links that may be helpful.
Ataxia MJD Research Project, Inc.
This group focuses on trying to fund research for MJD, and has information on recent studies that have been done.
Trinucleotide Repeat Disorders: MJD
This website has a short summary of MJD.
Genetic Diseases, Mazornet Guide: MJD
This website has a summary on MJD and links to other sites.
International Network of Ataxia Friends
This website has links to ataxia support groups and a lot of information under the “medical info and more” link, such as on walking aids, exercise, and transportation for people with ataxia.
National Ataxia Foundation (NAF)
This foundation focuses on support groups, education, and research for ataxias.