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Causes
Spinocerebellar ataxia is caused by a genetic defect that involves an expansion in the DNA sequence called a trinucleotide-repeat-expansionfor scatypes 1-3, 6-10, 12, and 17. In general, the type of DNA expansion involves three DNA letters (nucleotide). In these cases, the sequence cag-abbreviation(C=cytosine, A=adenine, G=guanine) is repeated above the normal repeat length. The normal repeat number differs for different types, as does the expanded repeat sizes. By repeating this sequence of DNA too many times, function of the protein it encodes can be disrupted. Other types of repeat expansions that cause SCA have been discovered. For example, SCA10 involves an ATTCT repeat expansion of the SCA10 gene and SCA8 involves an expansion in the SCA8 gene with the nucleotides ctgrepeated. Finally, SCA14 involves a mutation in a gene that does not involve a trinucleotiderepeat expansion.
The most common types are SCA1 (6%), SCA2 (14%), SCA3 (21%), SCA6 (15%), SCA7 (5%), and SCA8 (2-5%). Age of onset for all of these types is on average from 20-30 years of age except for SCA6, which usually occurs between the ages of 40 and 50. People with SCA8 usually develop symptoms between in their late 30s. SCA2 patients usually develop dementiaand slow eye movements. SCA8, which has a normal life-span, and SCA1 patients are both characterized as having active reflex. SCA7 patients develop visual loss. SCA3 is also known as machado-joseph-disease.
In SCA types 1-3 and 7, there can be an earlier age of onset with increased severity (called anticipation) as the defect is passed from one generation to the next. This means that children can be more severely affect at an earlier age than their affected parent. The size of the repeat of nucleotides in the affected genes is thought to correlate with the severity and age of onset in offspring. As the repeat size expands, the severity worsens and age of onset becomes earlier compared with the affected parent. However, repeat size does not predict the exact age of onset or the specific symptoms that will develop.
Penetrance refers to the likelihoodthat individuals with a genetic defect will develop the disease. In spinocerebellar ataxia, the penetranceis quite high; however, there are rare cases in which people do not develop symptoms. The reason for the lack of complete penetrance is currently unknown.
Affected individuals initially develop poor coordination of movement, which is the definition of ataxia. Developing poor movement coordination in patients is manifested clinically by difficulty in walking, abnormalities in hand or eye movements, and speech difficulties. Generally, the age of onset is usually after 18 years old, making it typically an adult-onset disorder. The severity of progressive degenerationdepends primarily on the underlying defect.
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Is restless leg syndrome connected to ataxia?
It is one of the symptoms of Spinocerebellar Ataxia.
Was there ever a case of spinocerebellar ataxia in the Philippines?
Yes. I am one of them. My name is Jessamine and I have a spinocerebellar atrophy.
Is spinocerebellar ataxia as dangerous?
yes it is there is no cure for this disease
What causes spinocerebellar ataxia?
Usually some form of damage to the cerebellum, for example a stroke that causes the death of some of the cerebellum.
Who was the first victim of Spinocerebellar ataxia?
Dorian Van Dabooblin. Your welcome.
How many people have spinocerebellar ataxia?
well in general, there are 150,000 in the US that have ataxia. for more information please visit www.ataxia.org graduate student Ataxia project
What is the treatment for spinocerebllar ataxia?
There is no cure for spinocerebellar ataxia. There is also no treatment to slow the progression of the disease. Treatment, therefore, remains supportive.
What is Olivopontocerebellar atrophy?
hereditary OPCA is caused by the inheritance of a defective gene. Several genes have been identified. The two most common are known as SCA-1 and SCA-2 (SCA stands for spinocerebellar ataxia ).
Is spinocerebellar ataxia considered MS?
No. MS (Multiple Sclerosis) and Spinocerebellar Ataxia (SCA) are different diseases. MS affects the degeneration of "myelin", which is the coating around neurons responsible for ensuring that signals travel smoothly. SCAs (there are a handful) result in the degeneration of different regions of the brain, depending on the particular type of SCA. Some SCAs are inheritedly genetically where if a parent is affected, a child would have a 50% chance of inheriting the disease. SCAs are sometimes misdiagnosed as MS. Hope that helps.
What is spinocerebellar degeneration disease?
What are Spinocerebellar Degeneration Disease?Ataxia often occurs when parts of the nervous system that control movement are damaged. People with ataxia experience a failure of muscle control in their arms and legs, resulting in a lack of balance and coordination or a disturbance of gait. While the term ataxia is primarily used to describe this set of symptoms, it is sometimes also used to refer to a family of disorders. It is not, however, a specific diagnosis. Most disorders that result in ataxia cause cells in the part of the brain called the cerebellum to degenerate, or atrophy. Sometimes the spine is also affected. The phrases cerebellar degeneration and spinocerebellar degeneration are used to describe changes that have taken place in a person's nervous system; neither term constitutes a specific diagnosis. Cerebellar and spinocerebellar degeneration have many different causes. The age of onset of the resulting ataxia varies depending on the underlying cause of the degeneration. Many ataxias are hereditary and are classified by chromosomal location and pattern of inheritance: autosomal dominant, in which the affected person inherits a normal gene from one parent and a faulty gene from the other parent; and autosomal recessive, in which both parents pass on a copy of the faulty gene. Among the more common inherited ataxias are Friedreich's ataxia and Machado-Joseph disease. Sporadic ataxias can also occur in families with no prior history. Ataxia can also be acquired. Conditions that can cause acquired ataxia include stroke, multiple sclerosis, tumors, alcoholism, peripheral neuropathy, metabolic disorders, and vitamin deficiencies. Is there any treatment?There is no cure for the hereditary ataxias. If the ataxia is caused by another condition, that underlying condition is treated first. For example, ataxia caused by a metabolic disorder may be treated with medications and a controlled diet. Vitamin deficiency is treated with vitamin therapy. A variety of drugs may be used to treat gait and swallowing disorders. Physical therapy can strengthen muscles, while special devices or appliances can assist in walking and other activities of daily life. What is the prognosis?The prognosis for individuals with ataxia and cerebellar/spinocerebellar degeneration varies depending on its underlying cause. What research is being done?The NINDS supports and conducts a broad range of basic and clinical research on cerebellar and spinocerebellar degeneration, including work aimed at finding the cause(s) of ataxias and ways to treat, cure, and, ultimately, prevent them. Scientists are optimistic that understanding the genetics of these disorders may lead to breakthroughs in treatment.
What is the role of genetic testing in spinocerebellar ataxia?
Genetic testing of at-risk family members can be performed when an affected individual has a known genetic mutation. Testing of high-risk family members without symptoms raises many issues.
How can you treat Spinocerebellar ataxia?
Hi my name is Shig Hamachi I have spinocerebellar ataxia SCA6. My birth date is 3/29/1941. I am responding to this question because I used to get severe cramps in my fingers, legs, feet and had stiffness and tremors when I got out of bed in the morning. I started taking 1500 mg calcium magnesium with 400iu vitamin D and all my cramps, stiffness and tremor went away. I had a calcium deficiency because my body cannot channel calcium properly. This caused my ataxia because my cells in the cerebellum died because of lack of calcium.
