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A collection of resources for individuals and families affected by SCA17.
Spinocerebellar Ataxia type 17 (SCA17) is caused by a genetic mutation that is passed on from parents to their children. SCA17 leads to problems with balance and coordination, as well as dementia, and involuntary movements such as chorea or dystonia.
For complete information about symptoms, diagnosis, and treatment of Ataxia, visit our What is Ataxia? page. This page contains NAF’s resources that are specific to SCA17.
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Presented by Dr. Pravin Khemani
This webinar covers the causes and symptoms of SCA17, the typical diagnostic journey for those affected, and what to expect for clinical care.
NAF offers webinars on many topics to help you live better with Ataxia. Visit www.ataxia.org/webinars to find other helpful presentations.
Participating in a research study or clinical trial is one way to take an active role in furthering understanding and treatment of Ataxia. It is also a way to get access to new treatment options before they are widely available. To find studies that are enrolling patients, visit our Help Develop New Treatments page.
Spinocerebellar Ataxia type 17 (SCA17) is a rare neurodegenerative disorder. It is caused by mutations in the TBP gene. SCA17 is very rare worldwide. The estimated prevalence of SCA17 is less than 1 in 1,000,000 people, with approximately 100 families with SCA17 reported in the scientific literature.
There is some evidence that the prevalence of SCA17 might be underestimated, as the symptoms of SCA17 appear very similar to those of Huntington Disease. In fact, an older name for SCA17 was “Huntington Disease-Like 4”.
Like many other forms of Ataxia, SCA17 is marked by poor balance and coordination. In fact, the word Ataxia means incoordination. There can also be problems coordinating muscles that control speech and swallowing. People with SCA17 also develop dementia and involuntary movement symptoms, such as chorea or dystonia.
Other common SCA17 symptoms include pyramidal signs, psychiatric symptoms, rigid muscles, and Parkinsonism. These symptoms may be mistaken for other neurodegenerative disorders, such as Huntington Disease, Parkinson Disease, ALS, or Frontotemporal Dementia.
SCA17 symptoms usually begin around age 30, with most cases occurring in people between the ages of 19 and 48. However, there have been cases of SCA17 occurring in people as young as 3 years old and as old as 75 years old.
The severity of symptoms also varies considerably between people, even within families. SCA17 symptoms are progressive. People with SCA17 may need to use a wheelchair after 5-15 years of experiencing symptoms. SCA17 is a life-shortening condition. Treatments such as mental health support, physiotherapy, occupational therapy, and speech-language therapy can significantly improve the lives of people with SCA17. Some medications may be helpful for symptom management.
SCA17 is an inherited genetic disorder. It is caused by an abnormality of a single gene called the TBP gene. The abnormality can be passed from generation to generation by family members who carry it. Males and females are equally likely to inherit the genes that cause SCA17.
Genetic diseases like SCA17 occur when one of the body’s 20,000 genes does not work properly. Genes are microscopic structures within the cells of our bodies that contain instructions for every SCA17 a person inherits from his or her parents. Two copies of each gene are inherited; one copy from the mother and one from the father. SCA17 is an autosomal dominant disease, meaning that someone will develop symptoms if they inherit at least one mutated copy of the TBP gene. Each child of someone with SCA17 has a 50% chance of inheriting the gene that causes SCA17.
In the case of SCA17, it is caused by a mutation called a CAG repeat expansion in TBP gene. Whether or not you develop SCA17 symptoms depends on how many repeats you have.
More CAG repeats are associated with an earlier age of onset of SCA17 symptoms. The number of repeats can sometimes grow between generations, a phenomenon we call “genetic anticipation”. Due to genetic anticipation, each generation of a family with SCA17 may experience their first symptoms earlier than the previous generation.
Gene tests can be performed for diagnostic purposes to determine what kind of Ataxia is within a person or family. Genetic testing can also be done, in some circumstances, even before there are symptoms, to determine whether a person carries the abnormal gene or genes that cause Ataxia. This is called predictive or presymptomatic testing. A gene test can also be used to determine whether a fetus has an abnormal Ataxia gene. This is called prenatal testing. Anyone who is considering a predictive or prenatal test should consult with a genetic counselor to discuss the reasons for the test, the possible outcomes, and how those outcomes might affect the person emotionally, medically, or socially.
A neurologic examination can determine whether a person has symptoms typical of SCA17. A neurologist is often the most helpful specialist in recognizing symptoms and diagnosing the disease that causes Ataxia. There are several potential follow-up tests. MRI brain imaging is often used to confirm cerebellar atrophy or degeneration. Clinical exams are performed to measure various movement, behavioral, and speech-related symptoms. However, a specific diagnosis of SCA17 ataxia can only be made by a genetic test.
SCAsource provides Ataxia research news, directly from researchers to the Ataxia community. Visit SCAsource to see their full collection. Here is a collection of articles about Ataxia Type Here.
Written by Tala Ortiz Edited by Dr. Larissa Nitschke Repeat-associated non-AUG (RAN) translation in CAG repeat expansion diseases is toxic to cells and causes them to die. The Jain group Read More…
Written by Dr. Sriram Jayabal Edited by Dr. Ray Truant A potential new pathway for SCA17: gene therapy that in mice restores a critical protein deficit protects brain cells from Read More…
Ataxias can occur due to a multitude of reasons. One way a patient might acquire ataxia is from an accident or an injury – not as a result of genetics. Read More…
The instructions our bodies need to grow and function are contained in our genes. These instructions are made up of tiny structures called nucleobases. There are four types of nucleobases Read More…
Written by Dr. Sriram Jayabal Edited by Dr. David Bushart Eye movement deficits occur ubiquitously in spinocerebellar ataxias, even at early disease states, highlighting their clinical importance. Imagine the different Read More…
Written by Dr. Laura Bowie Edited by Dr. Hayley McLoughlin Researchers use genetics to find new pathways that impact the onset of polyglutamine disease symptoms The cells of the human body are Read More…
