Spinocerebellar ataxias (SCAs) are a group of genetic conditions that affect the nervous system.^1,2 SCAs are neurodegenerative conditions, where there are loss of nerve cells (neurons) in the cerebellum of the brain, spinal cord or other parts of the central nervous system. This results in loss of muscle control and coordination (ataxia) and affects movement of arms, legs, hands, eyes, as well as speech. These conditions are progressive, which means the symptoms worsen over time.

There are more than 50 different types of SCAs described in the literature so far.^3,4 The types of SCAs have been named in the order which they are identified (SCA1, SCA2, SCA3…). They have distinct genetic causes and affect different parts of the central nervous system.^1,5 The range of symptoms varies between the different types of SCAs.^1,2,5,6

Information about the individual SCA types may be added to the RARE Portal over time.

Synonyms: episodic ataxia, autosomal dominant hereditary ataxia.

Universal rare disease classifications provide a common language for recording, reporting and monitoring diseases. Please visit the Rare Disease Classifications page for more information about these internationally recognised classifications.

Please refer to the individual SCA types for their OPRHAcodes.

ICD-11: 8A03.16 Spinocerebellar ataxia

Common symptoms of SCAs include loss of muscle coordination and control (ataxia) leading to poor balance, difficulty with walking, difficulty moving limbs (arms, hands and legs), abnormal eye movement, and slurred speech.^1,2 The ataxia typically starts in mid-adulthood, but can also appear during childhood or in old age for some individuals.¹ SCAs are progressive conditions, which means that the symptoms get worse over time.

Depending on the type of SCA, there may be additional symptoms, such as tremors, seizures, muscle weakness, muscle twitching, issues with vision, and hearing loss.^2,6 For some types of SCA, there may be difficulty swallowing (dysphagia), and risk of serious complications such as aspiration pneumonia.² There may also be other symptoms that have not been mentioned here.

Please speak to your medical team to learn more about the symptoms and complications of SCAs.

Rare diseases are often serious and progressive, exhibiting a high degree of symptom complexity, leading to significant disability. Majority of the estimated two million Australians living with a rare disease meet the Australian Government’s definition for disability (in accordance to the Australian Public Service Commission and Australian Bureau of Statistics), and many experience severe and permanent disability impacts. If you or someone you care for is experiencing disability-related impacts from a rare condition, please speak with a health or disability professional for advice. Information about relevant disability support can be found at the RARE Portal’s Disability Support Information page.

SCAs are genetic conditions that are caused by disease-causing genetic variants (changes) in various genes. These genetic variants include single base changes (sequence variants/ a single letter changes in the genetic code), deletions, insertions and duplications.^2,5 For more information on different types of genetic variants, please refer to Centre for Genetics Education: Types of genetic variation.

There are more than 50 different types of SCAs.^3,4 Not all the genes involved in the different types of SCAs have been identified.⁵

SCAs are typically inherited in an autosomal dominant manner, which means that having a genetic variant in just one of the gene copies can result in SCA.^1,2 More information on autosomal dominant inheritance pattern can be found at Centre for Genetics Education: Autosomal dominant inheritance.

If you would like to learn more about the inheritance and impact of this condition, please ask your doctor for a referral to a genetic counsellor. Genetic counsellors are qualified allied health professionals who can provide information and support regarding genetic conditions and testing. More information about genetic counselling can be found at:

• Information on Genetic Services
• The National and State Services pages underneath the ‘Genetic Counselling’ sections listed

Diagnosis of SCAs and the specific SCA type, may be made based on physical examination, medical history including family history, as well as other diagnostic tests such as blood tests, nerve conduction studies, lumbar puncture/spinal tap, neuroimaging and genetic testing.⁷

A differential diagnosis can rule out other conditions that have similar symptoms, such as other types of ataxia, chorea, drug-induced movement disorders, dentatorubral pallidoluysian atrophy and Gersmann-Straussler-Schenker syndrome.² Differential diagnosis can be tricky due to the wide range of symptoms in SCAs.

Please speak to your medical team to learn more about the available diagnostic pathways for a specific type of SCA.

There is currently no curative treatment for SCAs but there is on-going research for disease-modifying therapies.^5,7 Treatment is targeted at managing symptoms (symptomatic management) and involves a multidisciplinary care team. This may include physiotherapy, occupational therapy, speech therapy, assistive equipment, mobility and medical aids.^2,7 Information on equipment and assistive technology can be found at The Loop – Your Neuromuscular Resource Hub: Equipment.

There may also be medication to help with seizures, tremors, muscle spasms and pain.^2,8 Regular monitoring of disease progression is recommended.^1,8

Please speak to your medical team to learn more about the possible treatment or management options for your condition. Treatment will depend on an individual’s specific condition and symptoms. It is also important to stay connected to your medical team so that you can be made aware of any upcoming clinical trial opportunities.

Healthcare professionals involved in the treatment of SCAs may include general practitioners (GP), geneticists, neurologists, radiologists, ophthalmologists, occupational therapists, physiotherapists, speech therapists, and psychologists.^2,7 The need for different healthcare professionals may change over a person’s lifetime and extend beyond those listed here.

Clinical care for rare diseases often involves a multidisciplinary team of medical, care and support professionals. Please note that the information provided here is as a guide and that RVA does not necessarily monitor or endorse specific clinics or health experts.

For many rare diseases, palliative care services may be relevant and useful. Palliative care services are available for people (adults, children and their families) living with a life-limiting illness and is not only for end-of-life care. It can also help at any stage of illness from diagnosis onwards, and will look different for different people. Palliative care services provide assistance, support, resources and tools to help people manage their illness and the symptoms, ease pain, and improve comfort and quality of life. If this is relevant to you and you wish to find out more information about palliative care and how it can help you, please visit:

• Australian Institute of Health and Welfare: Palliative care Overview
• Australian Government Department of Health, Disability and Ageing: Palliative care
• Palliative Care Australia

We are not aware of any published clinical care guidelines for SCAs as whole in Australia. If you know of any relevant care guidelines, please let us know via the Contribute page.

The following guidance is available from international experts outside Australia; however, there may be information that is not relevant or applicable to the Australian context, and may not be up to date:

• Guidelines on the diagnosis and management of the progressive ataxias (United Kingdom) – developed by a Guideline Development Group, consisting of ataxia specialist neurologists and representatives of Ataxia UK (including patients and carers) and published in 2019; these guidelines focus on the progressive ataxias, including SCA.

Individuals living with rare diseases may have complex medical issues and disabilities, which are not always visible. It is often useful to refer to their medical history as well as personal information such as a medical card, doctor’s letter, or if available, a rare disease passport, for relevant information.

In addition, individuals, their parents, families and carers often develop extensive expertise on their specific rare disease. It is important to recognise that they can contribute valuable knowledge about their rare condition. Rare diseases often impact individuals differently, so it’s important to consider a person’s lived experience.

It may be important to consider the following when managing individuals living with SCA at emergency departments/services:

• individuals with SCA have ataxia, which can affect their coordination, movement, speech and vision
• individuals may have difficulty communicating if their speech is affected
• individuals may have difficulty swallowing and may be at risk of aspiration pneumonia
• the range of SCA clinical features depends on the type of SCA. Some individuals may have seizures, tremors, muscle weakness or hearing loss

Murdoch Children’s Research Institute: Australian Cerebellar Ataxia Registry (CARe) research project is a contact list of individuals with cerebellar ataxia who are willing to be contacted for participation in research studies and clinical trials.

There are specific considerations around participating in rare disease research, including clinical trials. It is important to be mindful of issues such as data privacy, research ethics, consent and differences in research regulations between Australia and other countries. For more information, please visit the RARE Portal’s Considerations for Participating in Health and Medical Research page.

If you are interested in finding clinical trials for your condition, please visit the following websites; however, there may not be any clinical trials available:

• Australian Clinical Trials
• ClinicalTrials.gov

It is best to discuss your interest in research, including clinical trials,  with your medical team to determine suitability and eligibility.

Australian Organisations:

Cerebellar Ataxia Australia Inc.(previously known as Spinocerebellar Ataxia Australia)
Website: https://www.scars.org.au/

MJD Foundation
Website: https://mjd.org.au/

The MJD Foundation is a grassroots community organisation working in partnership with Aboriginal & Torres Strait Islander Australians living with Machado-Joseph Disease (MJD) and Spinocerebellar Ataxia Type 7 (SCA7) across Northern and Central Australia. MJD Foundation’s ‘Our Way’ approach is based on a strong Aboriginal Community Worker two-way engagement model. Their work areas include education, research, community services, clinical services, advocacy/influence and governance/management.

International Organisation:

National Ataxia Foundation (United States of America)
Website: https://www.ataxia.org/

Please note that RVA does not monitor or endorse each group/organisation’s operational governance and activities. When engaging with a group, please consider the information on the RARE Portal’s Finding Helpful Peer and Community Supports page.

SCAs vary between individuals, and each person’s experience is unique.

Personal stories shared with RVA:

• Adam’s Story
• Beck’s Story

If you would like to share your personal story with RVA, please visit the Rare Voices Australia: Share Your Story page. RVA will consider your story for publishing on our website and inclusion on the RARE Portal.

For information on available government and social services that provide support for individuals with a rare disease, please visit the National and State Services pages.

People living with a rare disease often face unique challenges such as diagnostic delays, misdiagnoses, limited treatment options, and limited access to rare disease specialists and support. These challenges may impact people’s emotional wellbeing and quality of life. Many find it helpful to seek mental health and wellbeing support to cope with ongoing stress and uncertainty. Connecting with people who have shared experiences through a support group may also be helpful. Information about relevant mental health and wellbeing support can be found at:

• Mental Health and Wellbeing Support for Australians Living with a Rare Disease
• The National and State Services pages underneath the ‘Mental Health’ sections listed

Further information on SCAs can be found at:

• National Organization for Rare Disorders (NORD): Spinocerebellar Ataxia (video)

Movement Disorder Society of Australia and New Zealand (MDSANZ) – a not-for-profit organisation with membership open to medical personnel who have a clinical or research interest in movement disorders

This page has been developed by Rare Voices Australia (RVA)’s RARE Portal team.

If you are aware of any additional information that may benefit stakeholders with an interest in this page, or if you notice any broken links or inaccurate information, please let us know via the Contribute page.