National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Spinocerebellar ataxia 31


Other Names:
SCA31; Spinocerebellar ataxia type 31; Spinocerebellar ataxia 16q22-linked
Categories:
This disease is grouped under:
The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 217012

Definition
An autosomal dominant cerebellar ataxia type III that is characterized by the late-onset of ataxia, dysarthria and horizontal gaze nystagmus, and that is occasionally accompanied by pyramidal signs, tremor, decreased vibration sense and hearing difficulties.

Epidemiology
Spinocerebellar ataxia type 31 (SCA31) is the third most common form of ADCA in Japan, where more than 20 families have been reported to date. It is rarely found in other Asian countries and is extremely rare in Western countries.

Clinical description
The mean age of disease onset is 58 years but it can present between the ages of 8 to 83 years. Ataxia, dysarthria, and horizontal gaze nystagmus are the common manifestations of SCA31, and the disease duration can be more than 10 years. Less common manifestations include pyramidal signs, tremor, decreased vibration sense, hearing difficulties, and blepharospasm

Etiology
SCA31 is due to non-coding pentanucleotide repeat expansions in the BEAN1 gene (16q21), encoding protein BEAN1.

Diagnostic methods
Diagnosis is based on the characteristic clinical findings and molecular genetic testing. As the manifestations of SCA31 are not specific, diagnosis is only confirmed with the finding of a mutation in the BEAN1 gene

Differential diagnosis
Differential diagnosis includes other types of ADCA.

Genetic counseling
SCA31 is inherited autosomal dominantly with incomplete penetrance and genetic counseling is possible. Genetic counseling should be proposed to individuals having the disease-causing mutation informing them that there is 50% risk of passing the mutation to offspring.

Management and treatment
There is no cure for SCA31 and treatment is supportive. Physical therapy, as well as the use of canes and walkers, should be offered in order to maximize strength and maintain activity. Wheelchairs are eventually necessary. Speech therapy and communication devices may be useful to those with dysarthria. Dysphagia should be monitored to decrease the risk of aspiration pneumonia. In those with vertigo, vestibular suppressants may be beneficial. Annual neurological examinations are recommended to monitor disease progression.

Prognosis
Disease progression is very slow. Life expectancy is not reduced but the quality of life can be significantly affected. According to recent reports, patients can become wheelchair bound at age of 79 years, and died at age of 89 years.

Visit the Orphanet disease page for more resources.
Last updated: 1/1/2020

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Cerebellar atrophy
Degeneration of cerebellum
0001272
Dysarthria
Difficulty articulating speech
0001260
Gait ataxia
Inability to coordinate movements when walking
0002066
30%-79% of people have these symptoms
Gaze-evoked horizontal nystagmus 0007979
Hyporeflexia
Decreased reflex response
Decreased reflexes
[ more ] 		0001265
Late onset 0003584
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
5%-29% of people have these symptoms
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Hyperactive deep tendon reflexes 0006801
Impaired vibratory sensation
Decreased vibration sense
Decreased vibratory sense
Diminished vibratory sense
Impaired vibratory sense
[ more ] 		0002495
Sensorineural hearing impairment 0000407
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
Tremor 0001337
Percent of people who have these symptoms is not available through HPO
Ataxia 0001251
Autosomal dominant inheritance 0000006
Limb ataxia 0002070
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Spinocerebellar Ataxia: Making an Informed Choice about Genetic Testing is a booklet providing information about spinocerebellar ataxia and is available as a PDF document on the University of Washington Medical Center Web site. Click on the title above to view this resource.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Spinocerebellar ataxia 31. Click on the link to view a sample search on this topic.

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