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Disease Profile

Spinocerebellar ataxia 29

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

SCA29; Spinocerebellar ataxia type 29; Cerebellar vermis aplasia;


Congenital and Genetic Diseases; Nervous System Diseases


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 208513

An autosomal dominant cerebellar ataxia type I that is characterized by very slowly progressive or non-progressive ataxia, dysarthria, oculomotor abnormalities and intellectual disability.

Spinocerebellar ataxia type 29 (SCA29) prevalence is unknown. More than 50 cases have been reported in the literature to date.

Clinical description
SCA29 presents at birth, or shortly after, with manifestations including very slowly progressive or non-progressive gait and limb ataxia causing delayed walking and frequent falling in children. Mild developmental delay, learning difficulties, and language dysfunction are frequently reported. Other manifestations include nystagmus, dysarthria, dysmetria, and dysdiadochokinesia. Affected patients occasionally present with intention tremor, dystonia, and migraine headaches. Although the disease course is not well established, it appears to range from non-progressive or very slowly progressive ataxia (that does not affect ambulation) to progressively disabling ataxia. A slight improvement in cerebellar signs has been reported in some cases over time.

SCA29 is due to mutations in the ITPR1 gene (3p26.1), which is also the causal gene of SCA15.

Diagnostic methods
Diagnosis is based on the characteristic clinical findings and molecular genetic testing. As the manifestations of SCA29 are not specific, diagnosis is only confirmed with the finding of a mutation in the ITPR1 gene.

Differential diagnosis
Differential diagnosis includes other types of autosomal dominant cerebellar ataxia.

Antenatal diagnosis
Antenatal diagnosis is possible in families with a known mutation.

Genetic counseling
SCA29 is inherited autosomal dominantly, occasionally autosomal recessively, and genetic counseling is possible.

Management and treatment
There is no cure for SCA29 and treatment is supportive. Annual neurological examinations are recommended to monitor disease progression.

Disease progression is very slow, but precise prognosis is unknown.

Visit the Orphanet disease page for more resources.


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.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Delayed fine motor development
Delayed gross motor development
Delayed motor skills
Delayed speech and language development
Deficiency of speech development
Delayed language development
Delayed speech
Delayed speech acquisition
Delayed speech development
Impaired speech and language development
Impaired speech development
Language delay
Language delayed
Language development deficit
Late-onset speech development
Poor language development
Speech and language delay
Speech and language difficulties
Speech delay

[ more ]

Difficulty articulating speech
Lack of coordination of movement
Gait ataxia
Inability to coordinate movements when walking
Intention tremor
30%-79% of people have these symptoms
Abnormal saccadic eye movements
Cerebellar atrophy
Degeneration of cerebellum
Cerebellar vermis atrophy
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment

[ more ]

Delayed social development
Difficulty performing quick and alternating movements
Generalized hypotonia
Decreased muscle tone
Low muscle tone

[ more ]

Involuntary, rapid, rhythmic eye movements
Oculomotor apraxia
5%-29% of people have these symptoms
Global developmental delay
Visual fixation instability
Percent of people who have these symptoms is not available through HPO
Agenesis of cerebellar vermis
Autosomal dominant inheritance
Broad-based gait
Wide based walk
Congenital onset
Symptoms present at birth
Limb ataxia
Motor delay
Nonprogressive cerebellar ataxia


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


    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

      Social Networking Websites

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        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 29. Click on the link to view a sample search on this topic.