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Disease Profile

Spinocerebellar ataxia 23

Prevalence
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.

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US Estimated

Europe Estimated

Age of onset

Adult

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ICD-10

G11.2

Inheritance

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

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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.

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X-linked
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.

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

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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.

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Not applicable

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Other names (AKA)

SCA23; Spinocerebellar ataxia type 23

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

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

Orpha Number: 101108

Definition
Spinocerebellar ataxia type 23 (SCA23) is a very rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I; see this term). It is characterized by gait ataxia, dysarthria, slowed saccades, ocular dysmetria, Babinski sign and hyperreflexia.

Epidemiology
This subtype has only been described in 4 Dutch families. Age of onset is from 43 to 56 years.

Clinical description
The clinical features, head magnetic resonance imaging (MRI), and neuropathological findings are indistinguishable from other SCA subtypes.

Etiology
SCA23 maps to chromosome region 20p12.3-p13 and missense mutations in the prodynorphin PDYN gene appear to cause the disease.

Prognosis
Prognosis may be good in some cases. Disease progression can be slow. Wheelchair dependence can occur more than 20 years after symptomatic disease onset.

Visit the Orphanet disease page for more resources.

Symptoms

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:
HPO ID
80%-99% of people have these symptoms
Gait ataxia
Inability to coordinate movements when walking
0002066
Hyperreflexia
Increased reflexes
0001347
Limb ataxia
0002070
Progressive cerebellar ataxia
0002073
30%-79% of people have these symptoms
Babinski sign
0003487
Dysarthria
Difficulty articulating speech
0001260
Dysmetria
Lack of coordination of movement
0001310
Impaired distal vibration sensation
0006886
Impaired proprioception
0010831
Slow saccadic eye movements
Slow eye movements
0000514
5%-29% of people have these symptoms
Agenesis of corpus callosum
0001274
Tremor
0001337
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Cerebellar atrophy
Degeneration of cerebellum
0001272
CNS demyelination
0007305
Impaired vibration sensation in the lower limbs
Decreased lower limb vibratory sense
Decreased vibratory sense in lower limbs
Decreased vibratory sense in the lower extremities
Decreased vibratory sense in the lower limbs
Diminished vibratory sensation in the legs

[ more ]

0002166
Neuronal loss in central nervous system
Loss of brain cells
0002529
Polyneuropathy
Peripheral nerve disease
0001271
Sensorimotor neuropathy
Nerve damage causing decreased feeling and movement
0007141
Slow progression
Signs and symptoms worsen slowly with time
0003677

Diagnosis

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.

    Organizations

    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

      Learn more

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