Rare Gastroenterology News

Disease Profile

Spinocerebellar ataxia 7

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.
1-9 / 1 000 000

331 - 2,979

US Estimated

1-9 / 1 000 000

514 - 4,622

Europe Estimated

Age of onset

Infancy

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ICD-10

G11.8

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)

SCA7; Spinocerebellar ataxia type 7; Olivopontocerebellar atrophy 3;

Categories

Congenital and Genetic Diseases; Eye diseases; Nervous System Diseases

Summary

Spinocerebellar ataxia 7 (SCA7) is an inherited disease of the central nervous system that leads to impairment of specific nerve fibers carrying messages to and from the brain, resulting in degeneration of the cerebellum (the coordination center of the brain). SCA7 differs from most other forms of SCA in that visual problems, rather than poor coordination, are generally the earliest signs of the disease. Affected individuals have progressive changes in vision (which can result in blindness); symptoms of ataxia; slow eye movements; and mild changes in sensation or reflexes. Later symptoms include loss of motor control, unclear speech (dysarthria), and difficulty swallowing (dysphagia).[1] Onset in early childhood or infancy has an especially rapid and aggressive course often associated with failure to thrive and regression of motor milestones.[2] SCA7 is caused by mutations in the ATXN7 gene and is inherited in an autosomal dominant manner.[2] Treatment is generally symptomatic and supportive.

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
100% of people have these symptoms
Dysarthria
Difficulty articulating speech
0001260
Dysmetria
Lack of coordination of movement
0001310
Hyperreflexia
Increased reflexes
0001347
80%-99% of people have these symptoms
Cone/cone-rod dystrophy
0000548
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty

[ more ]

0002015
30%-79% of people have these symptoms
Babinski sign
0003487
Cerebellar atrophy
Degeneration of cerebellum
0001272
Cerebral atrophy
Degeneration of cerebrum
0002059
Congestive heart failure
Cardiac failure
Cardiac failures
Heart failure

[ more ]

0001635
Dysdiadochokinesis
Difficulty performing quick and alternating movements
0002075
Failure to thrive
Faltering weight
Weight faltering

[ more ]

0001508
Feeding difficulties
Feeding problems
Poor feeding

[ more ]

0011968
Global developmental delay
0001263
Mental deterioration
Intellectual deterioration
Progressive cognitive decline
Cognitive decline, progressive
Cognitive decline

[ more ]

0001268
Motor delay
0001270
Muscle weakness
Muscular weakness
0001324
Neonatal hypotonia
Low muscle tone, in neonatal onset
0001319
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Ophthalmoplegia
Eye muscle paralysis
0000602
Orofacial dyskinesia
0002310
Restless legs
0012452
Sensory impairment
0003474
Visual loss
Loss of vision
Vision loss

[ more ]

0000572
5%-29% of people have these symptoms
Blindness
0000618
Hemeralopia
Day blindness
0012047
Macular degeneration
0000608
Photophobia
Extreme sensitivity of the eyes to light
Light hypersensitivity

[ more ]

0000613
Psychosis
0000709
1%-4% of people have these symptoms
Optic atrophy
0000648
Progressive cerebellar ataxia
0002073
Tremor
0001337
Percent of people who have these symptoms is not available through HPO
Abnormality of extrapyramidal motor function
0002071
Autosomal dominant inheritance
0000006
Chorea
0002072
Genetic anticipation with paternal anticipation bias
0003744
Olivopontocerebellar atrophy
0002542
Pigmentary retinopathy
0000580
Progressive visual loss
Progressive loss of vision
Progressive vision loss
Progressive visual impairment
Slowly progressive visual loss
Vision loss, progressive
Visual loss, progressive

[ more ]

0000529
Slow saccadic eye movements
Slow eye movements
0000514
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
Supranuclear ophthalmoplegia
0000623

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.

    Treatment

    Unfortunately, there is no cure for spinocerebellar ataxia 7 (SCA7). Management of affected individuals is generally supportive because there is currently no known treatment to delay or stop the progression of the disease. Exercise and/or physical therapy has not been shown to help with incoordination or muscle weakness, but individuals with SCA7 should try to maintain active. Canes and walkers can help prevent falls. Modification of the home with conveniences such as grab bars, raised toilet seats, and ramps to accommodate motorized chairs may be necessary. Speech therapy and communication devices such as writing pads and computer-based devices may benefit those with dysarthria (difficulty speaking). Weighted eating utensils and dressing hooks can help maintain a sense of independence. When dysphagia (difficulty swallowing) becomes troublesome, video esophagrams (a study using video x-rays of the esophagus) can identify the consistency of food least likely to trigger aspiration.[2]

    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

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • 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 7. Click on the link to view a sample search on this topic.

          References

          1. Spinocerebellar ataxia type 7 (SCA7). National Ataxia Foundation. November 2008; https://www.ataxia.org/pdf/NAF%20Web%20Content%20Publication%20SCA7.pdf. Accessed 7/12/2011.
          2. Garden G. Spinocerebellar Ataxia Type 7. GeneReviews. December 20, 2012; https://www.ncbi.nlm.nih.gov/books/NBK1256/. Accessed 9/17/2014.

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