Rare Oncology News

Disease Profile

Cap myopathy

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 / 1 000 000

< 331

US Estimated

< 514

Europe Estimated

Age of onset

Infancy

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ICD-10

G71.2

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)

Cap disease; Congenital myopathy with caps

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

Cap myopathy is a disorder that primarily affects skeletal muscles, the muscles that the body uses for movement. People with cap myopathy have muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body, but they are most severely affected in the muscles of the face, neck, and limbs. The muscle weakness, which begins at birth or during childhood, can worsen over time. The name cap myopathy comes from characteristic abnormal cap-like structures that can be seen in muscle cells when muscle tissue is viewed under a microscope. The severity of cap myopathy is related to the percentage of muscle cells that have these caps. Individuals in whom 70 to 75 percent of muscle cells have caps typically have severe breathing problems and may not survive childhood, while those in whom 10 to 30 percent of muscle cells have caps have milder symptoms and can live into adulthood. Cap myopathy can be caused by mutations in the in the ACTA1, TPM2, or TPM3 genes. This condition follows an autosomal dominant manner of inheritance, however, most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family.[1]

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
30%-79% of people have these symptoms
High palate
Elevated palate
Increased palatal height

[ more ]

0000218
Long face
Elongation of face
Increased height of face
Increased length of face
Vertical elongation of face
Vertical enlargement of face
Vertical overgrowth of face

[ more ]

0000276
Motor delay
0001270
Reduced tendon reflexes
0001315
5%-29% of people have these symptoms
Aortic root aneurysm
Bulge in wall of root of large artery that carries blood away from heart
0002616
Central hypoventilation
0007110
Difficulty climbing stairs
Difficulty walking up stairs
0003551
Difficulty running
0009046
Easy fatigability
0003388
Facial palsy
Bell's palsy
0010628
Fatiguable weakness of proximal limb muscles
0030200
Frequent falls
0002359
Generalized amyotrophy
Diffuse skeletal muscle wasting
Generalized muscle degeneration
Muscle atrophy, generalized

[ more ]

0003700
Generalized hypotonia
Decreased muscle tone
Low muscle tone

[ more ]

0001290
Gowers sign
0003391
Increased variability in muscle fiber diameter
0003557
Lower limb amyotrophy
0007210
Lower limb muscle weakness
Lower extremity weakness
Lower limb weakness
Muscle weakness in lower limbs

[ more ]

0007340
Lumbar hyperlordosis
Excessive inward curvature of lower spine
0002938
Mitral valve prolapse
0001634
Nasal speech
Nasal voice
0001611
Pectus excavatum
Funnel chest
0000767
Pes planus
Flat feet
Flat foot

[ more ]

0001763
Pes valgus
0008081
Poor head control
0002421
Reduced systolic function
0006673
Sinus tachycardia
0011703
Thoracic scoliosis
0002943
Toe walking
Toe-walking
0040083

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

  • Genetics Home Reference contains information on Cap myopathy. This website is maintained by the National Library of Medicine.

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.
  • 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 Cap myopathy. Click on the link to view a sample search on this topic.

References

  1. Cap myopathy. Genetics Home Reference (GHR). April 2012; https://ghr.nlm.nih.gov/condition/cap-myopathy. Accessed 9/23/2013.