Rare Oncology News

Disease Profile

Ring chromosome 22

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

Q93.2

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.

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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)

Chromosome 22 ring; Ring 22; R22

Categories

Chromosome Disorders; Congenital and Genetic Diseases

Summary

Ring chromosome 22 is a rare condition caused by having an abnormal chromosome 22 that forms a ring. In this chromosome abnormality, a segment on the short (p) arm and a segment on the long (q) arm of 22 are missing. The amount of material lost varies from person to person. The remaining ends of chromosome 22 have joined together to make a ring shape. Chromosome 22 is an acrocentric chromosome, meaning that the centromere is near one end, creating a very small short (p) arm that does not contain genes that are relevant to development. Thus, only the lost genes on the long (q) arm matter. Knowing the breakpoint in the long arm is likely more helpful. Most cases are sporadic (happen by chance) and occur in people with no history of the condition in their family.[1]

Symptoms

The associated signs and symptoms depend largely on where the breakpoint occurs on chromosome 22 and how much genetic material has been lost on the long (q) arm. Genetic material lost on the short (p) arm is usually irrelevant and does not cause physical or intellectual features. The breakpoints on the long (q) arm can be difficult to determine; but in ring chromosome 22, they are most likely to happen somewhere in the terminal segment of the distal band 22q13.[2]

In general, there is limited information on how chromosome abnormalities like ring chromosome 22 impact growth and development. Since each abnormality is usually so rare, there are few cases to learn from, let alone conduct research. It is generally difficult to say what the future will hold for affected individuals, because even when the chromosome abnormalities are similar, the health problems can vary widely. 

Over 100 cases have been reported on ring chromosome 22. While there is no consistent clinical picture, frequent findings of ring chromosome 22 include developmental delay, moderate to severe learning difficulties or intellectual disabilities, small head, absent or delayed speech, hypotonia, unsteady manner of walking, hyperactivity, autistic behaviors, seizures, and growth delay. Some affected individuals may also have relatively mild, non-specific physical features, whereas others may have more distinctive, potentially severe physical abnormalities.[1][2][3]

Unique is a source of information and support to families and individuals affected by rare chromosome disorders. On their Web site, they have a comprehensive information pamphlet on the signs and symptoms associated with ring chromosome 22. Click on the link to view this information.

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
2-3 toe syndactyly
Webbed 2nd and 3rd toes
0004691
Autistic behavior
0000729
Azoospermia
Absent sperm in semen
0000027
Bulbous nose
0000414
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 ]

0000750
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood

[ more ]

0002376
Dolichocephaly
Long, narrow head
Tall and narrow skull

[ more ]

0000268
Epicanthus
Eye folds
Prominent eye folds

[ more ]

0000286
Full cheeks
Apple cheeks
Big cheeks
Increased size of cheeks
Large cheeks

[ more ]

0000293
Gait ataxia
Inability to coordinate movements when walking
0002066
Generalized hypotonia
Decreased muscle tone
Low muscle tone

[ more ]

0001290
Global developmental delay
0001263
Growth delay
Delayed growth
Growth deficiency
Growth failure
Growth retardation
Poor growth
Retarded growth

[ more ]

0001510
Impaired pain sensation
Decreased pain sensation
0007328
Inappropriate behavior
0000719
Large hands
large hand
0001176
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
Lymphedema
Swelling caused by excess lymph fluid under skin
0001004
Macrotia
Large ears
0000400
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference

[ more ]

0000252
Midface retrusion
Decreased size of midface
Midface deficiency
Underdevelopment of midface

[ more ]

0011800
Neurofibromas
0001067
Pointed chin
Pointy chin
Small pointed chin
Witch's chin

[ more ]

0000307
Protruding tongue
Prominent tongue
Tongue sticking out of mouth

[ more ]

0010808
Seizure
0001250
Thick eyebrow
Bushy eyebrows
Dense eyebrow
Heavy eyebrows
Prominent eyebrows
Thick eyebrows

[ more ]

0000574
Thick vermilion border
Full lips
Increased volume of lip
Plump lips
Prominent lips
Thick lips

[ more ]

0012471
Toenail dysplasia
Abnormal toenail development
0100797
Wide nasal base
Broad base of nose
Broad nasal base
Increased width of base of nose
Increased width of nasal base
Wide base of nose

[ more ]

0012810
5%-29% of people have these symptoms
Absent septum pellucidum
0001331
Agenesis of corpus callosum
0001274
Pleural effusion
Fluid around lungs
0002202

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

    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
    • Unique is a source of information and support to families and individuals affected by rare chromosome disorders. Click on the link to view information about ring chromosome 22.

      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 Ring chromosome 22. Click on the link to view a sample search on this topic.

        References

        1. Ring 22. Unique. 2006; https://www.rarechromo.org/information/Chromosome%2022/Ring%2022%20FTNW.pdf. Accessed 7/11/2011.
        2. Albert Schinzel & Walter de Gruyter . Catalogue of Unbalanced Chromosome Aberrations in Man, 2nd ed.. New York: GmbH & Co.; 2001;
        3. Chromosome 22 ring. National Organization for Rare Disorders (NORD). . 2009; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/929/viewAbstract. Accessed 7/11/2011.

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