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Disease Profile

Occipital horn syndrome

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

All ages

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ICD-10

E83.0

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)

OHS; Cutis laxa X-linked; Ehlers-Danlos syndrome, occipital horn type (formerly);

Categories

Congenital and Genetic Diseases; Digestive Diseases; Lung Diseases;

Summary

Occipital horn syndrome (OHS) is a genetic condition that affects the connective tissue, skeleton, and nervous system. Symptoms of OHS usually begin in early childhood. They may include wedge-shaped calcium deposits at the base of the skull (occipital horns), loose skin and joints, and dysfunction of the nerves that regulate nonvoluntary body functions (dysautonomia). Other symptoms may include bladder diverticula, coarse hair, low muscle tone, and mild intellectual disability. This condition is a milder form of Menkes disease, which affects copper levels in the body. OHS is caused by genetic changes (DNA variants) in the ATP7A gene, and it is inherited in an x-linked recessive pattern. It can be diagnosed based on the symptoms, genetic testing, and other blood tests. Treatment for OHS is based on managing the symptoms.[1][2][3][4]

Symptoms

The following list includes the most common signs and symptoms in people with occipital horn syndrome. These features may be different from person to person. Some people may have more symptoms than others and symptoms can range from mild to severe. This list does not include every symptom or feature that has been described in this condition.

Signs and symptoms may include:[1][2]

  • Wedge shaped calcifications at the base of the skull (occipital horns)
  • Loose skin and joints
  • Bladder pouches (diverticula)
  • Blood vessel abnormalities
  • Dysautonomia (chronic diarrhea, orthostatic hypotension)
  • Mild cognitive deficits
  • Decreased muscle tone (hypotonia)
  • Hair abnormalities

The symptoms of occipital horn syndrome usually appear by early childhood. Most people with OHS have normal intelligence or only mild intellectual delay. Because this condition is so rare, there is not much information about how this condition affects people as they get older. There is some evidence that serious gastrointestinal, breathing, or bleeding complications can develop by early adulthood.[2][4] 

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
Cerebral calcification
Abnormal deposits of calcium in the brain
0002514
Delayed cranial suture closure
0000270
Exostoses
Formation of new noncancerous bone on top of existing bone
0100777
Global developmental delay
0001263
Hyperextensible skin
Hyperelastic skin
Skin hyperelasticity
Stretchable skin

[ more ]

0000974
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Joint hyperflexibility
Joints move beyond expected range of motion
0005692
Large fontanelles
Wide fontanelles
0000239
Specific learning disability
0001328
30%-79% of people have these symptoms
Abnormality of the sense of smell
Abnormal sense of smell
Smell defect

[ more ]

0004408
Abnormality of the wrist
Abnormalities of the wrists
0003019
Brachydactyly
Short fingers or toes
0001156
Bruising susceptibility
Bruise easily
Easy bruisability
Easy bruising

[ more ]

0000978
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty

[ more ]

0002015
Esophagitis
Inflammation of the esophagus
0100633
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn

[ more ]

0002020
Gastroparesis
Delayed gastric emptying
0002578
Hepatitis
Liver inflammation
0012115
Hiatus hernia
Stomach hernia
0002036
High, narrow palate
Narrow, high-arched roof of mouth
Narrow, highly arched roof of mouth

[ more ]

0002705
Hypothermia
Abnormally low body temperature
0002045
Jaundice
Yellow skin
Yellowing of the skin

[ more ]

0000952
Keloids
0010562
Long philtrum
0000343
Muscular hypotonia
Low or weak muscle tone
0001252
Osteomalacia
Softening of the bones
0002749
Osteopenia
0000938
Osteoporosis
0000939
Pectus carinatum
Pigeon chest
0000768
Pectus excavatum
Funnel chest
0000767
Platyspondyly
Flattened vertebrae
0000926
Poor suck
Poor sucking
0002033
Rickets
Weak and soft bones
0002748
Short palm
0004279
Synostosis of joints
Fusion of joints
0100240
Vascular dilatation
Wider than typical opening or gap
0002617
Venous insufficiency
Poorly functioning veins
0005293
5%-29% of people have these symptoms
Abnormality of fibula morphology
Abnormality of the calf bone
0002991
Abnormality of the pubic bone
Abnormality of the pubic bones
Abnormality of the pubis

[ more ]

0003172
Absent tibia
Absent shankbone
Absent shinbone

[ more ]

0009556
Aplasia/hypoplasia of the humerus
Absent/small long bone in upper arm
Absent/underdeveloped long bone in upper arm

[ more ]

0006507
Aplastic clavicle
Absent collarbone
0006660
Avascular necrosis of the capital femoral epiphysis
0005743
Bladder diverticulum
0000015
Coarse hair
Coarse hair texture
0002208
Coxa valga
0002673
Coxa vara
0002812
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Down-sloping shoulders
Rounded shoulders
Rounded, sloping shoulders
Sloping shoulders

[ more ]

0200021
Femoral hernia
0100541
Genu valgum
Knock knees
0002857
High forehead
0000348
Hip dislocation
Dislocated hips
Dislocation of hip

[ more ]

0002827
Hip dysplasia
0001385
Humerus varus
0003874
Inguinal hernia
0000023
Kyphosis
Hunched back
Round back

[ more ]

0002808
Large iliac wings
0008818
Narrow chest
Low chest circumference
Narrow shoulders

[ more ]

Diagnosis

Occipital horn syndrome is diagnosed based on a clinical exam, the symptoms, and can be confirmed by genetic testing. Blood tests to check the level of copper and catecholamines can also be helpful.[1][3]

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.

    Treatment

    There is no specific treatment for occipital horn syndrome. Treatment is based on managing the symptoms.[1][3]

    Specialists who may be involved in the care of someone with occipital horn syndrome include: 

    • Medical geneticist
    • Urologist
    • Neurologist
    • Nutritionist

    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 Occipital horn syndrome. Click on the link to view a sample search on this topic.

        References

        1. Kaler S. ATP7A-Related Copper Transport Disorders. GeneReviews. Updated Aug. 18, 2016; https://www.ncbi.nlm.nih.gov/books/NBK1413.
        2. Beyens A, Van Meensel K, Pottie L, De Rycke R, De Bruyne M et al. Defining the Clinical, Molecular and Ultrastructural Characteristics in Occipital Horn Syndrome: Two New Cases and Review of the Literature. Genes (Basel). Jul 12, 2019; 10(7):528. https://pubmed.ncbi.nlm.nih.gov/31336972.
        3. Kodama H, Fujisawa C, Bhadhprasit W. Inherited copper transport disorders: biochemical mechanisms, diagnosis, and treatment. Curr Drug Metab. 2012; 13(3):237-250. https://pubmed.ncbi.nlm.nih.gov/21838703.
        4. Kodama H, Fujisawa C, Bhadhprasit W. Pathology, clinical features and treatments of congenital copper metabolic disorders--focus on neurologic aspects. Brain Dev. 2011; 33(3):243-251. https://pubmed.ncbi.nlm.nih.gov/21112168.
        5. Daenais SL, Adam AN, Innis JW, Glover TW. A novel frameshift mutation in exon 23 of ATP7A (MNK) results in occipital horn syndrome and not in Menkes disease. Am J Hum Genet. 2001; 69(2):420-427. https://pubmed.ncbi.nlm.nih.gov/11431706/.

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