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Disease Profile

Birk-Barel 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

Infancy

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ICD-10

Q87.8

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.

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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)

Intellectual disability-hypotonia-facial dysmorphism syndrome; KCNK9 imprinting syndrome

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

Birk-Barel syndrome is an inherited condition characterized by intellectual disability, hypotonia, hyperactivity, and unusual facial features. The condition is caused by mutations in the KCNK9 gene on chromosome 8. This condition demonstrates dominant inheritance with paternal imprinting, which means that a mutation in the maternal gene will result in disease, but a mutation in the paternal gene will have no effect (imprinted with paternal silencing).[1][2]

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
Broad nasal tip
Broad tip of nose
Broad, upturned nose
Increased breadth of nasal tip
Increased breadth of tip of nose
Increased width of nasal tip
Increased width of tip of nose
Nasal tip, broad
Nasal tip, wide
Wide tip of nose

[ more ]

0000455
Broad philtrum
0000289
Dolichocephaly
Long, narrow head
Tall and narrow skull

[ more ]

0000268
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty

[ more ]

0002015
Dysphonia
Inability to produce voice sounds
0001618
Fatiguable weakness of proximal limb muscles
0030200
Generalized hypotonia
Decreased muscle tone
Low muscle tone

[ more ]

0001290
Global developmental delay
0001263
High, narrow palate
Narrow, high-arched roof of mouth
Narrow, highly arched roof of mouth

[ more ]

0002705
Highly arched eyebrow
Arched eyebrows
Broad, arched eyebrows
High, rounded eyebrows
High-arched eyebrows
Thick, flared eyebrows

[ more ]

0002553
Hyperactivity
More active than typical
0000752
Hypomimic face
Dull facial expression
0000338
Incisor macrodontia
Increased width of incisor
0011081
Micrognathia
Little lower jaw
Small jaw
Small lower jaw

[ more ]

0000347
Narrow forehead
Decreased width of the forehead
0000341
Narrow nasal bridge
Narrow bridge of nose
Nasal Bridge, Narrow
Nasal bridge, thin

[ more ]

0000446
Nasogastric tube feeding
0040288
Neonatal hypotonia
Low muscle tone, in neonatal onset
0001319
Open mouth
Gaped jawed appearance
Gaped mouthed appearance
Slack jawed appearance

[ more ]

0000194
Protruding ear
Prominent ear
Prominent ears

[ more ]

0000411
Sacral dimple
Spinal dimple
0000960
Short philtrum
0000322
Tented upper lip vermilion
0010804
Thick vermilion border
Full lips
Increased volume of lip
Plump lips
Prominent lips
Thick lips

[ more ]

0012471
5%-29% of people have these symptoms
Areflexia
Absent tendon reflexes
0001284
Congenital finger flexion contractures
0005879
Contractures involving the joints of the feet
Contractures of the foot joints
0008366
Limited elbow flexion/extension
0005060
Motor axonal neuropathy
0007002
Spinal muscular atrophy
Spinal muscle degeneration
Spinal muscle wasting

[ more ]

0007269
Tongue fasciculations
Tongue twitching
Twitching of the tongue

[ more ]

0001308
1%-4% of people have these symptoms
Bifid uvula
0000193
Feeding difficulties in infancy
0008872
High palate
Elevated palate
Increased palatal height

[ more ]

0000218
Long eyelashes
Increased length of eyelashes
Unusually long eyelashes

[ more ]

0000527
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
Microretrognathia
Small retruded chin
0000308
Reduced subcutaneous adipose tissue
Reduced fat tissue below the skin
0003758
Single transverse palmar crease
0000954
Submucous cleft soft palate
0011819
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Muscular hypotonia
Low or weak muscle tone
0001252

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.

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.

Social Networking Websites

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 Birk-Barel syndrome. Click on the link to view a sample search on this topic.

References

  1. Birk-Barel Mental Retardation Dysmorphism Syndrome. Online Mendelian Inheritance in Man (OMIM). September 19, 2008; https://omim.org/entry/612292. Accessed 10/15/2014.
  2. Barel O, Shalev SA, Ofir R, Cohen A, Zlotogora J, Shorer Z, Mazor G, Finer G, Khateeb S, Zilberberg N, Birk OS. Maternally inherited Birk Barel mental retardation dysmorphism syndrome caused by a mutation in the genomically imprinted potassium channel KCNK9. Am J Hum Genet. Aug 8, 2008; 83(2):193-199. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495061/. Accessed 10/15/2014.