Birk-Barel syndrome

Title

Other Names:

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

Categories:

Congenital and Genetic Diseases; Nervous System Diseases

Summary 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]

Last updated: 10/15/2014

Symptoms 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.

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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

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Do you have more information about symptoms of this disease? We want to hear from you.

Last updated: 2/1/2021

Do you have updated information on this disease? We want to hear from you.

Diagnosis 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.

Find a Specialist Find a Specialist

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by the American College of Medical Genetics and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from MedlinePlus Genetics.

Organizations 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

Visit the KCNK9 Imprinting Syndrome- Birk-Barel group on Facebook.

Do you know of an organization? We want to hear from you.

Learn More 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 (GHR) contains information on Birk-Barel syndrome. This website is maintained by the National Library of Medicine.

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.

GARD Answers GARD Answers

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

Have a question? Contact a GARD Information Specialist.

References References

Birk-Barel Mental Retardation Dysmorphism Syndrome. Online Mendelian Inheritance in Man (OMIM). September 19, 2008; http://omim.org/entry/612292. Accessed 10/15/2014.
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. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495061/. Accessed 10/15/2014.

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