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.
Age of Onset
Autosomal dominant ?A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease
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
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.
X-linked recessive ?Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder
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.
Other Names (AKA)
BBS; Biedl-Bardet Syndrome
Congenital and Genetic Diseases; Digestive Diseases; Endocrine Diseases;
- Progressive vision loss due to deterioration of the retina. This usually begins in mid-childhood with problems with night vision, followed by the development of blind spots in peripheral vision. Blind spots become bigger with time and eventually merge to produce tunnel vision. Most individuals also develop blurred central vision and become legally blind by adolescence or early adulthood (over 90% of cases).
- Extra finger next to the pinky (postaxial
- Kidney problems (polycystic kidneys)
- Obesity that develops around 2-3 years of age
- Abnormalities of the genitalia and infertility due to
- Learning disorders
High blood pressure
- Heart defects
- Bowel disease (Hirschsprung disease)
- Neurological problems resulting in gait and coordination impairment
- Speech and language problems
- Behavioral disorders
- Distinctive facial appearance
- Dental abnormalities
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||
|80%-99% of people have these symptoms|
Mental retardation, nonspecific
[ more ]
|Multicystic kidney dysplasia||0000003|
Having too much body fat
|Postaxial hand polydactyly||
Extra little finger
Extra pinkie finger
Extra pinky finger
[ more ]
|30%-79% of people have these symptoms|
Decreased activity of gonads
|Hypoplasia of penis||
|Hypoplasia of the ovary||
Involuntary, rapid, rhythmic eye movements
Decreased body height
[ more ]
|5%-29% of people have these symptoms|
[ more ]
|Downslanted palpebral fissures||
Downward slanting of the opening between the eyelids
Excessive hairiness over body
[ more ]
|Low-set, posteriorly rotated ears||0000368|
|Medial flaring of the eyebrow||0010747|
|Neurological speech impairment||
[ more ]
|Prominent nasal bridge||
Elevated nasal bridge
High nasal bridge
Prominent bridge of nose
Prominent nasal root
Protruding bridge of nose
Protruding nasal bridge
[ more ]
Decreased length of neck
|Skeletal muscle atrophy||
[ more ]
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.
- 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.
- While there is no therapy for the progressive vision loss, early evaluation by a specialist can help to provide vision aids and mobility training. Additionally, education of affected children should include planning for future blindness.
- Management of obesity may include education, diet, exercise, and behavioral therapies beginning at an early age. Complications of obesity such as abnormally high cholesterol and
diabetes mellitusare usually treated as they are in the general population.
- Management of intellectual disability includes early intervention, special education and speech therapy as needed. Many affected adults are able to develop independent living skills.
- Although kidney transplants have been successful, the immunosuppressants used after a transplant may contribute to obesity. Affected individuals may also need surgery for
polydactyly(extra fingers and/or toes) or genital abnormalities.
- As children approach puberty,
hormonelevels should be monitored to determine if hormone replacement therapy is necessary. Additionally, it should not be assumed that affected individuals are infertile so contraception advice should be offered.
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.
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.
- MedlinePlus Genetics contains information on Bardet-Biedl syndrome. This website is maintained by the National Library of Medicine.
- 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.
- 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) lists the subtypes and associated genes for Bardet-Biedl syndrome in a table called Phenotypic Series. Each entry in OMIM includes 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 Bardet-Biedl syndrome. Click on the link to view a sample search on this topic.
- Bardet Biedl Syndrome. National Organization for Rare Disorders. 2007; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/988/viewAbstract.
- Forsythe E, Beales PL. Bardet-Biedl Syndrome. GeneReviews. 2015; https://www.ncbi.nlm.nih.gov/books/NBK1363/.
- Weihbrecht K, Goar WA, Pak T, et al. Keeping an Eye on Bardet-Biedl Syndrome: A Comprehensive Review of the Role of Bardet-Biedl Syndrome Genes in the Eye. Med Res Arch. September, 2017; 5(9):https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5814251/.
- Bardet-Biedl syndrome. Genetics Home Reference. September 2013; https://ghr.nlm.nih.gov/condition/bardet-biedl-syndrome.
- Bardet-Biedl syndrome. Orphanet. 2008; https://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=3244.
- Waters AM & Beales PL. Bardet-Biedl Syndrome. GeneReviews. April 23, 2015; https://www.ncbi.nlm.nih.gov/books/NBK1363/.
- Aoife M Waters, Philip L Beales. Bardet-Biedl syndrome. GeneReviews. 2015; https://www.ncbi.nlm.nih.gov/books/NBK1363/.
- Hufnagel RB, Amo G, Hein ND, Hersheson J, Prasad M, Anderson Y, et al.. Neuropathy target esterase impairments cause Oliver-McFarlane and Laurence-Moon syndromes. J Med Genet. February, 2015; 52(2):85-94. https://www.ncbi.nlm.nih.gov/pubmed/25480986.