National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Bardet-Biedl syndrome 1

Bardet-Biedl syndrome (BBS) is an inherited condition that affects many parts of the body. People with this syndrome have progressive visual impairment due to cone-rod dystrophy; extra fingers or toes (polydactyly); truncal obesity; decreased function of the male gonads (hypogonadism); kidney abnormalities; and learning difficulties.[1] Mutations in many genes are known to cause Bardet-Biedl syndrome and inheritance is usually autosomal recessive.[2][3] Treatment depends on the symptoms present in each person.
Last updated: 8/27/2018

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
80%-99% of people have these symptoms
Abnormal electroretinogram 0000512
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Multicystic kidney dysplasia 0000003
Obesity
Having too much body fat
0001513
Pigmentary retinopathy 0000580
Postaxial hand polydactyly
Extra little finger
Extra pinkie finger
Extra pinky finger
[ more ] 		0001162
30%-79% of people have these symptoms
Hypertension 0000822
Hypogonadism
Decreased activity of gonads
0000135
Hypoplasia of penis
Underdeveloped penis
0008736
Hypoplasia of the ovary
Underdeveloped ovary
0008724
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Short stature
Decreased body height
Small stature
[ more ] 		0004322
5%-29% of people have these symptoms
Aganglionic megacolon
Enlarged colon lacking nerve cells
0002251
Cryptorchidism
Undescended testes
Undescended testis
[ more ] 		0000028
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Finger syndactyly 0006101
Generalized hirsutism
Excessive hairiness over body
0002230
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Hepatic fibrosis 0001395
Low-set, posteriorly rotated ears 0000368
Medial flaring of the eyebrow 0010747
Nephrotic syndrome 0000100
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment
[ more ] 		0002167
Prominent nasal bridge
Elevated nasal bridge
High nasal bridge
Prominent bridge of nose
Prominent nasal root
Protruding bridge of nose
Protruding nasal bridge
[ more ] 		0000426
Short neck
Decreased length of neck
0000470
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting
[ more ] 		0003202
Percent of people who have these symptoms is not available through HPO
Abnormality of the kidney
Abnormal kidney
0000077
Abnormality of the ovary
Abnormality of the ovaries
0000137
Allergy 0012393
Asthma 0002099
Astigmatism
Abnormal curving of the cornea or lens of the eye
0000483
Ataxia 0001251
Autosomal recessive inheritance 0000007
Biliary tract abnormality 0001080
Brachydactyly
Short fingers or toes
0001156
Broad foot
Broad feet
Wide foot
[ more ] 		0001769
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Decreased testicular size
Small testes
Small testis
[ more ] 		0008734
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
Dental crowding
Crowded teeth
Dental overcrowding
Overcrowding of teeth
[ more ] 		0000678
Diabetes mellitus 0000819
Foot polydactyly
Duplication of bones of the toes
0001829
Gait imbalance
Abnormality of balance
Abnormality of equilibrium
Imbalanced walk
[ more ] 		0002141
Glaucoma 0000501
Global developmental delay 0001263
High palate
Elevated palate
Increased palatal height
[ more ] 		0000218
High, narrow palate
Narrow, high-arched roof of mouth
Narrow, highly arched roof of mouth
[ more ] 		0002705
Hirsutism
Excessive hairiness
0001007
Hypodontia
Failure of development of between one and six teeth
0000668
Left ventricular hypertrophy 0001712
Macrocephaly
Increased size of skull
Large head
Large head circumference
[ more ] 		0000256
Micropenis
Short penis
Small penis
[ more ] 		0000054
Myopia
Close sighted
Near sighted
Near sightedness
Nearsightedness
[ more ] 		0000545
Nephrogenic diabetes insipidus 0009806
Poor coordination 0002370
Radial deviation of finger 0009466
Retinal degeneration
Retina degeneration
0000546
Retinal dystrophy
Breakdown of light-sensitive cells in back of eye
0000556
Rod-cone dystrophy 0000510
Short foot
Short feet
Small feet
[ more ] 		0001773
Specific learning disability 0001328
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ] 		0000486
Syndactyly
Webbed fingers or toes
0001159
Vaginal atresia
Abnormally closed or absent vagina
0000148
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Last updated: 7/1/2020
BBS has an autosomal recessive pattern of inheritance.[2] This means that to have the syndrome, a person must have a mutation in both copies of the responsible gene in each cell. People with BBS inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a:
  • 25% chance to be affected
  • 50% chance to be an unaffected carrier like each parent
  • 25% chance to be unaffected and not a carrier
Some cases of BBS (fewer than 10%) appear to require the presence of at least three mutations for a person to have features of the condition. This is known as triallelic inheritance.[2] In these cases, in addition to inheriting a mutation in the same gene from each parent, a child also needs to have at least one more mutation in another gene to be affected.
Last updated: 9/18/2017

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.

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

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Bardet-Biedl syndrome 1. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with Bardet-Biedl syndrome 1. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for Bardet-Biedl syndrome 1:
    The Clinical Registry Investigating Bardet-Biedl Syndrome (CRIBBS)
     

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

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 Bardet-Biedl syndrome 1. 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.

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 Bardet-Biedl syndrome 1. Click on the link to view a sample search on this topic.

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.

  1. Bardet Biedl Syndrome. National Organization for Rare Disorders. 2007; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/988/viewAbstract.
  2. Forsythe E, Beales PL. Bardet-Biedl Syndrome. GeneReviews. 2015; http://www.ncbi.nlm.nih.gov/books/NBK1363/.
  3. 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/.
  4. 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.