Bardet-Biedl syndrome



What is Bardet-Biedl syndrome?

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.

How common is Bardet-Biedl syndrome?

Bardet-Biedl syndrome is a rare condition. Please discuss with your doctor for further information.


What are the symptoms of Bardet-Biedl syndrome?

The common symptoms of Bardet-Biedl syndrome are:

  • Abnormal electroretinogram
  • Intellectual disability
  • Multicystic kidney dysplasia
  • Obesity
  • Pigmentary retinopathy
  • Postaxial hand polydactyly
  • Hypertension
  • Hypogonadism
  • Hypoplasia of penis
  • Hypoplasia of the ovary
  • Nystagmus
  • Short stature
  • Aganglionic megacolon
  • Cryptorchidism
  • Downslanted palpebral fissures
  • Finger syndactyly
  • Generalized hirsutism
  • Hearing impairment
  • Hepatic fibrosis
  • Low-set, posteriorly rotated ears
  • Medial flaring of the eyebrow
  • Nephrotic syndrome
  • Neurological speech impairment
  • Prominent nasal bridge
  • Short neck
  • Skeletal muscle atrophy
  • Abnormality of the kidney
  • Abnormality of the ovary
  • Astigmatism
  • Cataract
  • Glaucoma
  • Macrocephaly
  • Micropenis
  • Myopia
  • Rod-cone dystrophy
  • Vaginal atresia
  • Asthma
  • Ataxia
  • Autosomal recessive inheritance
  • Biliary tract abnormality
  • Brachydactyly
  • Broad foot
  • Congenital primary aphakia
  • Decreased testicular size
  • Delayed speech and language development
  • Dental crowding
  • Diabetes mellitus
  • Foot polydactyly
  • Gait imbalance
  • Global developmental delay
  • High, narrow palate
  • Hirsutism
  • Hypodontia
  • Left ventricular hypertrophy
  • Nephrogenic diabetes insipidus
  • Poor coordination
  • Radial deviation of finger
  • Retinal degeneration
  • Short foot
  • Specific learning disability
  • Strabismus
  • Syndactyly

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you or your loved one has signs or symptoms listed above or has any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes Bardet-Biedl syndrome?

BBS has an autosomal recessive pattern of inheritance. 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. 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.

Risk factors

What increases my risk for Bardet-Biedl syndrome?

Please consult with your doctor for further information.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is Bardet-Biedl syndrome diagnosed?

Please consult with your doctor for further information.

How is Bardet-Biedl syndrome treated?

There is no cure for Bardet-Biedl syndrome. Treatment generally focuses on the specific signs and symptoms in each individual:

  • 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 mellitus are 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, hormone levels 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.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Bardet-Biedl syndrome?

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: January 25, 2018 | Last Modified: January 26, 2018