Related to this topic: Patient+ | Weblinks | Equipment | Books | Your Experience | Other resources | Glossaries
Print options: Printer friendly version of this leaflet (html)     Other options:  AddThis Social Bookmark Button (what's this?)

PatientPlus articles are written for doctors and so the language can be technical. However, some people find that they add depth to the articles found in the other sections of this website which are written for non-medical people.

Bardet-Biedl Syndrome

Named after Georges Louis Bardet, a French physician, born 1885 and Artur Biedl, a Hungarian pathologist and endocrinologist, born 1869.

Epidemiology

Bardet-Biedl syndrome (BBS) is a familial condition. Although it had been originally thought to be a recessive disorder, it has been demonstrated that some forms of Bardet-Biedl syndrome require recessive mutations in 1 of the 6 loci, plus an additional mutation in a second locus.1 This has been called 'triallelic inheritance,' or 'recessive inheritance with a modifier of penetrance.'
Twelve forms have been identified, with differing phenotypes:2

  • There are only subtle differences among Bardet-Biedl families with BBS1, BBS2, or BBS4 forms. The most obvious feature is that affected offspring in the BBS1 category are taller than their parents. Affected subjects in the BBS2 and BBS4 groups were significantly shorter than their parents.
  • BBS3 patients have polydactyly limited to the lower limbs, average IQ, and obesity reversible by calorie restriction and/or exercise.
  • In reported case series of BBS 5 no patients had polydactyly, but all had brachydactyly and/or syndactyly. All had severe visual impairment with retinal macular changes, and there was hypogonadism in the 2 males examined.

Laurence-Moon-Biedl syndrome and Laurence-Moon-Biedl-Bardet syndrome are no longer considered valid terms, because the patients of Laurence and Moon had paraplegia, but no polydactyly and obesity, which are the main characteristics of the Bardet-Biedl syndrome. Laurence-Moon syndrome is a separate entity.

  • Bedouins and the Arab population of Kuwait have an incidence of 1:13,500.
  • A high incidence (1:17,500) is also found in Newfoundland. 1:160,000 elsewhere.
  • Ratio Male:Female approximately 1·3:1
Clinical Features3

  • Growth and development: Mental and growth retardation
  • Behaviour and performance: Poor visual acuity and blindness
  • Eyes: Rod-cone dystrophy (sometimes called atypical retinitis pigmentosa), myopia, strabismus, and cataracts
  • Hand and foot: Polydactyly, syndactyly or brachydactyly
  • Cardiovascular system: Hypertrophy of interventricular septum and left ventricle and dilated cardiomyopathy
  • Gastrointestinal system: Hepatic fibrosis, central obesity and diabetes mellitus
  • Urogenital system: Hypogonadism, renal failure,4 urogenital sinuses, ectopic urethra, uterus duplex, septate vagina, and hypoplasia of the uterus, ovaries, and fallopian tubes.
Differential Diagnosis
  • Laurence-Moon syndrome; where affected individuals have a spastic paraparesis, but no polydactyly
  • Cohen syndrome (CS)
Management

There are no specific treatments for the characteristics associated with Bardet-Biedl syndrome.

  • As vision worsens, individuals will benefit from the use of low-vision aids and orientation as well as from mobility training.
  • To manage the complications of renal disease, every individual with the disorder should be examined by a renal physician.
Prognosis

Prognosis is very poor where renal failure occurs.

Document references
  1. Katsanis N, Beales PL, Woods MO, et al; Mutations in MKKS cause obesity, retinal dystrophy and renal malformations associated with Bardet-Biedl syndrome. Nat Genet. 2000 Sep;26(1):67-70. [abstract]
  2. OMIM; Bardet Biedl Syndrome. Online Mendelian Inheritance in Man.
  3. Beales PL, Elcioglu N, Woolf AS, et al; New criteria for improved diagnosis of Bardet-Biedl syndrome: results of a population survey. J Med Genet. 1999 Jun;36(6):437-46. [abstract]
  4. O'Dea D, Parfrey PS, Harnett JD, et al; The importance of renal impairment in the natural history of Bardet-Biedl syndrome. Am J Kidney Dis. 1996 Jun;27(6):776-83. [abstract]
Internet and further reading Acknowledgements EMIS is grateful to Dr Hayley Willacy for writing this article. The final copy has passed scrutiny by the independent Mentor GP reviewing team. ©EMIS 2008.
DocID: 1843
Document Version: 21
DocRef: bgp1347
Last Updated: 5 Mar 2007
Review Date: 4 Mar 2009








Disclaimer: Patient UK has no control of the content of the above links. Inclusion does not imply endorsement by Patient UK.

Advertise on this site



Disclaimer: Patient UK has no control of the content of the above links. Inclusion does not imply endorsement by Patient UK.

Advertise on this site

PS - Health and Poverty

Perhaps the biggest cause of ill health in the world is poverty. Help to Make Poverty History. For example, why not lend some of your money to disadvantaged communities to enable them to trade their way out of poverty through schemes such as Shared Interest.

See also MAKEPOVERTYHISTORY North East for details and links to campaigns against poverty.

^ Top of Page