Bardet-Biedl syndrome
From Wikipedia, the free encyclopedia
| Bardet-Biedl syndrome Classification and external resources |
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| ICD-10 | Q87.8 |
|---|---|
| ICD-9 | 759.89 |
| OMIM | 209900 |
| DiseasesDB | 7286 |
| MeSH | D020788 |
- Laurence-Moon-Biedl syndrome and Laurence-Moon-Biedl-Bardet redirect here. See below for an explanation.
The Bardet-Biedl syndrome is a genetic disorder characterized mainly by obesity, pigmentary retinopathy, polydactyly, mental retardation, hypogonadism, and renal failure in some cases.[1]
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[edit] Eponym and classification
The syndrome is named after Georges Bardet and Arthur Biedl.[2]
Two forms have been identified:
- Bardet-Biedl syndrome 1 (BBS1) is mapped to markers on chromosome 11
- Bardet-Biedl syndrome 2 (BBS2) is mapped to markers on chromosome 16
The first known case was reported by Laurence and Moon in 1866 at the Ophthalmic Hospital in South London. Laurence-Moon-Biedl-Bardet syndrome are no longer considered as valid terms in that patients of Laurence and Moon had paraplegia but no polydactyly and obesity which are the key elements of the Bardet-Biedl the syndrome. Laurence-Moon syndrome is usually considered a separate entity. However, some recent research suggests that the two conditions may not be distinct.[3]
[edit] Major features
- Eyes: Pigmentary retinopathy, poor visual acuity, low vision, and/or blindness.
- Nose: Loss of, or reduced sense of, smell. (anosmia)
- Hand and foot: Polydactyly or syndactyly (webbing of fingers and toes).
- Cardiovascular system: Hypertrophy of interventricular septum and left ventricle and dilated cardiomyopathy.
- Gastrointestinal system: Fibrosis.
- Urogenital system: Hypogonadism, renal failure, urogenital sinuses, ectopic urethra, uterus duplex, septate vagina, and hypoplasia of the uterus, ovaries, and fallopian tubes.
- Growth and development: Mental and growth retardation.
- Behavior and performance: a wide variety of socialization and social interaction problems have been identified with BBS. Some refer to it as a kind of "mild-Autism." Many children who are later (explicitly and formally) diagnosed with the syndrome have gone through an extended period of time where school and medical professionals have struggled to find a name for the child's problems over several years.
- Heredity: The syndrome is familial and is transmitted as an autosomal recessive trait. chromosome 3 locus appears to be linked to polydactyly of all four limbs, whereas chromosome 15 is associated with early-onset morbid obesity and is mostly confined to the hands, and chromosome 16 represents the "leanest" form.
- Additional features: Obesity.
[edit] Cause
The detail biochemical mechanism that leads to BBS is still unclear. At this moment, twelve genes (BBS1 to BBS12) that are responsible for the disease when mutated, have been cloned. The gene products encoded by these BBS genes, called BBS proteins, are located in the basal body and cilia of the cell.
Using the round worm C. elegans as a model system, biologists found that BBS proteins are involved in a process called Intraflagellar transport (IFT), a bi-directional transportation activity within the cilia along the long axis of the ciliary shaft, that are essential for the formation and maintenance of cilia. Recent biochemical analysis of human BBS proteins revealed that BBS proteins are assembled into a multiple protein complex, called "BBSome". BBSome is proposed to be responsible for transporting intracellular vesicles to the base of the cilia and to play an important roles in the ciliary function. Since abnormalities of cilia are known to be related to a wide range of disease symptoms including those commonly seen in BBS patients, it is now widely accepted that mutated BBS genes affect normal cilia functions, which, in turns, cause BBS.
[edit] June 2006 Conference
- The LMBBS Association Family Meeting for non-medical-professionals was held in Houston, Texas, June 16-17, 2006.
- The conference was sponsored by a steering committee of BBS folk and parents/grandparents of children with BBS. It was directed to a lay audience.
- A primary purpose of the conference was to present the latest medical research results in an accessible fashion. This included one morning of presentations by leading BBS genetic researchers Dr. Richard Lewis (Baylor Medical Center, Houston) and Dr. Nicholas Katsanis (Johns Hopkins University, Baltimore, Maryland). Several additional doctors presented accessible information on growth and weight management; kidney issues; obesity & Syndrome X; pediatric bariatric surgery; and speech pathology & therapy.
- Location: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas.
- For additional information about the meeting, click here.
[edit] References
- ^ Beales P, Elcioglu N, Woolf A, Parker D, Flinter F (1999). "New criteria for improved diagnosis of Bardet-Biedl syndrome: results of a population survey". J. Med. Genet. 36 (6): 437-46. PMID 10874630.
- ^ synd/3745 at Who Named It
- ^ Moore S, Green J, Fan Y et al (2005). "Clinical and genetic epidemiology of Bardet-Biedl syndrome in Newfoundland: a 22-year prospective, population-based, cohort study". Am. J. Med. Genet. A 132 (4): 352-60. doi:. PMID 15637713.
[edit] External links
- Laurence Moon Bardet Biedl Society (UK-based)
- LMBBS Association (US-based; newly formed in June at the Houston 2006 BBS conference)
- The Importance of Being Cilia Accessible article at Howard Hughes Medical Institute on the importance and extensive use of cilia and basal bodies in many organ systems of human physiology. Includes multiple specific mentions of BBS.
- BBS and loss of the sense of smell at Johns Hopkins University
- Overview at United States National Library of Medicine
- Foundation Fighting Blindness
- Bardet-Biedl Syndrome Association francaise (France-based; in French language) Syndrome de Bardet-Biedl (BBS)
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