Bardet-Biedl syndrome 2 (BBS2), one of the numerous forms of Bardet-Biedl syndrome (BBS), is a genetic disease that is inherited via an autosomal recessive pattern. It is characterized by the disruption of ciliary function and affects numerous organ systems in the body. It commonly causes renal, reproductive and ocular malformations, as well as obesity. BBS2 may also lead to intellectual impairment.
Bardet-Biedl syndrome 2 (BBS2), a variant of Bardet-Biedl syndrome (BBS), is a genetic condition that causes many different clinical symptoms. BBS is a ciliopathy disorder with several sub-types that result from different genetic mutations in at least 19 proteins, and displays a wide range of clinical features . The pathogenesis of BBS stems from defective or limited functioning of cilia, due to deficiencies of the mutant proteins. This affects any organ in which cilia are found, such as the eyes and kidneys, in addition to other systems.
Features of BBS develop over time, and a few may be apparent in early childhood. Major features of the condition are retinal degeneration, obesity, polydactyly, hypogonadism and underdeveloped genitalia, intellectual impairment, and renal involvement . If four of the major signs are present, then BBS can be diagnosed. It can also be diagnosed with three of the above features being present, in addition to at least two minor features . The latter may include pigmentary retinopathy (retinitis pigmentosa), polycystic kidney disease, cardiovascular anomalies, aganglionic megacolon, diabetes, and hypertension . Polydactyly may be the only obvious feature of BBS2 at birth.
Visual problems, in both acuity and color perception, may progress to total blindness. This is usually precipitated by retinitis pigmentosa. Affected individuals often become blind during childhood or adolescence. They may also experience delayed puberty and atresia of certain reproductive structures.
Children suffering from BBS may display behavioral abnormalities, and psychiatric illness such as autism. They may also experience developmental difficulties, exemplified by speech impairment and ataxia.
Entire Body System
Recurrent Urinary Tract Infection
urinary tract infections (30% of patients) Polydactyly of hands and/or feet (major) Brachydactyly of hands Speech delays Ataxia Developmental delay Learning disabilities (major) Diabetes mellitus (15-45% of patients) A clinical diagnosis is made with [en.wikibooks.org]
It is not possible to cure this condition, but regular follow-up for symptoms can improve quality of life. [ edit ] Guilt, fear, anger, anxiety, sadness, desperation, and depression are common feelings associated with this diagnosis. [en.wikibooks.org]
Recherche Public-Santé, Luxembourg, Luxembourg Jean Muller Unité de Génétique Médicale, Université Saint Joseph Faculté de Médecine, Beirut, Lebanon Sandra Corbani, Nadine Jalkh, Nabiha Salem, Eliane Chouery & André Mégarbané Service de Génétique, CHU, Angers [nature.com]
Clinical differential diagnoses of an obese child with psychomotor retardation and without polydactyly involve a wide range of possibilities, until visual impairment appears. 3 GENETICS OF THE BARDET-BIEDL SYNDROME There are at least 16 genes related [revistanefrologia.com]
Diagnosis of BBS is made by evaluation of the presenting symptoms, and molecular genetic testing . Prenatal testing and diagnosis is possible. Genotyping may be necessary to distinguish BBS from other hereditary conditions with similar presentation.
Further tests and examinations should be conducted, as these assist physicians in gauging the extent of the illness, and thus management objectives. These procedures include:
- Ophthalmological exam
- Examination of the reproductive organs
- Determination of body mass index (BMI) and dietary needs
- Cardiovascular evaluation, including blood pressure readings and echocardiogram (ECG)
- Assessment of developmental milestones
It has been suggested in the literature that diagnosis of BBS can be made if a patient presents with at least four primary features, or a combination of three of the primary as well as two secondary features  .
"We are therefore very excited about the setmelanotide study as a potential treatment for this condition." This initial study is an open-label, Phase 2 clinical trial of setmelanotide for the treatment of BBS obesity. [prnewswire.com]
“We are therefore very excited about the setmelanotide study as a potential treatment for this condition.” This initial study is an open-label, Phase 2 clinical trial of setmelanotide for the treatment of BBS obesity. [rhythmtx.com]
Treatments for the Two Conditions Treatment of BBS is focused on treating the symptoms of the disorder, such as vision correction or kidney transplants. [verywellhealth.com]
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. [rarediseases.info.nih.gov]
Glomerular disease is less common and includes focal segmental glomerulosclerosis and glomerular basement membrane detachment, although renal biopsy is rarely performed. 5 TREATMENT There is no treatment for loss of vision, but special education and future [revistanefrologia.com]
Prognosis For those with Laurence-Moon syndrome, life expectancy is usually shorter than other people. The most common cause of death is linked to renal or kidney issues. [verywellhealth.com]
Prognosis [ 2 ] Prognosis is very poor where renal failure occurs. Prevention [ 4 ] Genetic counselling and pre-conception genotyping of family members may be worthwhile if the genetic mutation has been identified in a family member. [patient.info]
The study showed that the patients had an early onset of night blindness and a poor visual prognosis. No rod ERG-responses to dim blue light were found, even in the youngest-3 years old. [lup.lub.lu.se]
(Outcomes/Resolutions) The prognosis of Bardet-Biedl Syndrome is generally guarded. [dovemed.com]
First, the syndrome has got grave prognosis and second, patient seek first consultation in these specialties, by whom they should be guided to appropriate super specialties. [cjhr.org]
Jump to navigation Jump to search Bardet-Biedl Syndrome Genetic Etiology [ edit ] Mode of inheritance: Autosomal Recessive. [en.wikibooks.org]
The etiology is still unknown, but it is described in the literature as 35% to 48% of parental consanguinity in patients with this syndrome. [dentalnews.com]
On the basis of electroencephalography, disorders with epileptic etiology were ruled out. Ophthalmological tests showed bilateral hyperopic astigmatism. [omicsonline.org]
(Etiology) Bardet-Biedl Syndrome is generally inherited as an autosomal recessive disorder. At least 12 different genes, collectively termed as the BBS genes, are involved in the development of this disorder, in a majority of cases. [dovemed.com]
[…] frequently associated abnormalities are high blood pressure and diabetes mellitus. 1,2 Adult patients consult nephrologists due to high blood pressure, abnormal renal imaging tests or kidney failure, which is the greatest cause of morbidity and mortality. 1 EPIDEMIOLOGY [revistanefrologia.com]
"Clinical and genetic epidemiology of Bardet–Biedl syndrome in Newfoundland: a 22-year prospective, population-based, cohort study". Am. J. Med. Genet. 132 (4): 352–60. doi : 10.1002/ajmg.a.30406. PMC 3295827. PMID 15637713. [en.wikipedia.org]
Bardet-Biedl syndrome epidemiology This is a rare condition and is seen in 1 in 140,000 to 1 in 160,000 newborns in most of North America and Europe. [news-medical.net]
Clinical and genetic epidemiology of Bardet-Biedl syndrome in Newfoundland: a 22-year prospective, population-based, cohort study. 106) Characterized as cerebello-oculo-renal syndromes, different types of Senior-Locken syndrome (SLSN), Joubert syndrome [medical-dictionary.thefreedictionary.com]
Relevant External Links for BBS2 Genetic Association Database (GAD) BBS2 Human Genome Epidemiology (HuGE) Navigator BBS2 Atlas of Genetics and Cytogenetics in Oncology and Haematology: BBS2 No data available for Genatlas for BBS2 Gene Positional cloning [genecards.org]
Other known ciliopathies include primary ciliary dyskinesia, polycystic kidney and liver disease, nephronophthisis, Alström syndrome, Meckel–Gruber syndrome and some forms of retinal degeneration.  Pathophysiology [ edit ] The detailed biochemical [en.wikipedia.org]
Further Reading Bardet-Biedl Syndrome Symptoms Bardet-Biedl Syndrome Pathophysiology [news-medical.net]
More than 2,000 disease genes have been identified in the last 20 years, providing important new insight into the pathophysiology of diseases in every field of medicine. [books.google.es]
The underlying pathophysiology involves a complex interaction between genetic factors and ciliary dysfunction. [patient.info]
Bardet-Biedl syndrome: Genetics, molecular pathophysiology, and disease management. Indian J Ophthalmol. 2016;64(9): 620-627. Hufnagel RB, Arno G, Hein ND, et al. [rarediseases.org]
Box 317 Watertown MA 02472 6179727441 8005626265 e-mail: [email protected] Home Page:  Prevent Blindness America 500 East Remington Road Schaumberg IL 60173 8478432020 8003312020 e-mail: [email protected] Home Page:  Vision Community [en.wikibooks.org]
TSL:3 BBS2-205 ENST00000562012.1 865 119aa ENSP00000455651 - H3BQ79 - 5' truncation in transcript evidence prevents annotation of the start of the CDS. [asia.ensembl.org]
[…] take apart for added convenience when packing and cleaning Independent on/off switches Tanks separately controlled On/off switch Easy operation Adjustable thermostats Manage the temperature separately in each tank Self-reversing motor Smart technology prevents [summitappliance.com]
Bardet-Biedl Syndrome Prevention There is no prevention for BBS as such. However, genetic counseling and preconception genotyping of family members can be effective in averting this disease. [primehealthchannel.com]
- Marion V, Schlicht D, Mockel A, et al. Bardet-Biedl syndrome highlights the major role of the primary cilium in efficient water reabsorption. Kidney Int. 2011;79(9):1013-1025.
- Khan SA, Muhammad N, Khan MA, Kamal A, Rehman ZU, Khan S. Genetics of Human Bardet-Biedl Syndrome, an Update. Clin Genet. 2016;90(1):3-15.
- Madireddi J, Acharya V, Suryanarayana J, Hande HM, Shetty R. Bardet-Biedl syndrome: multiple fingers with multiple defects! BMJ Case Rep. 2015; 2015: bcr2015211776.
- M'hamdi O, Ouertani I, Chaabouni-Bouhamed H. Update on the genetics of bardet-biedl syndrome. Mol Syndromol. 2014;5(2):51–56.
- Redin C, Le Gras S, Mhamdi O, et al. Targeted high-throughput sequencing for diagnosis of genetically heterogeneous diseases: efficient mutation detection in Bardet-Biedl and Alstrom syndromes. J Med Genet. 2012;49(8):502-512.
- Beales PL, Katsanis N, Lewis RA, et al. Genetic and mutational analyses of a large multiethnic Bardet-Biedl cohort reveal a minor involvement of BBS6 and delineate the critical intervals of other loci. Am J Hum Genet. 2001;68:606–616.
- Beales PL, Elcioglu N, Woolf AS, Parker D, Flinter FA. New criteria for improved diagnosis of Bardet-Biedl syndrome: results of a population survey. J Med Genet. 1999;36(6):437-446.