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Shoemaker A. Bardet-Biedl syndrome: A clinical overview focusing on diagnosis, outcomes and best-practice management. Diabetes Obes Metab 2024; 26 Suppl 2:25-33. [PMID: 38383825 DOI: 10.1111/dom.15494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/16/2024] [Accepted: 01/27/2024] [Indexed: 02/23/2024]
Abstract
Bardet-Biedl syndrome (BBS) is a genetic disorder characterized by early-onset obesity, polydactyly, genital and kidney anomalies, developmental delay and vision loss due to rod-cone dystrophy. BBS is an autosomal recessive disorder with >20 implicated genes. The genotype-phenotype relationship in BBS is not clear, and there may be additional modifying factors. The underlying mechanism is dysfunction of primary cilia. In BBS, receptor trafficking in and out of the cilia is compromised, affecting multiple organ systems. Along with early-onset obesity, hyperphagia is a prominent symptom and contributes significantly to clinical morbidity and caregiver burden. While there is no cure for BBS, setmelanotide is a new pharmacotherapy approved for treatment of obesity in BBS. The differential diagnosis for BBS includes other ciliopathies, such as Alstrom syndrome, and other genetic obesity syndromes, such as Prader-Willi syndrome. Careful clinical history and genetic testing can help determine the diagnosis and a multidisciplinary team is necessary to guide clinical management.
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Affiliation(s)
- Ashley Shoemaker
- Division of Pediatric Endocrinology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Adeva-Andany MM, Domínguez-Montero A, Adeva-Contreras L, Fernández-Fernández C, Carneiro-Freire N, González-Lucán M. Body Fat Distribution Contributes to Defining the Relationship between Insulin Resistance and Obesity in Human Diseases. Curr Diabetes Rev 2024; 20:e160823219824. [PMID: 37587805 DOI: 10.2174/1573399820666230816111624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/28/2023] [Accepted: 05/31/2023] [Indexed: 08/18/2023]
Abstract
The risk for metabolic and cardiovascular complications of obesity is defined by body fat distribution rather than global adiposity. Unlike subcutaneous fat, visceral fat (including hepatic steatosis) reflects insulin resistance and predicts type 2 diabetes and cardiovascular disease. In humans, available evidence indicates that the ability to store triglycerides in the subcutaneous adipose tissue reflects enhanced insulin sensitivity. Prospective studies document an association between larger subcutaneous fat mass at baseline and reduced incidence of impaired glucose tolerance. Case-control studies reveal an association between genetic predisposition to insulin resistance and a lower amount of subcutaneous adipose tissue. Human peroxisome proliferator-activated receptorgamma (PPAR-γ) promotes subcutaneous adipocyte differentiation and subcutaneous fat deposition, improving insulin resistance and reducing visceral fat. Thiazolidinediones reproduce the effects of PPAR-γ activation and therefore increase the amount of subcutaneous fat while enhancing insulin sensitivity and reducing visceral fat. Partial or virtually complete lack of adipose tissue (lipodystrophy) is associated with insulin resistance and its clinical manifestations, including essential hypertension, hypertriglyceridemia, reduced HDL-c, type 2 diabetes, cardiovascular disease, and kidney disease. Patients with Prader Willi syndrome manifest severe subcutaneous obesity without insulin resistance. The impaired ability to accumulate fat in the subcutaneous adipose tissue may be due to deficient triglyceride synthesis, inadequate formation of lipid droplets, or defective adipocyte differentiation. Lean and obese humans develop insulin resistance when the capacity to store fat in the subcutaneous adipose tissue is exhausted and deposition of triglycerides is no longer attainable at that location. Existing adipocytes become large and reflect the presence of insulin resistance.
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Affiliation(s)
- María M Adeva-Andany
- Nephrology Division, Department of Internal Medicine, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406 Ferrol, Spain
| | - Alberto Domínguez-Montero
- Nephrology Division, Department of Internal Medicine, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406 Ferrol, Spain
| | | | - Carlos Fernández-Fernández
- Nephrology Division, Department of Internal Medicine, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406 Ferrol, Spain
| | - Natalia Carneiro-Freire
- Nephrology Division, Department of Internal Medicine, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406 Ferrol, Spain
| | - Manuel González-Lucán
- Nephrology Division, Department of Internal Medicine, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406 Ferrol, Spain
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Alghaith FA, MacKay S, Wallace K, Locke J, Robitaille JM, Dyack S, Arts HH. Recurrence of a BBS1 variant in Bardet-Biedl patients from Prince Edward Island. Clin Genet 2023; 104:713-715. [PMID: 37612261 DOI: 10.1111/cge.14418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023]
Abstract
This study reports variants in BBS1 and BBS7 in patients with Bardet-Biedl syndrome from the Canadian Maritime provinces. The BBS1 variant NM_024649.5:c.1169T>G was identified as a recurrent variant in Prince Edward Island.
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Affiliation(s)
- Fahad A Alghaith
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sara MacKay
- Maritime Medical Genetics Service, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Karin Wallace
- Division of Ophthalmology, Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jeff Locke
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Johane M Robitaille
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sarah Dyack
- Maritime Medical Genetics Service, IWK Health Centre, Halifax, Nova Scotia, Canada
- Department of Pediatrics and Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Heleen H Arts
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
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Abstract
The BBSome is an octameric protein complex involved in Bardet-Biedl syndrome (BBS), a human pleiotropic, autosomal recessive condition. Patients with BBS display various clinical features including obesity, hypertension, and renal abnormalities. Association studies have also linked the BBS genes to hypertension and other cardiovascular risks in the general population. The BBSome was originally associated with the function of cilia, a highly specialized organelle that extend from the cell membrane of most vertebrate cells. However, subsequent studies have implicated the BBSome in the control of a myriad of other cellular processes not related to cilia including cell membrane localization of receptors and gene expression. The development of animal models of BBS such as mouse lines lacking various components of the BBSome and associated proteins has facilitated studying their role in the control of cardiovascular function and deciphering the pathophysiological mechanisms responsible for the cardiovascular aberrations associated with BBS. These studies revealed the importance of the neuronal, renal, vascular, and cardiac BBSome in the regulation of blood pressure, renal function, vascular reactivity, and cardiac development. The BBSome has also emerged as a critical regulator of key systems involved in cardiovascular control including the renin-angiotensin system. Better understanding of the influence of the BBSome on the molecular and physiological processes relevant to cardiovascular health and disease has the potential of identifying novel mechanisms underlying hypertension and other cardiovascular risks.
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Affiliation(s)
- Yuying Zhao
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Human Toxicology Graduate Program, University of Iowa Graduate College, Iowa City, IA, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Obesity Research and Educational Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Iowa City VA Health Care System, Iowa City, IA, USA,Corresponding author: Kamal Rahmouni, Ph.D., Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA, , Tel: 319 353 5256, Fax: 319 353 5350
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Guardiola G, Ramos F, Izquierdo N. Retinitis Pigmentosa and Polydactyly in a Patient with a Heterozygous Mutation on the BBS1 Gene. Int Med Case Rep J 2021; 14:459-463. [PMID: 34262361 PMCID: PMC8273909 DOI: 10.2147/imcrj.s321961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/28/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To report retinitis pigmentosa and a history of polydactyly in a Bardet–Biedl syndrome mutation carrier. Observations A 25-year-old male presented to the clinic complaining of poor visual acuity since childhood, night-blindness, and progressive peripheral vision loss. The patient also had a history of polydactyly in both feet. Ophthalmic evaluation was remarkable for a best-corrected visual acuity of 20/400 in both eyes. Imaging revealed a “salt-and-pepper” appearance surrounding the macula, bone-spicule retinal pigment epithelium hyperplasia, paravenous retinal pigment epithelium hyperplasia, and arteriolar attenuation. In addition, bilateral macular autofluorescence with a surrounding granular hypoautofluorescence and an additional hyperautofluorescent zone was present. Full-field ERG results showed non-recordable scotopic ERG responses and diminished photopic ERG responses OU, consistent with progressive rod-cone dystrophy. Genetic testing was positive for a pathogenic heterozygous mutation in the BBS1 gene of the variant c.1169T>G (p.Met390Arg) and several variants of uncertain significance in other genes. Conclusions and Importance Ascertainment of the inheritance patterns in BBS is an evolving discussion. Our case, a BBS carrier with retinitis pigmentosa and a history of polydactyly, could support previous research suggesting non-Mendelian genetics in this ciliopathy. Furthermore, genetic testing and analyses of additional mutations and variants of uncertain significance could potentially explain the reason for BBS-like phenotype in presumed BBS carriers.
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Affiliation(s)
| | - Fabiola Ramos
- Department of Ophthalmology, University of Puerto Rico School of Medicine, University of Puerto Rico, San Juan, PR, US
| | - Natalio Izquierdo
- Department of Surgery, University of Puerto Rico School of Medicine, University of Puerto Rico, San Juan, PR, US
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Mujahid S, Hunt KF, Cheah YS, Forsythe E, Hazlehurst JM, Sparks K, Mohammed S, Tomlinson JW, Amiel SA, Carroll PV, Beales PL, Huda MSB, McGowan BM. The Endocrine and Metabolic Characteristics of a Large Bardet-Biedl Syndrome Clinic Population. J Clin Endocrinol Metab 2018; 103:1834-1841. [PMID: 29409041 DOI: 10.1210/jc.2017-01459] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 01/26/2018] [Indexed: 01/03/2023]
Abstract
CONTEXT Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder in which previous reports have described obesity and a metabolic syndrome. OBJECTIVE We describe the endocrine and metabolic characteristics of a large BBS population compared with matched control subjects. DESIGN We performed a case-control study. SETTING This study was performed at a hospital clinic. PATIENTS Study patients had a clinical or genetic diagnosis of BBS. MAIN OUTCOME MEASUREMENTS Our study determined the prevalence of a metabolic syndrome in our cohort. RESULTS A total of 152 subjects were studied. Eighty-four (55.3%) were male. Mean (± standard deviation) age was 33.2 ± 1.0 years. Compared with age-, sex-, and body mass index-matched control subjects, fasting glucose and insulin levels were significantly higher in subjects with BBS (glucose: BBS, 5.2 ± 1.2 mmol/L vs control, 4.9 ± 0.9 mmol/L, P = 0.04; insulin: BBS, 24.2 ± 17.0 pmol/L vs control, 14.2 ± 14.8 pmol/L, P < 0.001). Serum triglycerides were significantly higher in subjects with BBS (2.0 ± 1.2 mmol/L) compared with control subjects (1.3 ± 0.8 mmol/L; P < 0.001), but total cholesterol, high-density lipoprotein, and low-density lipoprotein were similar in both groups. Systolic blood pressure was higher in the BBS group (BBS, 135 ± 18 mm Hg vs control subjects, 129 ± 16 mm Hg; P = 0.02). Alanine transaminase was raised in 34 (26.8%) subjects with BBS, compared with five (8.9%) control subjects (P = 0.01). The rate of metabolic syndrome, determined using International Diabetes Federation criteria, was significantly higher in the BBS group (54.3%) compared with control subjects (26% P < 0.001). Twenty-six (19.5%) of male subjects with BBS were hypogonadal (serum testosterone, 9.9 ± 5.3 mmol/L), but significant pituitary abnormalities were uncommon. Subclinical hypothyroidism was present in 24 of 125 (19.4%) patients with BBS, compared with 3 of 65 (4.6%) control subjects (P = 0.01). CONCLUSIONS Insulin resistance and the metabolic syndrome are increased in adult patients with BBS compared with matched control subjects. Increased subclinical hypothyroidism in the BBS cohort needs further investigation.
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Affiliation(s)
- Safa Mujahid
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Katharine F Hunt
- King's Diabetes Research Group, King's College London, London, United Kingdom
| | - Yee S Cheah
- King's Diabetes Research Group, King's College London, London, United Kingdom
| | | | - Jonathan M Hazlehurst
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- University Hospitals, Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Kathryn Sparks
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Shehla Mohammed
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- University Hospitals, Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Stephanie A Amiel
- King's Diabetes Research Group, King's College London, London, United Kingdom
| | - Paul V Carroll
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Phillip L Beales
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Mohammed S B Huda
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
- King's Diabetes Research Group, King's College London, London, United Kingdom
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Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive genetic disorder. It is characterized by heterogeneous clinical manifestations including primary features of the disease (rod-cone dystrophy, polydactyly, obesity, genital abnormalities, renal defects, and learning difficulties) and secondary BBS characteristics (developmental delay, speech deficit, brachydactyly or syndactyly, dental defects, ataxia or poor coordination, olfactory deficit, diabetes mellitus, congenital heart disease, etc.); most of these symptoms may not be present at birth but appear and progressively worsen during the first and second decades of life. At least 20 BBS genes have already been identified, and all of them are involved in primary cilia functioning. Genetic diagnosis of BBS is complicated due to lack of gene-specific disease symptoms; however, it is gradually becoming more accessible with the invention of multigene sequencing technologies. Clinical management of BBS is largely limited to a symptomatic treatment. Mouse experiments demonstrate that the most debilitating complication of BBS, blindness, can be rescued by topical gene therapy. There is a published case report describing the delay of BBS symptoms by nutritional compensation of the disease-related biochemical deficiencies. Progress in DNA testing technologies is likely to rapidly resolve all limitations in BBS diagnosis; however, much slower improvement is expected with regard to BBS treatment.
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Affiliation(s)
- Evgeny N Suspitsin
- N.N. Petrov Institute of Oncology, St. Petersburg, Russia; St. Petersburg Pediatric Medical University, St. Petersburg, Russia
| | - Evgeny N Imyanitov
- N.N. Petrov Institute of Oncology, St. Petersburg, Russia; St. Petersburg Pediatric Medical University, St. Petersburg, Russia; I.I. Mechnikov North-Western Medical University, St. Petersburg, Russia; St. Petersburg State University, St. Petersburg, Russia
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Warden G, Harnett D, Green J, Wish T, Woods MO, Green R, Dicks E, Rahman P, Zhai G, Parfrey P. A population-based study of hereditary non-polyposis colorectal cancer: evidence of pathologic and genetic heterogeneity. Clin Genet 2013; 84:522-30. [PMID: 23278430 DOI: 10.1111/cge.12080] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 12/13/2012] [Accepted: 12/13/2012] [Indexed: 01/30/2023]
Abstract
Hereditary non-polyposis colorectal cancer (HNPCC) may be the result of Lynch syndrome (LS) caused by mutations in mismatch repair (MMR) genes, a syndrome of unknown etiology called familial colorectal cancer type-X (FCCTX), or familial serrated neoplasia associated with the colorectal cancer (CRC) somatic BRAF mutation. To determine the cause of HNPCC in the founder population of the island of Newfoundland, we studied 37 families with LS and 29 families without LS who fulfilled the Amsterdam I criteria. In non-LS, four index CRCs were BRAF mutation positive, one of which was microsatellite instable. Geographic clustering of LS families caused by three different founder mutations in MSH2 was observed. Nine unique MMR mutations in four MMR genes were identified in single families distributed in different geographic isolates. The geographic distribution of non-LS was similar to LS. The coefficient of relatedness using genotype data was significantly higher for non-LS than for all CRC. Extensive genealogic investigation failed to connect non-LS families and in some clusters pathologic CRC heterogeneity was observed. We conclude that non-LS HNPCC may be a heterogeneous disorder with different pathogenic pathways, and that the geographic distribution is consistent with multiple different mutations in unknown CRC susceptibility gene(s).
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Marion V, Mockel A, De Melo C, Obringer C, Claussmann A, Simon A, Messaddeq N, Durand M, Dupuis L, Loeffler JP, King P, Mutter-Schmidt C, Petrovsky N, Stoetzel C, Dollfus H. BBS-induced ciliary defect enhances adipogenesis, causing paradoxical higher-insulin sensitivity, glucose usage, and decreased inflammatory response. Cell Metab 2012; 16:363-77. [PMID: 22958920 DOI: 10.1016/j.cmet.2012.08.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 06/13/2012] [Accepted: 08/16/2012] [Indexed: 01/11/2023]
Abstract
Studying ciliopathies, like the Bardet-Biedl syndrome (BBS), allow the identification of signaling pathways potentially involved in common diseases, sharing phenotypic features like obesity or type 2 diabetes. Given the close association between obesity and insulin resistance, obese BBS patients would be expected to be insulin resistant. Surprisingly, we found that a majority of obese BBS patients retained normal glucose tolerance and insulin sensitivity. Patient's adipose tissue biopsies revealed upregulation of adipogenic genes and decrease of inflammatory mediators. In vitro studies on human primary mesenchymal stem cells (MSCs) showed that BBS12 inactivation facilitated adipogenesis, increased insulin sensitivity, and glucose utilization. We generated a Bbs12(-/-) mouse model to assess the impact of Bbs12 inactivation on adipocyte biology. Despite increased obesity, glucose tolerance was increased with specific enhanced insulin sensitivity in the fat. This correlated with an active recruitment of MSCs resulting in adipose tissue hyperplasia and decreased in inflammation.
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Affiliation(s)
- Vincent Marion
- Laboratoire de Physiopathologie des Syndromes Rares Héréditaires, AVENIR-Inserm, EA3949, Université de Strasbourg, 11 rue Humann, 67085 Strasbourg, France.
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Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathy characterised by retinal dystrophy, obesity, post-axial polydactyly, renal dysfunction, learning difficulties and hypogonadism. Many associated minor features can be helpful in making a diagnosis and are important in the clinical management of BBS. The diagnosis is based on clinical findings and can be confirmed by sequencing of known disease-causing genes in 80% of patients. BBS genes encode proteins that localise to the cilia and basal body and are involved in cilia biogenesis and function. Mutations lead to defective cilia accounting in part for the pleiotropic effects observed in BBS. We provide an overview of BBS including the clinical findings, current understanding of cilia biology, and a practical approach to diagnosis, genetic counselling and up-to-date management.
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Affiliation(s)
- Elizabeth Forsythe
- Molecular Medicine Unit, Institute of Child Health, University College London, London, UK
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Putoux A, Attie-Bitach T, Martinovic J, Gubler MC. Phenotypic variability of Bardet-Biedl syndrome: focusing on the kidney. Pediatr Nephrol 2012; 27:7-15. [PMID: 21246219 DOI: 10.1007/s00467-010-1751-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Revised: 11/26/2010] [Accepted: 11/30/2010] [Indexed: 12/12/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a multisystemic developmental disorder diagnosed on the basis of the presence of obesity, retinal defects, polydactyly, hypogonadism, renal dysfunction, and learning disabilities. The syndrome is genetically heterogeneous with 14 BBS genes identified to date. Since the cloning of the first gene in 2000, a combination of genetic, in vitro, and in vivo studies have highlighted ciliary dysfunction as a primary cause of BBS pathology. Pleiotropy of ciliopathy phenotypes and complex genetic interactions between causal and modifying alleles of ciliary genes contribute to phenotypic variability. In particular, kidney disease in BBS is clinically heterogeneous, but is now recognized as a cardinal feature and a major cause of mortality in BBS.
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Affiliation(s)
- Audrey Putoux
- INSERM U-781, Hôpital Necker-Enfants Malades, Paris, France
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High incidence of pediatric idiopathic epilepsy is associated with familial and autosomal dominant disease in Eastern Newfoundland. Epilepsy Res 2011; 98:140-7. [PMID: 21959335 DOI: 10.1016/j.eplepsyres.2011.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 07/29/2011] [Accepted: 09/03/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE To describe the incidence and epidemiology of pediatric idiopathic epilepsy (IE) in Newfoundland and Labrador. METHODS All children in Newfoundland and Labrador aged 0-15 years with IE were ascertained through the provincial neurology clinic at the Janeway Child Health Centre. Family history, medical history and blood samples were obtained from probands and relatives. Two genes, SCN1A and KCNQ2, were screened for mutations by direct sequencing. RESULTS The mean annual incidence of IE for the population of children living in the Avalon region of Newfoundland from 2000 to 2004 was 107 per 100,000. This rate is approximately three-fold greater than rates reported in other developed countries. Of 117 families with IE eligible for study, 86 (74%) provided detailed pedigree data. Multiple different epilepsy phenotypes were identified. Fifty-five families (64%) had a positive family history. Eight of these had family histories compatible with autosomal dominant (AD) inheritance and these families lived in five different geographic isolates. DNA was obtained from 21 families (79 individuals). The two previously identified mutations in Newfoundland families with epilepsy were sequenced and excluded as pathogenic sites in all but one family which had a mutation in SCN1A. CONCLUSION The incidence of IE is high in the Avalon Peninsula of Newfoundland and the rate of familial disease is high throughout the province of Newfoundland and Labrador. The distribution of familial and AD IE in different geographic isolates, together with the clinical heterogeneity of disease suggests substantial genetic heterogeneity. It is likely that other novel mutations will be identified in this population.
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Imhoff O, Marion V, Stoetzel C, Durand M, Holder M, Sigaudy S, Sarda P, Hamel CP, Brandt C, Dollfus H, Moulin B. Bardet-Biedl syndrome: a study of the renal and cardiovascular phenotypes in a French cohort. Clin J Am Soc Nephrol 2011; 6:22-9. [PMID: 20876674 PMCID: PMC3022245 DOI: 10.2215/cjn.03320410] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 08/24/2010] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Bardet-Biedl Syndrome (BBS) is a rare autosomal recessive ciliopathy with a wide spectrum of clinical features including obesity, retinitis pigmentosa, polydactyly, mental retardation, hypogonadism, and renal abnormalities. The molecular genetic profile of BBS is currently being investigated after the recent identification of 14 BBS genes involved in primary cilia-linked disease. This study aims to characterize the renal and cardiovascular presentations and to analyze possible relationships between genotypes and clinical phenotypes. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS This clinical study was performed in a national cohort of 33 BBS patients, 22 men and 11 women, all aged >16 years (mean age 26.3 years). RESULTS Renal abnormalities, including impairment of renal function and signs of chronic interstitial nephropathy of dysplastic nature, were documented in 82% of the patients. Cardiovascular evaluations revealed that this group of young patients had significant cardiovascular risk factors. Hypertension was found in >30% of the patients and hyperlipidemia in >60%, and almost 50% had other metabolic abnormalities. Overt diabetes was present in only 6%. With regard to genotype-phenotype correlation, patients with a mutation in the BBS6, BBS10, or BBS12 gene (10 of 33 patients) had more severe renal disease. CONCLUSIONS Our study results confirm the frequent occurrence of renal involvement in patients with BBS, underscore the high risk of cardiovascular disease in these patients, and provide new information on a possible genotype-phenotype correlation.
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Affiliation(s)
| | - Vincent Marion
- Laboratoire de Physiopathologie et Épidémiologie des Syndromes Génétiques Rares, EA 3944, Avenir INSERM, Faculté de Médecine de Strasbourg, Strasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Physiopathologie et Épidémiologie des Syndromes Génétiques Rares, EA 3944, Avenir INSERM, Faculté de Médecine de Strasbourg, Strasbourg, France
| | - Myriam Durand
- Service de Génétique Médicale, Fédération de Génétique
| | - Muriel Holder
- Service de Génétique Médicale, Hôpitaux Universitaires de Lille, Lille, France
| | - Sabine Sigaudy
- Département de Génétique Médicale, Hôpital Timone Enfant, Marseille, France; and
| | | | - Christian P. Hamel
- Service d'Ophtalmologie, Hôpitaux Universitaires de Montpellier, Montpellier, France
| | - Christian Brandt
- Service de Cardiologie, and
- Centre d'Investigation et de Recherche Clinique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Hélène Dollfus
- Service de Génétique Médicale, Fédération de Génétique
- Laboratoire de Physiopathologie et Épidémiologie des Syndromes Génétiques Rares, EA 3944, Avenir INSERM, Faculté de Médecine de Strasbourg, Strasbourg, France
| | - Bruno Moulin
- Service de Néphrologie et Transplantation Rénale
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In brief. Nat Rev Nephrol 2009. [DOI: 10.1038/nrneph.2009.136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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