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Fitch AK, Malhotra S, Conroy R. Differentiating monogenic and syndromic obesities from polygenic obesity: Assessment, diagnosis, and management. Obes Pillars 2024; 11:100110. [PMID: 38766314 PMCID: PMC11101890 DOI: 10.1016/j.obpill.2024.100110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 05/22/2024]
Abstract
Background Obesity is a multifactorial neurohormonal disease that results from dysfunction within energy regulation pathways and is associated with increased morbidity, mortality, and reduced quality of life. The most common form is polygenic obesity, which results from interactions between multiple gene variants and environmental factors. Highly penetrant monogenic and syndromic obesities result from rare genetic variants with minimal environmental influence and can be differentiated from polygenic obesity depending on key symptoms, including hyperphagia; early-onset, severe obesity; and suboptimal responses to nontargeted therapies. Timely diagnosis of monogenic or syndromic obesity is critical to inform management strategies and reduce disease burden. We outline the physiology of weight regulation, role of genetics in obesity, and differentiating characteristics between polygenic and rare genetic obesity to facilitate diagnosis and transition toward targeted therapies. Methods In this narrative review, we focused on case reports, case studies, and natural history studies of patients with monogenic and syndromic obesities and clinical trials examining the efficacy, safety, and quality of life impact of nontargeted and targeted therapies in these populations. We also provide comprehensive algorithms for diagnosis of patients with suspected rare genetic causes of obesity. Results Patients with monogenic and syndromic obesities commonly present with hyperphagia (ie, pathologic, insatiable hunger) and early-onset, severe obesity, and the presence of hallmark characteristics can inform genetic testing and diagnostic approach. Following diagnosis, specialized care teams can address complex symptoms, and hyperphagia is managed behaviorally. Various pharmacotherapies show promise in these patient populations, including setmelanotide and glucagon-like peptide-1 receptor agonists. Conclusion Understanding the pathophysiology and differentiating characteristics of monogenic and syndromic obesities can facilitate diagnosis and management and has led to development of targeted pharmacotherapies with demonstrated efficacy for reducing body weight and hunger in the affected populations.
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Affiliation(s)
| | - Sonali Malhotra
- Harvard Medical School, Boston, MA, USA
- Rhythm Pharmaceuticals, Inc., Boston, MA, USA
- Massachussetts General Hospital, Boston, MA, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Tomlinson JW. Bardet-Biedl syndrome: A focus on genetics, mechanisms and metabolic dysfunction. Diabetes Obes Metab 2024; 26 Suppl 2:13-24. [PMID: 38302651 DOI: 10.1111/dom.15480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/18/2024] [Accepted: 01/18/2024] [Indexed: 02/03/2024]
Abstract
Bardet-Biedl syndrome (BBS) is a rare, monogenic, multisystem disorder characterized by retinal dystrophy, renal abnormalities, polydactyly, learning disabilities, as well as metabolic dysfunction, including obesity and an increased risk of type 2 diabetes. It is a primary ciliopathy, and causative mutations in more than 25 different genes have been described. Multiple cellular mechanisms contribute to the development of the metabolic phenotype associated with BBS, including hyperphagia as a consequence of altered hypothalamic appetite signalling as well as alterations in adipocyte biology promoting adipocyte proliferation and adipogenesis. Within this review, we describe in detail the metabolic phenotype associated with BBS and discuss the mechanisms that drive its evolution. In addition, we review current approaches to the metabolic management of patients with BBS, including the use of weight loss medications and bariatric surgery. Finally, we evaluate the potential of targeting hypothalamic appetite signalling to limit hyperphagia and induce clinically significant weight loss.
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Affiliation(s)
- Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
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Melendez-Montañez JM, De Jesus-Rojas W. The Tip of the Iceberg: Genotype of Puerto Rican Pediatric Obesity. Genes (Basel) 2024; 15:394. [PMID: 38674329 PMCID: PMC11049160 DOI: 10.3390/genes15040394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 03/18/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024] Open
Abstract
Childhood obesity is a significant public health concern, particularly among Hispanic populations. This study aimed to elucidate the genetic predisposition to obesity in Puerto Rican children of Hispanic descent, addressing a notable gap in existing research. A cohort of 103 children with obesity and hyperphagia underwent genetic screening for rare obesity-related variants. Clinical assessments and family history evaluations were conducted to characterize the demographic and clinical characteristics of the cohort. Genetic testing revealed a high prevalence of variants, with 73% of subjects having at least one reported variant. Pathogenic variants, predominantly associated with obesity-related ciliopathies, were identified in 7% of cases. Additionally, 90% of cases had variants of uncertain significance, highlighting the complexity of genetic contributions to obesity. This study emphasizes the critical need for further investigation into the genetic foundations of obesity, particularly within Hispanic communities. The findings emphasize the importance of early medical evaluation, vigilant monitoring for hyperphagia onset, and targeted interventions tailored to the unique genetic landscape of Puerto Rican children. This research provides a foundational framework for future studies to mitigate the impact of genetic obesity within this population.
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Affiliation(s)
| | - Wilfredo De Jesus-Rojas
- Department of Pediatrics and Basic Science, Ponce Health Sciences University, Ponce, PR 00716, USA;
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Cetiner M, Bergmann C, Bettendorf M, Faust J, Gäckler A, Gillissen B, Hansen M, Kerber M, Klaus G, König J, Kühlewein L, Oh J, Richter-Unruh A, von Schnurbein J, Wabitsch M, Weihrauch-Blüher S, Pape L. [Improved Care and Treatment Options for Patients with Hyperphagia-Associated Obesity in Bardet-Biedl Syndrome]. Klin Padiatr 2024. [PMID: 38458231 DOI: 10.1055/a-2251-5382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2024]
Abstract
Bardet-Biedl syndrome (BBS) is a rare, autosomal recessive multisystem disease. The pathophysiological origin is a dysfunction of the primary cilium. Clinical symptoms are heterogeneous and variable: retinal dystrophy, obesity, polydactyly, kidney abnormalities, hypogenitalism and developmental delays are the most common features. By the approval of the melanocortin 4 receptor agonist setmelanotide, a drug therapy for BBS-associated hyperphagia and obesity can be offered for the first time. Hyperphagia and severe obesity represent a considerable burden and are associated with comorbidity and increased mortality risk. Due to the limited experience with setmelanotide in BBS, a viable comprehensive therapy concept is to be presented. Therapy decision and management should be conducted in expert centers. For best therapeutic effects with setmelanotide adequate information of the patient about the modalities of the therapy (daily subcutaneous injection) and possible adverse drug events are necessary. Furthermore, the involvement of psychologists, nutritionists and nursing services (support for the application) should be considered together with the patient. The assessment of therapy response should be carried out with suitable outcome measurements and centrally reported to an adequate register.
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Affiliation(s)
- Metin Cetiner
- Department of Pediatrics II, University Hospital Essen, Essen, Germany
| | - Carsten Bergmann
- Human genetic diagnostics, Medical Genetics Mainz, Mainz, Germany
| | - Markus Bettendorf
- Pediatric Endocrinology and Diabetes, Heidelberg University Hospital Department of General Pediatrics Pediatric Neurology Metabolic Diseases Gastroenterology and Nephrology, Heidelberg, Germany
| | - Johanna Faust
- Psychiatry and psychotherapy, Max-Planck-Institute for Psychiatry, München, Germany
| | - Anja Gäckler
- Department of Nephrology, University Hospital Essen, Essen, Germany
| | - Bernarda Gillissen
- Bardet Biedl syndrome Working Group, PRO RETINA Deutschland e V, Bonn, Germany
| | - Matthias Hansen
- KFH Kidney Center for Children and Adolescents, Clementine Children's Hospital - Dr Christ'sche Foundation, Frankfurt am Main, Germany
| | - Maximilian Kerber
- Bardet Biedl syndrome Working Group, PRO RETINA Deutschland e V, Bonn, Germany
| | - Günter Klaus
- KFH Kidney Center for Children and Adolescents, University Hospitals Giessen and Marburg Campus Giessen, Marburg, Germany
| | - Jens König
- Department of General Pediatrics, University Hospital Münster, Münster, Germany
| | - Laura Kühlewein
- Department of Ophthalmology, University Hospital Tübingen Clinic of Ophthalmology, Tübingen, Germany
| | - Jun Oh
- Pediatric Nephrology, University Medical Center Hamburg-Eppendorf Department of Pediatrics, Hamburg, Germany
| | - Annette Richter-Unruh
- Department of Pediatric Endocrinology and Diabetology, University Hospital of the Ruhr University Bochum, Bochum, Germany
| | - Julia von Schnurbein
- Department of Pediatrics and Adolescent Medicine, Ulm University Hospital, Ulm, Germany
| | - Martin Wabitsch
- Department of Pediatrics and Adolescent Medicine, Ulm University Hospital, Ulm, Germany
| | | | - Lars Pape
- Department of Pediatrics II, University Hospital Essen, Essen, Germany
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Li MH, Chen IC, Yang HW, Yen HC, Huang YC, Hsu CC, Chen YM, Ke YY. The characterization and comorbidities of heterozygous Bardet-Biedl syndrome carriers. Int J Med Sci 2024; 21:784-794. [PMID: 38617006 PMCID: PMC11008491 DOI: 10.7150/ijms.92766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/10/2024] [Indexed: 04/16/2024] Open
Abstract
Introduction: Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder with clinical features of retinal dystrophy, obesity, postaxial polydactyly, renal anomalies, learning disabilities, hypogonadism, and genitourinary abnormalities. Nevertheless, previous studies on the phenotypic traits of BBS heterozygous carriers have generated inconclusive results. The aim of our study was to investigate the impact of BBS heterozygosity on carriers when compared to non-carriers within the Taiwanese population. Materials and Methods: This study follows a hospital-based case-control design. We employed the Taiwan Biobank version 2 (TWBv2) array to identify three specific loci associated with BBS (rs773862084, rs567573386, and rs199910690). In total, 716 patients were included in the case group, and they were compared to a control group of 2,864 patients who lacked BBS alleles. The control group was selected through gender and age matching at a ratio of 1:4. The association between BBS-related loci and comorbidity was assessed using logistic regression models. Results: We found that BBS heterozygous carriers exhibited a significant association with elevated BMI levels, especially the variant rs199910690 in MKS1 (p=0.0037). The prevalence of comorbidities in the carriers' group was not higher than that in the non-carriers' group. Besides, the average values of the biochemistry data showed no significant differences, except for creatinine level. Furthermore, we conducted a BMI-based analysis to identify specific risk factors for chronic kidney disease (CKD). Our findings revealed that individuals carrying the CA/AA genotype of the BBS2 rs773862084 variant or the CT/TT genotype of the MKS1 rs199910690 variant showed a reduced risk of developing CKD, irrespective of their BMI levels. When stratified by BMI level, obese males with the MKS1 rs199910690 variant and obese females with the BBS2 rs773862084 variant exhibited a negative association with CKD development. Conclusion: We found that aside from the association with overweight and obesity, heterozygous BBS mutations did not appear to increase the predisposition of individuals to comorbidities and metabolic diseases. To gain a more comprehensive understanding of the genetic susceptibility associated with Bardet-Biedl Syndrome (BBS), further research is warranted.
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Affiliation(s)
- Meng-Hua Li
- Division of Pediatric Genetics and Metabolism, Children's Medical Center, Taichung Veterans General Hospital, Taichung, Taiwan
| | - I-Chieh Chen
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Hui-Wen Yang
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Hsin-Chien Yen
- Division of Pediatric Genetics and Metabolism, Children's Medical Center, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Yung-Chieh Huang
- Division of Nephrology, Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Chia-Chi Hsu
- Division of Pediatric Genetics and Metabolism, Children's Medical Center, Taichung Veterans General Hospital, Taichung, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Ming Chen
- Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Division of Allergy, Immunology, and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
- Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taiwan
| | - Yu-Yuan Ke
- Division of Pediatric Genetics and Metabolism, Children's Medical Center, Taichung Veterans General Hospital, Taichung, Taiwan
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Shikwambana MM, Fourie JV. Supporting a Tsonga learner living with Bardet-Biedl syndrome, a rare complex disability. Afr J Disabil 2023; 12:1181. [PMID: 38204908 PMCID: PMC10777427 DOI: 10.4102/ajod.v12i0.1181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/30/2023] [Indexed: 01/12/2024] Open
Abstract
Background Bardet-Biedl syndrome (BBS) is a rare, systemic, hereditary disorder characterised by obesity, polydactyly, visual and auditory impairment, and cognitive disability. Providing quality education in appropriate schools for children who present with such complex chronic conditions is challenging. Objectives This study explored the dimensions of psycho-educational support needs for a child with BBS in South Africa to contribute to the improvement of early detection and holistic interventions. Method A descriptive in-depth qualitative case study of Gezani, an adolescent Tsonga boy diagnosed with BBS, was undertaken. Semi-structured interviews were conducted with his parents and teachers to ascertain the boy's psycho-educational support needs. Medical reports provided information on the complexities and prognosis of the syndrome. Observations in the classroom corroborated the learner's symptoms and behaviours. Results Thematic content analysis revealed the key areas of support needs. Gezani's cognitive disability required a modified, slow-paced curriculum. His visual impairment required mobility orientation training and learning Braille. His emotional needs were supported with psychotherapy to maintain a sense of well-being. Medical monitoring was recommended with interventions for walking and managing his diet and weight. Speech therapy supported his communication skills. Conclusion Learners with multiple disabilities require carefully planned, individualised psycho-educational support programmes addressing their unique needs and delays with targeted remedial interventions in appropriate special needs schools. Contribution This study informs educators about BBS and provides multi-faceted, holistic support. The Department of Basic Education could bring special schools and national policies in tighter alignment for learners presenting with complex disabilities.
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Affiliation(s)
- Mfungana M Shikwambana
- Department of Educational Psychology, Faculty of Education, University of Johannesburg, Johannesburg, South Africa
| | - Jean V Fourie
- Department of Educational Psychology, Faculty of Education, University of Johannesburg, Johannesburg, South Africa
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Ali A, Abdullah, Bilal M, Mis EK, Lakhani SA, Ahmad W, Ullah I. Sequence variants in different genes underlying Bardet-Biedl syndrome in four consanguineous families. Mol Biol Rep 2023; 50:9963-9970. [PMID: 37897612 DOI: 10.1007/s11033-023-08816-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 09/11/2023] [Indexed: 10/30/2023]
Abstract
BACKGROUND Bardet-Biedl Syndrome (BBS) is a rare (1:13,500-1-160,000) heterogeneous congenital disorder, characterized by postaxial polydactyly, obesity, hypogonadism, rod-cone dystrophy, cognitive impairment, and renal abnormalities (renal cystic dysplasia, anatomical malformation). To date about twenty-five genes have been identified to cause BBS, which accounts for about 80% of BBS diagnosis. METHODS In the current study, we have performed mutational screening of four Pakistani consanguineous families (A-D) with clinical manifestation of BBS by microsatellite-based genotyping and whole exome sequencing. RESULTS Analysis of the data revealed four variants, including a novel/unique inheritance pattern of compound heterozygous variants, p.(Ser40*) and p.(Thr259Leufs*21), in MKKS gene, novel homozygous variant, p.(Gly251Val)] in BBS7 gene and two previously reported p.(Thr259Leufs*21) in MKKS and p.(Met1Lys) in BBS5 gene. The variants were found segregated with the disorder within the families. CONCLUSION The study not only expanded mutations spectrum in the BBS genes, but this will facilitate diagnosis and genetic counselling of families carrying BBS related phenotypes in Pakistani population.
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Affiliation(s)
- Amjad Ali
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Abdullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
- Pediatric Genome Discovery Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Muhammad Bilal
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Emily Kathryn Mis
- Pediatric Genome Discovery Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Saquib Ali Lakhani
- Pediatric Genome Discovery Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Imran Ullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
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Tasaki K, Zhou Z, Ishida Y, Katoh Y, Nakayama K. Compound heterozygous IFT81 variations in a skeletal ciliopathy patient cause Bardet-Biedl syndrome-like ciliary defects. Hum Mol Genet 2023; 32:2887-2900. [PMID: 37427975 DOI: 10.1093/hmg/ddad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/04/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023] Open
Abstract
Owing to their crucial roles in development and homeostasis, defects in cilia cause ciliopathies with diverse clinical manifestations. The intraflagellar transport (IFT) machinery, containing the IFT-A and IFT-B complexes, mediates not only the intraciliary bidirectional trafficking but also import and export of ciliary proteins together with the kinesin-2 and dynein-2 motor complexes. The BBSome, containing eight subunits encoded by causative genes of Bardet-Biedl syndrome (BBS), connects the IFT machinery to ciliary membrane proteins to mediate their export from cilia. Although mutations in subunits of the IFT-A and dynein-2 complexes cause skeletal ciliopathies, mutations in some IFT-B subunits are also known to cause skeletal ciliopathies. We here show that compound heterozygous variations of an IFT-B subunit, IFT81, found in a patient with skeletal ciliopathy cause defects in its interactions with other IFT-B subunits, and in ciliogenesis and ciliary protein trafficking when one of the two variants was expressed in IFT81-knockout (KO) cells. Notably, we found that IFT81-KO cells expressing IFT81(Δ490-519), which lacks the binding site for the IFT25-IFT27 dimer, causes ciliary defects reminiscent of those found in BBS cells and those in IFT74-KO cells expressing a BBS variant of IFT74, which forms a heterodimer with IFT81. In addition, IFT81-KO cells expressing IFT81(Δ490-519) in combination with the other variant, IFT81 (L645*), which mimics the cellular conditions of the above skeletal ciliopathy patient, demonstrated essentially the same phenotype as those expressing only IFT81(Δ490-519). Thus, our data indicate that BBS-like defects can be caused by skeletal ciliopathy variants of IFT81.
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Affiliation(s)
- Koshi Tasaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Zhuang Zhou
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
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Khan S, Focșa IO, Budișteanu M, Stoica C, Nedelea F, Bohîlțea L, Caba L, Butnariu L, Pânzaru M, Rusu C, Jurcă C, Chirita-Emandi A, Bănescu C, Abbas W, Sadeghpour A, Baig SM, Bălgrădean M, Davis EE. Exome sequencing in a Romanian Bardet-Biedl syndrome cohort revealed an overabundance of causal BBS12 variants. Am J Med Genet A 2023; 191:2376-2391. [PMID: 37293956 PMCID: PMC10524726 DOI: 10.1002/ajmg.a.63322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/16/2023] [Accepted: 05/26/2023] [Indexed: 06/10/2023]
Abstract
Bardet-Biedl syndrome (BBS), is an emblematic ciliopathy hallmarked by pleiotropy, phenotype variability, and extensive genetic heterogeneity. BBS is a rare (~1/140,000 to ~1/160,000 in Europe) autosomal recessive pediatric disorder characterized by retinal degeneration, truncal obesity, polydactyly, cognitive impairment, renal dysfunction, and hypogonadism. Twenty-eight genes involved in ciliary structure or function have been implicated in BBS, and explain the molecular basis for ~75%-80% of individuals. To investigate the mutational spectrum of BBS in Romania, we ascertained a cohort of 24 individuals in 23 families. Following informed consent, we performed proband exome sequencing (ES). We detected 17 different putative disease-causing single nucleotide variants or small insertion-deletions and two pathogenic exon disruptive copy number variants in known BBS genes in 17 pedigrees. The most frequently impacted genes were BBS12 (35%), followed by BBS4, BBS7, and BBS10 (9% each) and BBS1, BBS2, and BBS5 (4% each). Homozygous BBS12 p.Arg355* variants were present in seven pedigrees of both Eastern European and Romani origin. Our data show that although the diagnostic rate of BBS in Romania is likely consistent with other worldwide cohorts (74%), we observed a unique distribution of causal BBS genes, including overrepresentation of BBS12 due to a recurrent nonsense variant, that has implications for regional diagnostics.
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Affiliation(s)
- Sheraz Khan
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Human Molecular Genetics Lab, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Ina Ofelia Focșa
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Cytogenomic Medical Laboratory, Bucharest, Romania
| | - Magdalena Budișteanu
- Psychiatry Research Laboratory, "Prof. Dr. Alexandru Obregia" Clinical Hospital of Psychiatry, Bucharest, Romania
- Medical Genetic Laboratory, "Victor Babeș" National Institute of Pathology, Bucharest, Romania
- Department of Medical Genetics, Faculty of Medicine, "Titu Maiorescu" University, Bucharest, Romania
| | - Cristina Stoica
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Department of Pediatrics, Clinical Institute Fundeni, Bucharest, Romania
| | - Florina Nedelea
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Genetics Department, Clinical Hospital Filantropia, Bucharest, Romania
| | | | - Lavinia Caba
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
| | - Lăcrămioara Butnariu
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Monica Pânzaru
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Cristina Rusu
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Claudia Jurcă
- Department of Genetics, Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania
- Department of Pediatrics, "Dr. Gavril Curteanu" Municipal Clinical Hospital, Oradea, Romania
| | - Adela Chirita-Emandi
- Emergency Hospital for Children Louis Turcanu, Regional Center of Medical Genetics Timis, Timisoara, Romania
- Victor Babes University of Medicine and Pharmacy Timisoara, Department of Microscopic Morphology Genetics, Center for Genomic Medicine, Timisoara, Romania
| | - Claudia Bănescu
- "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology, Târgu Mureş, Romania
| | - Wasim Abbas
- Human Molecular Genetics Lab, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina, USA
- Duke Precision Medicine Program, Department of Medicine, Division of General Internal Medicine, Duke University Medical Center, Durham, NC, USA
| | - Shahid Mahmood Baig
- Pakistan Science Foundation (PSF), Islamabad, Pakistan
- Department of Biological and Biomedical Sciences, Agha Khan University Karachi, Karachi, Pakistan
| | - Mihaela Bălgrădean
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children "Maria Skłodowska Curie", Bucharest, Romania
| | - Erica E Davis
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Department of Pediatrics and Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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11
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Forsythe E, Mallya UG, Yang M, Huber C, Cala ML, Greatsinger A, Hagopian E, Pomeroy J, Haqq AM. Caregiver burden in Bardet-Biedl syndrome: findings from the CARE-BBS study. Orphanet J Rare Dis 2023; 18:181. [PMID: 37415214 DOI: 10.1186/s13023-023-02692-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/02/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare, genetically heterogeneous obesity syndrome associated with hyperphagia. Given the early onset of BBS symptoms in childhood and multifaceted complications, this study aimed to quantify the caregiver burden associated with BBS. METHODS A cross-sectional, multi-country survey of caregivers from the United States (US), United Kingdom (UK), Canada, and Germany was designed to quantify the extent of caregiver burden associated with obesity and hyperphagia symptoms (i.e., uncontrollable hunger) among patients with BBS. RESULTS A total of 242 caregivers across the four countries met the inclusion criteria and completed the survey. The mean (standard deviation [SD]) age of the caregivers was 41.9 (6.7) years, and the mean (SD) age of individuals with BBS in their care was 12.0 (3.7) years. Hyperphagia contributed to a BBS diagnosis in 230 of 242 individuals (95.0%). On average, caregivers used eight different weight management approaches for those in their care and expressed a strong desire for more effective weight management methods. Based on the Impacts of Hyperphagia: Caregiver version, patients' hyperphagia had a moderate-to-severe impact on caregiver mood (56.6%), sleep (46.6%), and relationships (48.0%). Caregivers reported experiencing a high level of personal strain (mean [SD], 17.1 [2.9]) and family impact (mean [SD] score, 26.0 [3.8]) due to BBS, as measured by the Revised Impact on Family Scale. Among caregivers in the workforce, there also was high impairment in total work productivity (mean [SD], 60.9% [21.4%]) due to caring for patients with BBS according to the Work Productivity and Activity Impairment. More than half (53%) of the caregivers reported spending over 5,000 out-of-pocket in local currency for medical expenses for the patient with BBS in their care. CONCLUSIONS Obesity and hyperphagia have negative impacts on the lives of caregivers of patients with BBS. The burden is demonstrated to be multifaceted, with various components that may interact with and confound each other, including intensive weight management efforts, productivity loses, impaired family dynamics and out-of-pocket medical expenses.
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Affiliation(s)
- Elizabeth Forsythe
- University College London Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK.
| | | | - Min Yang
- Analysis Group, Inc., Boston, MA, USA
| | | | | | | | | | - Jeremy Pomeroy
- Marshfield Clinic Research Institute, Marshfield, WI, USA
| | - Andrea M Haqq
- Division of Pediatric Endocrinology, University of Alberta, Edmonton, AB, Canada
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12
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Forsythe E, Mallya UG, Yang M, Huber C, Cala ML, Greatsinger A, Hagopian E, Pomeroy J, Haqq AM. Burden of hyperphagia and obesity in Bardet-Biedl syndrome: a multicountry survey. Orphanet J Rare Dis 2023; 18:182. [PMID: 37415189 DOI: 10.1186/s13023-023-02723-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/11/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND Signs and symptoms of Bardet-Biedl syndrome (BBS) occur during early childhood, progress over time, and place substantial, multifaceted burden on patients and their caregivers. Hyperphagia may be a contributing factor to early-onset obesity in BBS; however, there are limited insights into its impacts on patients and caregivers. We quantified disease burden as it relates to the physical and emotional impacts of hyperphagia in BBS. METHODS The CAREgiver Burden in BBS (CARE-BBS) study was a multicountry, cross-sectional survey of adult caregivers of patients with BBS who have had hyperphagia and obesity. The survey consisted of questionnaires including Symptoms of Hyperphagia, Impacts of Hyperphagia, Impact of Weight on Quality of Life (IWQOL)-Kids Parent Proxy, and Patient-Reported Outcome Measurement Information System (PROMIS) v1.0-Global Health 7. In addition, clinical characteristics, medical history, and weight management questions were included. Outcomes were scored and summarized descriptively in aggregate and by country, age, and obesity severity according to weight class. RESULTS There were 242 caregivers of patients with BBS who completed the survey. Caregivers observed hyperphagic behaviors throughout the day, with negotiating for food (90%) and waking up and asking or looking for food during the night (88%) being the most frequent. Hyperphagia had at least a moderate negative impact on most patients' mood/emotions (56%), sleep (54%), school (57%), leisure (62%), and familial relationships (51%). Hyperphagia affected concentration at school (78%), and symptoms of BBS contributed to patients missing ≥ 1 day of school a week (82%). Responses from the IWQOL-Kids Parent Proxy suggested obesity most greatly negatively affected physical comfort (mean [standard deviation (SD)], 41.7 [17.2]), body esteem (41.0 [17.8]), and social life (41.7 [18.0]). On the PROMIS questionnaire, mean (SD) global health score for pediatric patients with BBS and overweight or obesity (36.8 [10.6]) was lower than the general population (mean, 50). CONCLUSIONS Evidence from this study suggests that hyperphagia and obesity may have broad negative impacts on the lives of patients with BBS, including physical health, emotional well-being, school performance, and personal relationships. Therapies that target hyperphagia may alleviate the extensive clinical and nonclinical impacts experienced by patients with BBS and their caregivers.
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Affiliation(s)
- Elizabeth Forsythe
- Clinical Genetics Department, Guy's Hospital, and National Bardet-Biedl Syndrome Clinics, Great Ormond Street and St Thomas' Hospitals, London, UK
| | | | | | | | | | | | | | - Jeremy Pomeroy
- Marshfield Clinic Research Institute, Marshfield, WI, USA
| | - Andrea M Haqq
- Department of Pediatrics, University of Alberta, 8440 - 112 St NW, Edmonton, AB, T6G 2B7, Canada.
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Lindovsky J, Nichtova Z, Dragano NRV, Pajuelo Reguera D, Prochazka J, Fuchs H, Marschall S, Gailus-Durner V, Sedlacek R, Hrabě de Angelis M, Rozman J, Spielmann N. A review of standardized high-throughput cardiovascular phenotyping with a link to metabolism in mice. Mamm Genome 2023; 34:107-122. [PMID: 37326672 PMCID: PMC10290615 DOI: 10.1007/s00335-023-09997-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 05/03/2023] [Indexed: 06/17/2023]
Abstract
Cardiovascular diseases cause a high mortality rate worldwide and represent a major burden for health care systems. Experimental rodent models play a central role in cardiovascular disease research by effectively simulating human cardiovascular diseases. Using mice, the International Mouse Phenotyping Consortium (IMPC) aims to target each protein-coding gene and phenotype multiple organ systems in single-gene knockout models by a global network of mouse clinics. In this review, we summarize the current advances of the IMPC in cardiac research and describe in detail the diagnostic requirements of high-throughput electrocardiography and transthoracic echocardiography capable of detecting cardiac arrhythmias and cardiomyopathies in mice. Beyond that, we are linking metabolism to the heart and describing phenotypes that emerge in a set of known genes, when knocked out in mice, such as the leptin receptor (Lepr), leptin (Lep), and Bardet-Biedl syndrome 5 (Bbs5). Furthermore, we are presenting not yet associated loss-of-function genes affecting both, metabolism and the cardiovascular system, such as the RING finger protein 10 (Rfn10), F-box protein 38 (Fbxo38), and Dipeptidyl peptidase 8 (Dpp8). These extensive high-throughput data from IMPC mice provide a promising opportunity to explore genetics causing metabolic heart disease with an important translational approach.
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Affiliation(s)
- Jiri Lindovsky
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Zuzana Nichtova
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Nathalia R. V. Dragano
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - David Pajuelo Reguera
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Jan Prochazka
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Susan Marschall
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Radislav Sedlacek
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Jan Rozman
- Czech Centre for Phenogenomics, Institute of Molecular Genetics, Czech Academy of Sciences, Prumyslova 595, 252 50 Vestec, Czech Republic
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Nadine Spielmann
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
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14
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Ervin C, Norcross L, Mallya UG, Fehnel S, Mittleman RS, Webster M, Haqq AM, Haws RM. Interview-Based Patient- and Caregiver-Reported Experiences of Hunger and Improved Quality of Life with Setmelanotide Treatment in Bardet-Biedl Syndrome. Adv Ther 2023; 40:2394-2411. [PMID: 36961653 PMCID: PMC10036981 DOI: 10.1007/s12325-023-02443-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/25/2023] [Indexed: 03/25/2023]
Abstract
INTRODUCTION Bardet-Biedl syndrome (BBS) is a rare genetic disease associated with hyperphagia, a pathologic insatiable hunger, due to impaired signaling in the melanocortin-4 receptor (MC4R) pathway. The impact of hyperphagia on the lives of patients with BBS and their families has not been fully characterized. METHODS Patients with BBS or their caregivers who participated in clinical trials of the MC4R agonist setmelanotide (NCT03013543 and NCT03746522) were included in this qualitative study. Telephone interviews were conducted using a semistructured interview guide to explore patient experience and caregiver observations of hyperphagia before and during setmelanotide treatment. RESULTS Nineteen interviews (8 patients, 11 caregivers) were conducted. The term "hunger" (rather than "hyperphagia") was used in interviews to ensure common terminology. Before setmelanotide treatment, all participants described their (or their child's) hunger as all-consuming, leading to an obsessive focus on food. Nine participants recalled intense, continuous hunger, and most participants (5 patients, 10 caregivers) reported lack of control with eating. Negative impacts on patients' lives included difficulties with concentration, emotional and physical manifestations, and impaired relationships. All participants experienced or observed improvements in hunger and health outcomes during treatment, the most meaningful of which included weight loss and decrease in obsessive focus on food and food-seeking behaviors. All participants reported improvements in either physical and/or emotional well-being and being satisfied with setmelanotide. CONCLUSIONS Hyperphagia and resulting food-seeking behaviors have notable negative impacts on quality of life in patients with BBS and caregivers. Setmelanotide improved hyperphagia, reduced body weight and obsessive focus on food, and facilitated improvements in physical and emotional well-being for both patients and caregivers. TRIAL REGISTRATION NCT03013543 and NCT03746522.
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Affiliation(s)
- Claire Ervin
- RTI Health Solutions, 3040 E Cornwallis Rd, PO Box 12194, Research Triangle Park, NC 27709-2194 USA
| | - Lindsey Norcross
- RTI Health Solutions, 3040 E Cornwallis Rd, PO Box 12194, Research Triangle Park, NC 27709-2194 USA
| | - Usha G. Mallya
- Rhythm Pharmaceuticals, Inc., 222 Berkeley Street, 12th Floor, Boston, MA 02116 USA
| | - Sheri Fehnel
- RTI Health Solutions, 3040 E Cornwallis Rd, PO Box 12194, Research Triangle Park, NC 27709-2194 USA
| | - Robert S. Mittleman
- Rhythm Pharmaceuticals, Inc., 222 Berkeley Street, 12th Floor, Boston, MA 02116 USA
| | - Matthew Webster
- Rhythm Pharmaceuticals, Inc., 222 Berkeley Street, 12th Floor, Boston, MA 02116 USA
| | - Andrea M. Haqq
- University of Alberta, 6-002E Li Ka Shing Centre for Health Research Innovation, Edmonton, AB T6G 2E1 Canada
| | - Robert M. Haws
- Marshfield Clinic Research Institute, 1000 North Oak Avenue, Marshfield, WI 54449 USA
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Lazareva J, Brady SM, Yanovski JA. An evaluation of setmelanotide injection for chronic weight management in adult and pediatric patients with obesity due to Bardet-Biedl syndrome. Expert Opin Pharmacother 2023; 24:667-674. [PMID: 37013719 PMCID: PMC10121918 DOI: 10.1080/14656566.2023.2199152] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/31/2023] [Indexed: 04/05/2023]
Abstract
INTRODUCTION Bardet-Biedl Syndrome (BBS) is a rare, multisystemic ciliopathy with an incidence of obesity of 89%. Mutations in genes encoding BBS proteins are linked to reduced leptin sensitivity of hypothalamic POMC neurons and reduced activation of the melanocortin-4 receptor (MC4R) pathway due to deficient α-MSH production by hypothalamic POMC neurons. The MC4R pathway is involved in controlling body weight and energy metabolism, and its disruption is linked to hyperphagia and obesity. Setmelanotide is an MC4R agonist that counteracts deficiencies in the MC4R pathway of individuals with BBS. AREAS COVERED Data from clinical trials were reviewed along with information available from setmelanotide's approval for treatment of obesity in people ages ≥6y with a clinical diagnosis of BBS. EXPERT OPINION Setmelanotide is available as a daily injectable that can be used for amelioration of obesity in people with Bardet-Biedl syndrome. Its cost is substantial, which may limit its use, but among those who respond, setmelanotide can reduce body mass dramatically and potentially improve comorbid conditions associated with obesity. Setmelanotide treatment has generally tolerable side effects, primarily injection site reactions and nausea/vomiting that generally improve with continued use; almost all people using setmelanotide experience marked skin darkening due to off-target activation of cutaneous MC1R.
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Affiliation(s)
- Julia Lazareva
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Section on Growth and Obesity, Maryland, United States
| | - Sheila M. Brady
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Section on Growth and Obesity, Maryland, United States
| | - Jack A. Yanovski
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Section on Growth and Obesity, Maryland, United States
- The National Institutes of Health, Maryland, United States
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16
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DeMars KM, Ross MR, Starr A, McIntyre JC. Neuronal primary cilia integrate peripheral signals with metabolic drives. Front Physiol 2023; 14:1150232. [PMID: 37064917 PMCID: PMC10090425 DOI: 10.3389/fphys.2023.1150232] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
Neuronal primary cilia have recently emerged as important contributors to the central regulation of energy homeostasis. As non-motile, microtubule-based organelles, primary cilia serve as signaling antennae for metabolic status. The impairment of ciliary structure or function can produce ciliopathies for which obesity is a hallmark phenotype and global ablation of cilia induces non-syndromic adiposity in mouse models. This organelle is not only a hub for metabolic signaling, but also for catecholamine neuromodulation that shapes neuronal circuitry in response to sensory input. The objective of this review is to highlight current research investigating the mechanisms of primary cilium-regulated metabolic drives for maintaining energy homeostasis.
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Affiliation(s)
- Kelly M. DeMars
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Madeleine R. Ross
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Summer Neuroscience Internship Program, University of Florida, Gainesville, FL, United States
| | - Alana Starr
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Jeremy C. McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
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Baig S, Wanninayake S, Foggensteiner L, Elhassan YS, Manolopoulos K, Ali S, Lassen PB, Clément K, Steeds RP, Tomlinson JW, Geberhiwot T. Adipose tissue function and insulin sensitivity in syndromic obesity of Bardet-Biedl syndrome. Int J Obes (Lond) 2023. [PMID: 36807608 DOI: 10.1038/s41366-023-01280-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/22/2023]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare autosomal recessive syndromic obesity of childhood onset among many other features. To date, the excess risk of metabolic complications of severe early-onset obesity in BBS remains controversial. In-depth investigation of adipose tissue structure and function with detailed metabolic phenotype has not been investigated yet. OBJECTIVE To investigate adipose tissue function in BBS. DESIGN A prospective cross-sectional study. MAIN OUTCOME MEASURE To determine if there are differences in insulin resistance, metabolic profile, adipose tissue function and gene expression in patients with BBS compared to BMI-matched polygenic obese controls. METHOD 9 adults with BBS and 10 controls were recruited from the national centre for BBS, Birmingham, UK. An in-depth study of adipose tissue structure and function along with insulin sensitivity was performed using hyperinsulinemic-euglycemic clamp studies, adipose tissue microdialysis, histology and RNA sequencing, and measurement of circulating adipokines and inflammatory biomarkers. RESULTS Adipose tissue structure, gene expression and in vivo functional analysis between BBS and polygenic obesity cohorts were similar. Using hyperinsulinemic-euglycemic clamp and surrogate markers of insulin resistance, we found no significant differences in insulin sensitivity between BBS and obese controls. Furthermore, no significant changes were noted in an array of adipokines, cytokines, pro-inflammatory markers and adipose tissue RNA transcriptomic. CONCLUSION Although childhood-onset extreme obesity is a feature of BBS, detailed studies of insulin sensitivity and adipose tissue structure and function are similar to common polygenic obesity. This study adds to the literature by suggesting that it is the quality and quantity of adiposity not the duration that drives the metabolic phenotype.
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Abstract
PURPOSE OF REVIEW Bardet Biedl syndrome (BBS) is a rare disease characterized by obesity and hyperphagia. Despite the very high prevalence of paediatric and adult obesity in this population, the prevalence of diabetes mellitus is not well described. RECENT FINDINGS Studies in small and moderately large cohorts suggest a high prevalence of traditional risk factors for diabetes mellitus in people with BBS. People with BBS appear to have a high prevalence of insulin resistance and metabolic syndrome. Small cohort studies have identified high rates of sleep disordered breathing, including sleep apnoea syndrome. Recent research has characterized traditional behavioural risk factors such as sleep hygiene and physical inactivity in people with BBS. High rates of insufficient sleep and prolonged sedentary time suggest behavioural targets of interventions to treat or prevent diabetes mellitus. Hyperphagia, likely caused by defects in the hypothalamic melanocortin-4 receptor (MC4R) neuronal pathway, pose additional challenges to behavioural interventions to prevent diabetes mellitus. SUMMARY Understanding the prevalence of diabetes mellitus and other metabolic disorders in people with BBS and the impact of traditional risk factors on glucose regulation are important to developing effective treatments in this population.
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Affiliation(s)
- Jeremy Pomeroy
- Center of Excellence for Bardet Biedl Syndrome, Marshfield Clinic Research Institute
| | - Kelsi-Marie Offenwanger
- Center of Excellence for Bardet Biedl Syndrome, Department of Psychiatry & Behavioral Health
| | - Tammi Timmler
- Center of Excellence for Bardet Biedl Syndrome, Dietetics, Marshfield Clinic Health System, Marshfield, Wisconsin, USA
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19
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Melluso A, Secondulfo F, Capolongo G, Capasso G, Zacchia M. Bardet-Biedl Syndrome: Current Perspectives and Clinical Outlook. Ther Clin Risk Manag 2023; 19:115-132. [PMID: 36741589 PMCID: PMC9896974 DOI: 10.2147/tcrm.s338653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
The Bardet Biedl syndrome (BBS) is a rare inherited disorder considered a model of non-motile ciliopathy. It is in fact caused by mutations of genes encoding for proteins mainly localized to the base of the cilium. Clinical features of BBS patients are widely shared with patients suffering from other ciliopathies, especially autosomal recessive syndromic disorders; moreover, mutations in cilia-related genes can cause different clinical ciliopathy entities. Besides the best-known clinical features, as retinal degeneration, learning disabilities, polydactyly, obesity and renal defects, several additional clinical signs have been reported in BBS, expanding our understanding of the complexity of its clinical spectrum. The present review aims to describe the current knowledge of BBS i) pathophysiology, ii) clinical manifestations, highlighting both the most common and the less described features, iii) current and future perspective for treatment.
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Affiliation(s)
- Andrea Melluso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Floriana Secondulfo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy,Biogem Scarl, Ariano Irpino, AV, 83031, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy,Correspondence: Miriam Zacchia, Via Pansini 5, Naples, 80131, Italy, Tel +39 081 566 6650, Fax +39 081 566 6671, Email
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Forsythe E, Haws RM, Argente J, Beales P, Martos-Moreno GÁ, Dollfus H, Chirila C, Gnanasakthy A, Buckley BC, Mallya UG, Clément K, Haqq AM. Quality of life improvements following one year of setmelanotide in children and adult patients with Bardet-Biedl syndrome: phase 3 trial results. Orphanet J Rare Dis 2023; 18:12. [PMID: 36647077 PMCID: PMC9841937 DOI: 10.1186/s13023-022-02602-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/19/2022] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Bardet-Biedl syndrome is a rare genetic disease associated with hyperphagia and early-onset, severe obesity. There is limited evidence on how hyperphagia and obesity affect health-related quality of life in patients with Bardet-Biedl syndrome, and on how management of these symptoms may influence disease burden. This analysis evaluated changes in health-related quality of life in adults and children with Bardet-Biedl syndrome in a Phase 3 trial following 1 year of setmelanotide treatment (ClinicalTrials.gov identifier: NCT03746522). METHODS Patients with Bardet-Biedl syndrome and obesity received 52 weeks of treatment with setmelanotide and completed various self-reported health-related quality of life measures. Patients aged < 18 years or their caregiver completed the Pediatric Quality of Life Inventory (PedsQL; meaningful improvement, 4.4-point change); adults aged ≥ 18 years completed the Impact of Weight on Quality of Life Questionnaire-Lite (IWQOL-Lite; meaningful improvement range, 7.7-12-point change). Descriptive outcomes were reported in patients with data both at active treatment baseline and after 52 weeks of treatment. RESULTS Twenty patients (< 18 years, n = 9; ≥ 18 years, n = 11) reported health-related quality of life at baseline and 52 weeks. For children and adolescents, PedsQL score mean change from baseline after 52 weeks was + 11.2; all patients with PedsQL impairment at baseline (n = 4) experienced clinically meaningful improvement. In adults, IWQOL-Lite score mean change from baseline was + 12.0. Of adults with IWQOL-Lite impairment at baseline (n = 8), 62.5% experienced clinically meaningful improvement. In adults, IWQOL-Lite score was significantly correlated with changes in percent body weight (P = 0.0037) and body mass index (P = 0.0098). CONCLUSIONS After 1 year of setmelanotide, patients reported clinically meaningful improvements across multiple health-related quality of life measures. This study highlights the need to address the impaired health-related quality of life in Bardet-Biedl syndrome, and supports utility of setmelanotide for reducing this burden. Trial Registration NCT03746522. Registered November 19, 2018, https://clinicaltrials.gov/ct2/show/NCT03746522 .
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Affiliation(s)
- Elizabeth Forsythe
- grid.83440.3b0000000121901201Genetics and Genomics Medicine Programme, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Robert M. Haws
- grid.280718.40000 0000 9274 7048Marshfield Clinic Research Institute, Marshfield, WI USA
| | - Jesús Argente
- grid.5515.40000000119578126Department of Pediatrics and Pediatric Endocrinology, Universidad Autónoma de Madrid, University Hospital Niño Jesús, Madrid, Spain ,grid.413448.e0000 0000 9314 1427CIBER “Fisiopatología de la Obesidad y Nutrición” (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain ,grid.482878.90000 0004 0500 5302IMDEA Food Institute, Madrid, Spain
| | - Philip Beales
- grid.83440.3b0000000121901201Genetics and Genomics Medicine Programme, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Gabriel Á. Martos-Moreno
- grid.5515.40000000119578126Department of Pediatrics and Pediatric Endocrinology, Universidad Autónoma de Madrid, University Hospital Niño Jesús, Madrid, Spain ,grid.413448.e0000 0000 9314 1427CIBER “Fisiopatología de la Obesidad y Nutrición” (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Hélène Dollfus
- grid.412220.70000 0001 2177 138XHôpitaux Universitaires de Strasbourg, CARGO and Department of Medical Genetics, Strasbourg, France
| | - Costel Chirila
- grid.62562.350000000100301493RTI Health Solutions, Research Triangle Park, NC USA
| | - Ari Gnanasakthy
- grid.62562.350000000100301493RTI Health Solutions, Research Triangle Park, NC USA
| | | | - Usha G. Mallya
- grid.476681.aRhythm Pharmaceuticals, Inc., Boston, MA USA
| | - Karine Clément
- grid.411439.a0000 0001 2150 9058Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, Paris, France ,Sorbonne Université, INSERM, NutriOmics Research Unit, Paris, France
| | - Andrea M. Haqq
- grid.17089.370000 0001 2190 316XDivision of Pediatric Endocrinology, University of Alberta, 6-002E Li Ka Shing Centre for Health Research Innovation, Edmonton, AB T6G 2E1 Canada
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21
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Brewer KM, Brewer KK, Richardson NC, Berbari NF. Neuronal cilia in energy homeostasis. Front Cell Dev Biol 2022; 10:1082141. [PMID: 36568981 PMCID: PMC9773564 DOI: 10.3389/fcell.2022.1082141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 11/11/2022] [Indexed: 12/13/2022] Open
Abstract
A subset of genetic disorders termed ciliopathies are associated with obesity. The mechanisms behind cilia dysfunction and altered energy homeostasis in these syndromes are complex and likely involve deficits in both development and adult homeostasis. Interestingly, several cilia-associated gene mutations also lead to morbid obesity. While cilia have critical and diverse functions in energy homeostasis, including their roles in centrally mediated food intake and peripheral tissues, many questions remain. Here, we briefly discuss syndromic ciliopathies and monogenic cilia signaling mutations associated with obesity. We then focus on potential ways neuronal cilia regulate energy homeostasis. We discuss the literature around cilia and leptin-melanocortin signaling and changes in ciliary G protein-coupled receptor (GPCR) signaling. We also discuss the different brain regions where cilia are implicated in energy homeostasis and the potential for cilia dysfunction in neural development to contribute to obesity. We close with a short discussion on the challenges and opportunities associated with studies looking at neuronal cilia and energy homeostasis. This review highlights how neuronal cilia-mediated signaling is critical for proper energy homeostasis.
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Affiliation(s)
- Kathryn M. Brewer
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Katlyn K. Brewer
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Nicholas C. Richardson
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Nicolas F. Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States,Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, United States,Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, United States,*Correspondence: Nicolas F. Berbari,
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22
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Littleton SH, Grant SFA. Strategies to identify causal common genetic variants and corresponding effector genes for paediatric obesity. Pediatr Obes 2022; 17:e12968. [PMID: 35971868 DOI: 10.1111/ijpo.12968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/24/2022] [Accepted: 08/01/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Childhood obesity rates are on the rise, but there are currently no effective therapies available to slow or halt their progression. Although environmental and lifestyle factors have been implicated in its pathogenesis, childhood obesity is considered a complex disorder with a clear genetic component. Intense genome-wide association study (GWAS) efforts through large-scale collaborations have enabled the discovery of genetic loci robustly associated with childhood obesity beyond the classic FTO locus. That said, GWAS itself does not pinpoint the actual underlying causal effector genes, but rather just yields association signals in the genome. OBJECTIVE This review aims to outline what has been elucidated thus far on the genetic aetiology of commong childhood obesity and to describe strategies to identify and validate both causal common genetic variants and their corresponding effector genes. RESULTS Relevant cell types for molecular studies can be identified by gene set enrichment analysis and considering known biology of obesity-related physiological processes. Putatively causal single nucleotide polymorphisms (SNPs) can be identified by several methods including statistical fine mapping and 'assay for transposase accessible chromatin sequencing' (ATAC-seq). Variant to gene mapping can then nominate effector genes likely regulated by cis-regulatory elements harbouring putatively causal SNPs. A SNP's cis-regulatory activity can be functionally validated by several in vitro methods including luciferase assay and CRISPR approaches. These CRISPR approaches can also be used to investigate how dysregulatn of effector genes may confer obesity risk. CONCLUSION Uncovering the causative genes related to GWAS signals and elucidating their functional contributions to paediatric obesity with these strategies will deepen our understanding of this disease and serve better treatment outcomes.
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Affiliation(s)
- Sheridan H Littleton
- Center for Spatial and Functional Genomics, Children's Hospital of Philadelphia, Philadelphia, USA.,Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA.,Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA
| | - Struan F A Grant
- Center for Spatial and Functional Genomics, Children's Hospital of Philadelphia, Philadelphia, USA.,Divisons of Genetics and Endocrinology, Children's Hospital of Philadelphia, Philadelphia, USA.,Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA
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23
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Haqq AM, Chung WK, Dollfus H, Haws RM, Martos-Moreno GÁ, Poitou C, Yanovski JA, Mittleman RS, Yuan G, Forsythe E, Clément K, Argente J. Efficacy and safety of setmelanotide, a melanocortin-4 receptor agonist, in patients with Bardet-Biedl syndrome and Alström syndrome: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial with an open-label period. Lancet Diabetes Endocrinol 2022; 10:859-868. [PMID: 36356613 PMCID: PMC9847480 DOI: 10.1016/s2213-8587(22)00277-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Impaired cilial signalling in the melanocortin-4 receptor (MC4R) pathway might contribute to obesity in patients with Bardet-Biedl syndrome and Alström syndrome, rare genetic diseases associated with hyperphagia and early-onset severe obesity. We aimed to evaluate the effect of setmelanotide on bodyweight in these patients. METHODS This multicentre, randomised, 14-week double-blind, placebo-controlled, phase 3 trial followed by a 52-week open-label period, was performed at 12 sites (hospitals, clinics, and universities) in the USA, Canada, the UK, France, and Spain. Patients aged 6 years or older were included if they had a clinical diagnosis of Bardet-Biedl syndrome or Alström syndrome and obesity (defined as BMI >97th percentile for age and sex for those aged 6-15 years and ≥30 kg/m2 for those aged ≥16 years). Patients were randomly assigned (1:1) using a numerical randomisation code to receive up to 3·0 mg of subcutaneous setmelanotide or placebo once per day during the 14-week double-blind period, followed by open-label setmelanotide for 52 weeks. The primary endpoint, measured in the full analysis set, was the proportion of patients aged 12 years or older who reached at least a 10% reduction in bodyweight from baseline after 52 weeks of setmelanotide treatment. This study is registered with ClinicalTrials.gov, NCT03746522. FINDINGS Between Dec 10, 2018, and Nov 25, 2019, 38 patients were enrolled and randomly assigned to receive setmelanotide (n=19) or placebo (n=19; 16 with Bardet-Biedl syndrome and three with Alström syndrome in each group). In terms of the primary endpoint, 32·3% (95% CI 16·7 to 51·4; p=0·0006) of patients aged 12 years or older with Bardet-Biedl syndrome reached at least a 10% reduction in bodyweight after 52 weeks of setmelanotide. The most commonly reported treatment-emergent adverse events were skin hyperpigmentation (23 [61%] of 38) and injection site erythema (18 [48%]). Two patients had four serious adverse events (blindness, anaphylactic reaction, and suicidal ideation); none were considered related to setmelanotide treatment. INTERPRETATION Setmelanotide resulted in significant bodyweight reductions in patients with Bardet-Biedl syndrome; however, these results were inconclusive in patients with Alström syndrome. These results support the use of setmelanotide and provided the necessary evidence for approval of this drug as the first treatment for obesity in patients with Bardet-Biedl syndrome. FUNDING Rhythm Pharmaceuticals.
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Affiliation(s)
- Andrea M Haqq
- Division of Pediatric Endocrinology, University of Alberta, Edmonton, AB, Canada
| | - Wendy K Chung
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, New York, NY, USA
| | - Hélène Dollfus
- Department of Medical Genetics, CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Robert M Haws
- Marshfield Clinic Research Institute, Marshfield, WI, USA
| | - Gabriel Á Martos-Moreno
- Department of Pediatrics and Pediatric Endocrinology, Universidad Autónoma de Madrid, Hospital Infantil Universitario Niño Jesús, CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Christine Poitou
- Department of Nutrition, Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, INSERM, NutriOmics Research Unit, Paris, France
| | - Jack A Yanovski
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Elizabeth Forsythe
- University College London, Great Ormond Street Institute of Child Health, London, UK
| | - Karine Clément
- Department of Nutrition, Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, INSERM, NutriOmics Research Unit, Paris, France
| | - Jesús Argente
- Division of Pediatric Endocrinology, University of Alberta, Edmonton, AB, Canada; IMDEA Food Institute, Madrid, Spain.
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Caba L, Florea L, Braha EE, Lupu VV, Gorduza EV. Monitoring and Management of Bardet-Biedl Syndrome: What the Multi-Disciplinary Team Can Do. J Multidiscip Healthc 2022; 15:2153-2167. [PMID: 36193191 PMCID: PMC9526427 DOI: 10.2147/jmdh.s274739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 09/16/2022] [Indexed: 11/23/2022] Open
Abstract
Bardet – Biedl syndrome is a rare autosomal recessive multisystem non-motile ciliopathy. It has heterogeneous clinical manifestations. It is caused by mutations in 26 genes encoding BBSome proteins, chaperonines, and IFT complex. The main clinical features are: retinal cone-rod dystrophy, central obesity, postaxial polydactyly, cognitive impairment, hypogonadism and genitourinary anomalies, and kidney disease. The onset of clinical manifestations is variable which makes the diagnosis difficult in some patients. Because of the multiple system involvement, a multidisciplinary approach is necessary. The purpose of this review is to provide monitoring and management directions for a better approach to these patients.
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Affiliation(s)
- Lavinia Caba
- Department of Mother and Child Medicine – Medical Genetics, “Grigore T. Popa” University of Medicine and Pharmacy, Iaşi, Romania
- Correspondence: Lavinia Caba, Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 16 University Street, Iasi, 700115, Romania, Email
| | - Laura Florea
- Department of Nephrology - Internal Medicine, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, Iasi, Romania
| | | | - Valeriu Vasile Lupu
- Department of Mother and Child Medicine – Pediatrics, “Grigore T. Popa” University of Medicine and Pharmacy, Iaşi, Romania
| | - Eusebiu Vlad Gorduza
- Department of Mother and Child Medicine – Medical Genetics, “Grigore T. Popa” University of Medicine and Pharmacy, Iaşi, Romania
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Abstract
A primary cilium, a hair-like protrusion of the plasma membrane, is a pivotal organelle for sensing external environmental signals and transducing intracellular signaling. An interesting linkage between cilia and obesity has been revealed by studies of the human genetic ciliopathies Bardet-Biedl syndrome and Alström syndrome, in which obesity is a principal manifestation. Mouse models of cell type-specific cilia dysgenesis have subsequently demonstrated that ciliary defects restricted to specific hypothalamic neurons are sufficient to induce obesity and hyperphagia. A potential mechanism underlying hypothalamic neuron cilia-related obesity is impaired ciliary localization of G protein-coupled receptors involved in the regulation of appetite and energy metabolism. A well-studied example of this is melanocortin 4 receptor (MC4R), mutations in which are the most common cause of human monogenic obesity. In the paraventricular hypothalamus neurons, a blockade of ciliary trafficking of MC4R as well as its downstream ciliary signaling leads to hyperphagia and weight gain. Another potential mechanism is reduced leptin signaling in hypothalamic neurons with defective cilia. Leptin receptors traffic to the periciliary area upon leptin stimulation. Moreover, defects in cilia formation hamper leptin signaling and actions in both developing and differentiated hypothalamic neurons. The list of obesity-linked ciliary proteins is expending and this supports a tight association between cilia and obesity. This article provides a brief review on the mechanism of how ciliary defects in hypothalamic neurons facilitate obesity.
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Affiliation(s)
- Chan Hee Lee
- Department of Biomedical Science, Hallym University, Chuncheon 24252, Korea
| | - Gil Myoung Kang
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Min-Seon Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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Meyer JR, Krentz AD, Berg RL, Richardson JG, Pomeroy J, Hebbring SJ, Haws RM. Kidney Failure in Bardet-Biedl Syndrome. Clin Genet 2022; 101:429-441. [PMID: 35112343 PMCID: PMC9311438 DOI: 10.1111/cge.14119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 11/29/2022]
Abstract
The aim of this study was to explore kidney failure (KF) in Bardet–Biedl syndrome (BBS), focusing on high‐risk gene variants, demographics, and morbidity. We employed the Clinical Registry Investigating BBS (CRIBBS) to identify 44 (7.2%) individuals with KF out of 607 subjects. Molecularly confirmed BBS was identified in 37 KF subjects and 364 CRIBBS registrants. KF was concomitant with recessive causal variants in 12 genes, with BBS10 the most predominant causal gene (26.6%), while disease penetrance was highest in SDCCAG8 (100%). Two truncating variants were present in 67.6% of KF cases. KF incidence was increased in genes not belonging to the BBSome or chaperonin‐like genes (p < 0.001), including TTC21B, a new candidate BBS gene. Median age of KF was 12.5 years, with the vast majority of KF occurring by 30 years (86.3%). Females were disproportionately affected (77.3%). Diverse uropathies were identified, but were not more common in the KF group (p = 0.672). Kidney failure was evident in 11 of 15 (73.3%) deaths outside infancy. We conclude that KF poses a significant risk for premature morbidity in BBS. Risk factors for KF include female sex, truncating variants, and genes other than BBSome/chaperonin‐like genes highlighting the value of comprehensive genetic investigation.
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Affiliation(s)
- Jennifer R Meyer
- University of Wisconsin, School of Medicine and Public Health, Madison, WI, USA
| | | | - Richard L Berg
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | | | - Jeremy Pomeroy
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | - Scott J Hebbring
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | - Robert M Haws
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA.,Marshfield Clinic Health System, Marshfield, Wisconsin, USA
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27
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Florea L, Caba L, Gorduza EV. Bardet-Biedl Syndrome-Multiple Kaleidoscope Images: Insight into Mechanisms of Genotype-Phenotype Correlations. Genes (Basel) 2021; 12:1353. [PMID: 34573333 DOI: 10.3390/genes12091353] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/22/2021] [Accepted: 08/27/2021] [Indexed: 01/04/2023] Open
Abstract
Bardet-Biedl Syndrome is a rare non-motile primary ciliopathy with multisystem involvement and autosomal recessive inheritance. The clinical picture is extremely polymorphic. The main clinical features are retinal cone-rod dystrophy, central obesity, postaxial polydactyly, cognitive impairment, hypogonadism and genitourinary abnormalities, and kidney disease. It is caused by various types of mutations, mainly in genes encoding BBSome proteins, chaperonins, and IFT complex. Variable expressivity and pleiotropy are correlated with the existence of multiple genes and variants modifiers. This review is focused on the phenomena of heterogeneity (locus, allelic, mutational, and clinical) in Bardet-Biedl Syndrome, its mechanisms, and importance in early diagnosis and proper management.
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28
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Pomeroy J, VanWormer JJ, Meilahn JR, Maki T, Murali HR, Haws RM. Sleep and physical activity patterns in adults and children with Bardet-Biedl syndrome. Orphanet J Rare Dis 2021; 16:276. [PMID: 34127036 PMCID: PMC8201861 DOI: 10.1186/s13023-021-01911-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 06/07/2021] [Indexed: 12/27/2022] Open
Abstract
Background Overweight and obesity are common features of the rare disease Bardet–Biedl syndrome (BBS). Sleep and physical activity are behaviors that might impact overweight and obesity and thus may play a key role in the health and well-being of people with BBS. Objectively-measured sleep and physical activity patterns in people with BBS are not well known. We evaluated objectively-measured sleep and physical activity patterns in the largest cohort to date of people with BBS. Results Short sleep duration, assessed using wrist-worn accelerometers, was common in both children and adults with BBS. Only 7 (10%) of adults and 6 (8%) of children met age-specific sleep duration recommendations. Most adults 64 (90%) achieved recommended sleep efficiency. The majority of children 26 (67%) age 6–12 years achieved recommended sleep efficiency, but among children age 13–18, only 18 (47%). In both adults and children, sleep duration was significantly negatively correlated with duration of prolonged sedentary time. In children age 6–12 sleep duration was also significantly related to total activity score, children with lower sleep duration had lower total activity scores. Conclusions Insufficient sleep duration is very common in people with BBS. Prolonged sedentary time and short sleep duration are both potentially important health-related behaviors to target for intervention in people with BBS. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01911-4.
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Affiliation(s)
- Jeremy Pomeroy
- Department of Clinical Research, Marshfield Clinic Research Institute, 1000 North Oak Ave, Marshfield, WI, 54449, USA.
| | - Jeffrey J VanWormer
- Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, WI, USA
| | - Jill R Meilahn
- Department of Physical Medicine, Marshfield Clinic Health System, Marshfield, WI, USA
| | - Tara Maki
- Physical Therapy Department, Marshfield Clinic Health System, Marshfield, WI, USA
| | - Hema R Murali
- Department of Pediatrics, Marshfield Clinic Health System, Marshfield, WI, USA
| | - Robert M Haws
- Department of Pediatrics, Marshfield Clinic Health System, Marshfield, WI, USA
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Pomeroy J, Krentz AD, Richardson JG, Berg RL, VanWormer JJ, Haws RM. Bardet-Biedl syndrome: Weight patterns and genetics in a rare obesity syndrome. Pediatr Obes 2021; 16:e12703. [PMID: 32700463 PMCID: PMC7816264 DOI: 10.1111/ijpo.12703] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare genetic disorder that severely inhibits primary cilia function. BBS is typified by obesity in adulthood, but pediatric weight patterns, and thus optimal periods of intervention, are poorly understood. OBJECTIVES To examine body mass differences by age, gender, and genotype in children and adolescents with BBS. METHODS We utilized the largest international registry of BBS phenotypes. Anthropometric and genetic data were obtained from medical records or participant/family interviews. Participants were stratified by age and sex categories. Genotype and obesity phenotype were investigated in a subset of participants with available data. RESULTS Height and weight measurements were available for 552 unique individuals with BBS. The majority of birth weights were in the normal range, but rates of overweight or obesity rapidly increased in early childhood, exceeding 90% after age 5. Weight z-scores in groups >2 years were above 2.0, while height z-scores approached 1.0, but were close to 0.0 in adolescents. Relative to those with the BBS10 genotype, the BBS1 cohort had a lower BMI z-score in the 2-5 and 6-11 age groups, with similar BMI z-scores thereafter. Children with biallelic loss of function (LOF) genetic variants had significantly higher BMI z-scores compared to missense variants. CONCLUSION Despite normal birth weight, most individuals with BBS experience rapid weight gain in early childhood, with high rates of overweight/obesity sustained through adolescence. Children with LOF variants are disproportionally affected. Our findings support the need for earlier recognition and initiation of weight management therapies in BBS.
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Affiliation(s)
- Jeremy Pomeroy
- Clinical Research CenterMarshfield Clinic Research InstituteMarshfieldWisconsinUSA
| | | | - Jesse G. Richardson
- Clinical Research CenterMarshfield Clinic Research InstituteMarshfieldWisconsinUSA
| | - Richard L. Berg
- Clinical Research CenterMarshfield Clinic Research InstituteMarshfieldWisconsinUSA
| | - Jeffrey J. VanWormer
- Clinical Research CenterMarshfield Clinic Research InstituteMarshfieldWisconsinUSA
| | - Robert M. Haws
- Clinical Research CenterMarshfield Clinic Research InstituteMarshfieldWisconsinUSA,Department of PediatricsMarshfield Clinic Health SystemMarshfieldWisconsinUSA
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