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Renard E, Thevenard-Berger A, Meyre D. Medical semiology of patients with monogenic obesity: A systematic review. Obes Rev 2024:e13797. [PMID: 38956946 DOI: 10.1111/obr.13797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 03/20/2024] [Accepted: 06/19/2024] [Indexed: 07/04/2024]
Abstract
Patients with monogenic obesity display numerous medical features on top of hyperphagic obesity, but no study to date has provided an exhaustive description of their semiology. Two reviewers independently conducted a systematic review of MEDLINE, Embase, and Web of Science Core Collection databases from inception to January 2022 to identify studies that described symptoms of patients carrying pathogenic mutations in at least one of eight monogenic obesity genes (ADCY3, LEP, LEPR, MC3R, MC4R, MRAP2, PCSK1, and POMC). Of 5207 identified references, 269 were deemed eligible after title and abstract screening, full-text reading, and risk of bias and quality assessment. Data extraction included mutation spectrum and mode of inheritance, clinical presentation (e.g., anthropometry, energy intake and eating behaviors, digestive function, puberty and fertility, cognitive features, infectious diseases, morphological characteristics, chronic respiratory disease, and cardiovascular disease), biological characteristics (metabolic profile, endocrinology, hematology), radiological features, and treatments. The review provides an exhaustive description of mandatory, non-mandatory, and unique symptoms in heterozygous and homozygous carriers of mutation in eight monogenic obesity genes. This information is critical to help clinicians to orient genetic testing in subsets of patients with suspected monogenic obesity and provide actionable treatments (e.g., recombinant leptin and MC4R agonist).
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Affiliation(s)
- Emeline Renard
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
- Department of Pediatrics, University Hospital of Nancy, Nancy, France
| | | | - David Meyre
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, and Nutrition, University Hospital of Nancy, Nancy, France
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
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Ong SG, Dehghan R, Dorajoo R, Liu JJ, Sng AA, Lee YS, Ooi DSQ. Novel Melanocortin-3 and -4 Receptor Functional Variants in Asian Children With Severe Obesity. J Clin Endocrinol Metab 2024; 109:e1249-e1259. [PMID: 37820740 DOI: 10.1210/clinem/dgad602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023]
Abstract
CONTEXT Genetic variants in melanocortin 3 receptor (MC3R) and melanocortin 4 receptor (MC4R) genes are strongly associated with childhood obesity. OBJECTIVE This study aims to identify and functionally characterize MC3R and MC4R variants in an Asian cohort of children with severe early-onset obesity. METHODS Whole-exome sequencing was performed to screen for MC3R and MC4R coding variants in 488 Asian children with severe early-onset obesity (body mass index for age ≥97th percentile). Functionality of the identified variants were determined via measurement of intracellular cyclic adenosine monophosphate (cAMP) concentrations and luciferase activity. RESULTS Four MC3R and 2 MC4R heterozygous nonsynonymous rare variants were detected. There were 3 novel variants: MC3R c.151G > C (p.Val51Leu), MC4R c.127C > A (p.Gln43Lys), and MC4R c.272T > G (p.Met91Arg), and 3 previously reported variants: MC3R c.127G > A (p.Glu43Lys), MC3R c.97G > A (p.Ala33Thr), and MC3R c.437T > A (p.Ile146Asn). Both MC3R c.127G > A (p.Glu43Lys) and MC4R c.272T > G (p.Met91Arg) variants demonstrated defective downstream cAMP signaling activity. The MC4R c.127C > A (p.Gln43Lys) variant showed reduced cAMP signaling activity at low substrate concentration but the signaling activity was restored at high substrate concentration. The MC3R c.151G > C (p.Val51Leu) variant did not show a significant reduction in cAMP signaling activity compared to wild-type (WT) MC3R. Coexpression studies of the WT and variant MC3R/MC4R showed that the heterozygous variants did not exhibit dominant negative effect. CONCLUSION Our functional assays demonstrated that MC3R c.127G > A (p.Glu43Lys) and MC4R c.272T > G (p.Met91Arg) variants might predispose individuals to early-onset obesity, and further studies are needed to establish the causative effect of these variants in the pathogenesis of obesity.
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Affiliation(s)
- Siong Gim Ong
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
| | - Roghayeh Dehghan
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
- Department of Genetics and Molecular Biology, School of Medicine, University of Medical Science, Isfahan 81746-73461, Iran
| | - Rajkumar Dorajoo
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
| | - Jian-Jun Liu
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Andrew Anjian Sng
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
| | - Yung Seng Lee
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
| | - Delicia Shu Qin Ooi
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
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Huang L, Deng X, Yang X, Tang Z, Fan S, Zhou Z, Tao M, Liu S. Cloning, distribution, and effects of growth regulation of MC3R and MC4R in red crucian carp ( Carassius auratus red var.). Front Endocrinol (Lausanne) 2024; 14:1310000. [PMID: 38322156 PMCID: PMC10846643 DOI: 10.3389/fendo.2023.1310000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/27/2023] [Indexed: 02/08/2024] Open
Abstract
Background Melanocortin-3 and -4 receptors (MC3R and MC4R), G protein-coupled receptors, play vital roles in the regulation of energy homeostasis. To understand the functions of mc3r and mc4r in the energy homeostasis of red crucian carp (Carassius auratus red var., RCC), we cloned mc3r and mc4r, analyzed the tissue expression and localization of the genes, and investigated the effects of knockout of mc3r (mc3r +/-) and mc4r (mc4r +/-) in RCC. Results The full-length cDNAs of RCC mc3r and mc4r were 1459 base pairs (bp) and 1894 bp, respectively. qRT-PCR indicated that mc3r and mc4r were profusely expressed in the brain, but lower expressed in the periphery tissues. ISH revealed that mc3r and mc4r were located in NPP, NPO, NAPv, NSC, NAT, NRL, NLTl, and NLTp of the brain, suggesting that mc3r and mc4r might regulate many physiological and behavioral aspects in RCC. To further verify the roles of mc3r and mc4r in energy homeostasis, the mc3r+/- and mc4r+/- fish were obtained by the CRISPR/Cas9 system. The average body weights, total lengths, body depths, and food intake of mc4r+/- fish were significantly higher than those of mc3r+/- and the normal wild-type (WT) fish, but there was no difference between the mc3r+/- and WT fish, indicating that the RCC phenotype and food intake were mainly influenced by mc4r but not mc3r. Interestingly, mc4r+/- fish displayed more visceral fat mass than mc3r+/- and WT fish, and mc3r+/- fish also exhibited slightly more visceral fat mass compared to WT. RNA-seq of the liver and muscle revealed that a large number of differentially expressed genes (DEGs) differed in WT vs. mc3r+/-, WT vs. mc4r+/-, and mc3r+/- vs. mc4r+/-, mainly related to lipid, glucose, and energy metabolism. The KEGG enrichment analysis revealed that DEGs were mainly enriched in pathways such as steroid biosynthesis, fatty acid metabolism, fatty acid biosynthesis, glycolysis/gluconeogenesis, wnt signaling pathway, PPAR signaling pathway, and MAPK signaling pathway, thereby affecting lipid accumulation and growth. Conclusion In conclusion, these results will assist in the further investigation of the molecular mechanisms in which MC3R and MC4R were involved in the regulation of energy homeostasis in fish.
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Affiliation(s)
| | | | | | | | | | | | - Min Tao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Shaojun Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
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Mohammed I, Haris B, Al-Barazenji T, Vasudeva D, Tomei S, Al Azwani I, Dauleh H, Shehzad S, Chirayath S, Mohamadsalih G, Petrovski G, Khalifa A, Love DR, Al-Shafai M, Hussain K. Understanding the Genetics of Early-Onset Obesity in a Cohort of Children From Qatar. J Clin Endocrinol Metab 2023; 108:3201-3213. [PMID: 37329217 PMCID: PMC10655519 DOI: 10.1210/clinem/dgad366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 06/10/2023] [Accepted: 06/14/2023] [Indexed: 06/18/2023]
Abstract
CONTEXT Monogenic obesity is a rare form of obesity due to pathogenic variants in genes implicated in the leptin-melanocortin signaling pathway and accounts for around 5% of severe early-onset obesity. Mutations in the genes encoding the MC4R, leptin, and leptin receptor are commonly reported in various populations to cause monogenic obesity. Determining the genetic cause has important clinical benefits as novel therapeutic interventions are now available for some forms of monogenic obesity. OBJECTIVE To unravel the genetic causes of early-onset obesity in the population of Qatar. METHODS In total, 243 patients with early-onset obesity (above the 95% percentile) and age of onset below 10 years were screened for monogenic obesity variants using a targeted gene panel, consisting of 52 obesity-related genes. RESULTS Thirty rare variants potentially associated with obesity were identified in 36 of 243 (14.8%) probands in 15 candidate genes (LEP, LEPR, POMC, MC3R, MC4R, MRAP2, SH2B1, BDNF, NTRK2, DYRK1B, SIM1, GNAS, ADCY3, RAI1, and BBS2). Twenty-three of the variants identified were novel to this study and the rest, 7 variants, were previously reported in literature. Variants in MC4R were the most common cause of obesity in our cohort (19%) and the c.485C>T p.T162I variant was the most frequent MC4R variant seen in 5 patients. CONCLUSION We identified likely pathogenic/pathogenic variants that seem to explain the phenotype of around 14.8% of our cases. Variants in the MC4R gene are the commonest cause of early-onset obesity in our population. Our study represents the largest monogenic obesity cohort in the Middle East and revealed novel obesity variants in this understudied population. Functional studies will be required to elucidate the molecular mechanism of their pathogenicity.
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Affiliation(s)
- Idris Mohammed
- College of Health & Life Sciences, Hamad Bin Khalifa University, PO Box 34110, Doha, Qatar
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Basma Haris
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Tara Al-Barazenji
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, PO Box 2713, Doha, Qatar
| | - Dhanya Vasudeva
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Sara Tomei
- Omics Core, Integrated Genomic Services, Research Branch, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Iman Al Azwani
- Omics Core, Integrated Genomic Services, Research Branch, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Hajar Dauleh
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Saira Shehzad
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Shiga Chirayath
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Ghassan Mohamadsalih
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Goran Petrovski
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Amel Khalifa
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Donald R Love
- Division of Genetic Pathology, Department of Pathology, Sidra Medicine, PO Box 26999, Doha, Qatar
| | - Mashael Al-Shafai
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, PO Box 2713, Doha, Qatar
- Biomedical Research Center, Qatar University, PO Box 2713, Doha, Qatar
| | - Khalid Hussain
- Division of Endocrinology, Department of Pediatric Medicine, Sidra Medicine, PO Box 26999, Doha, Qatar
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