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Li M, Gong S, Han X, Zhang S, Ren Q, Cai X, Luo Y, Zhou L, Zhang R, Liu W, Zhu Y, Zhou X, Sun Y, Li Y, Ma Y, Ji L. Genetic variants of ABCC8 and phenotypic features in Chinese early onset diabetes. J Diabetes 2021; 13:542-553. [PMID: 33300273 DOI: 10.1111/1753-0407.13144] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 09/13/2020] [Revised: 11/21/2020] [Accepted: 12/06/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND ABCC8 variants cause neonatal diabetes, maturity onset diabetes of the young (MODY), and hyperinsulinemic hypoglycemia because of activating or inactivating variants. In this study we used targeted exon sequencing to investigate genetic variants of ABCC8 and phenotypic features in Chinese patients with early onset diabetes (EOD). METHODS A cross-sectional study of 543 Chinese patients with EOD was recruited and the exons of them were conducted targeted sequencing. The pathogenicity of ABCC8 variants was defined according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology guideline. The phenotypes of patients owing to ABCC8 variants (ABCC8-MODY) were characterized. RESULTS Among the 543 participants, eight (1.5%) patients with ABCC8-MODY were identified. They harbored eight missense ABCC8 variants (p.R306C, p.E1326K, and p.R1379H, previously reported; p.R298C, p.F1176C, p.R1221W, p.K1358R, and p.I1404V) classified as likely pathogenic. Two family members with ABCC8-MODY were also confirmed. The average diagnosed age of the 10 patients was 26.8 ± 12.9 years. The majority of them had unsatisfactory glucose control, 80% of them had diabetic kidney disease, and neurological features were not observed. CONCLUSION Using targeted exon sequencing followed by pathogenicity analysis, we could be able to make genetic diagnoses for eight (1.5%) patients with ABCC8-MODY. The phenotype was variable with higher risk of diabetic microvascular complications. Genetic diagnosis is conducive for facilitating the personalized treatment of ABCC8-MODY.
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Affiliation(s)
- Meng Li
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Siqian Gong
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Xueyao Han
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Simin Zhang
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Qian Ren
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Xiaoling Cai
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Yingying Luo
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Lingli Zhou
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Rui Zhang
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Wei Liu
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Yu Zhu
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Xianghai Zhou
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Yanfang Sun
- Department of Internal Medicine, Hebei Province Sanhe Hospital, Langfang, China
| | - Yufeng Li
- Department of Endocrinology and Metabolism, Capital Medical University Pinggu Hospital, Beijing, China
| | - Yumin Ma
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
| | - Linong Ji
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China
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Sanchez Caballero L, Gorgogietas V, Arroyo MN, Igoillo-Esteve M. Molecular mechanisms of β-cell dysfunction and death in monogenic forms of diabetes. Int Rev Cell Mol Biol 2021; 359:139-256. [PMID: 33832649 DOI: 10.1016/bs.ircmb.2021.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Monogenetic forms of diabetes represent 1%-5% of all diabetes cases and are caused by mutations in a single gene. These mutations, that affect genes involved in pancreatic β-cell development, function and survival, or insulin regulation, may be dominant or recessive, inherited or de novo. Most patients with monogenic diabetes are very commonly misdiagnosed as having type 1 or type 2 diabetes. The severity of their symptoms depends on the nature of the mutation, the function of the affected gene and, in some cases, the influence of additional genetic or environmental factors that modulate severity and penetrance. In some patients, diabetes is accompanied by other syndromic features such as deafness, blindness, microcephaly, liver and intestinal defects, among others. The age of diabetes onset may also vary from neonatal until early adulthood manifestations. Since the different mutations result in diverse clinical presentations, patients usually need different treatments that range from just diet and exercise, to the requirement of exogenous insulin or other hypoglycemic drugs, e.g., sulfonylureas or glucagon-like peptide 1 analogs to control their glycemia. As a consequence, awareness and correct diagnosis are crucial for the proper management and treatment of monogenic diabetes patients. In this chapter, we describe mutations causing different monogenic forms of diabetes associated with inadequate pancreas development or impaired β-cell function and survival, and discuss the molecular mechanisms involved in β-cell demise.
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Affiliation(s)
- Laura Sanchez Caballero
- ULB Center for Diabetes Research (UCDR), Université Libre de Bruxelles, Brussels, Belgium. http://www.ucdr.be/
| | - Vyron Gorgogietas
- ULB Center for Diabetes Research (UCDR), Université Libre de Bruxelles, Brussels, Belgium. http://www.ucdr.be/
| | - Maria Nicol Arroyo
- ULB Center for Diabetes Research (UCDR), Université Libre de Bruxelles, Brussels, Belgium. http://www.ucdr.be/
| | - Mariana Igoillo-Esteve
- ULB Center for Diabetes Research (UCDR), Université Libre de Bruxelles, Brussels, Belgium. http://www.ucdr.be/.
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Giannopoulou EZ, Ovcarov O, De Franco E, Kassberger F, Nusser S, Otto MC, Denzer C, Wabitsch M. Transient neonatal diabetes due to a disease causing novel variant in the ATP-binding cassette subfamily C member 8 ( ABCC8) gene unmasks maturity-onset diabetes of the young (MODY) diabetes cases within a family. J Pediatr Endocrinol Metab 2021; 34:273-276. [PMID: 33185579 DOI: 10.1515/jpem-2020-0462] [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: 08/06/2020] [Accepted: 09/26/2020] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Neonatal diabetes mellitus (NDM) is a rare monogenic diabetes form, occurring mainly from ATP-binding cassette subfamily C member 8 (ABCC8) and KCNJ11 mutations. ABCC8 mutations have also been found to cause adult-onset diabetes. What is new?: •Novel ABCC8 mutation in an NDM case •Heterogeneous clinical presentation of diabetes and response to sulfonylurea therapy among family members with the same ABCC8 mutation. CASE PRESENTATION We report the case of a newborn with NDM and a heterozygous ABCC8 novel variant (c.3835G>A), successfully treated with sulfonylurea. The same ABCC8 variant was found in two other family members, already treated for type 2 diabetes. CONCLUSIONS This case demonstrates the variable phenotypic presentation of diabetes due to a novel ABCC8 mutation (c.3835G>A), ranging from transient NDM to adult-onset, insulin-demanding diabetes, among family members. Genetic testing in young individuals with a strong family history of diabetes, presenting with non-autoimmune diabetes is recommended as it can determine prognosis and treatment of affected family members.
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Affiliation(s)
- Eleni Z Giannopoulou
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Endocrinology and Diabetes, Ulm University, Ulm, Germany
| | - Olga Ovcarov
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Endocrinology and Diabetes, Ulm University, Ulm, Germany
| | - Elisa De Franco
- College of Medicine and Health, University of Exeter Medical School, Exeter, UK
| | - Fabian Kassberger
- Department of Pediatrics and Adolescent Medicine, Klinikum Göppingen, Göppingen, Germany
| | - Susanne Nusser
- Department of Pediatrics and Adolescent Medicine, Klinikum Göppingen, Göppingen, Germany
| | - Marie Celine Otto
- Department of Pediatrics and Adolescent Medicine, Klinikum Göppingen, Göppingen, Germany
| | - Christian Denzer
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Endocrinology and Diabetes, Ulm University, Ulm, Germany
| | - Martin Wabitsch
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Endocrinology and Diabetes, Ulm University, Ulm, Germany
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Aarthy R, Aston-Mourney K, Mikocka-Walus A, Radha V, Amutha A, Anjana RM, Unnikrishnan R, Mohan V. Clinical features, complications and treatment of rarer forms of maturity-onset diabetes of the young (MODY) - A review. J Diabetes Complications 2021; 35:107640. [PMID: 32763092 DOI: 10.1016/j.jdiacomp.2020.107640] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [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: 03/13/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 12/15/2022]
Abstract
Maturity onset diabetes of the young (MODY) is the most common form of monogenic diabetes and is currently believed to have 14 subtypes. While much is known about the common subtypes of MODY (MODY-1, 2, 3 and 5) little is known about its rare subtypes (MODY4, 6-14). With the advent of next-generation sequencing (NGS) there are several reports of the rarer subtypes of MODY emerging from across the world. Therefore, a greater understanding on these rarer subtypes is needed. A search strategy was created, and common databases were searched, and 51 articles finally selected. INS-(MODY10) and ABCC8-(MODY12) mutations were reported in relatively large numbers compared to the other rare subtypes. The clinical characteristics of the rare MODY subtypes exhibited heterogeneity between families reported with the same mutation. Obesity and diabetic ketoacidosis (DKA) were also reported among rarer MODY subtypes which presents as a challenge as these are not part of the original description of MODY by Tattersal and Fajans. The treatment modalities of the rarer subtypes included oral drugs, predominantly sulfonylureas, insulin but also diet alone. Newer drugs like DPP-4 and SGLT2 inhibitors have also been tried as new modes of treatment. The microvascular and macrovascular complications among the patients with various MODY subtypes are less commonly reported. Recently, there is a view that not all the 14 forms of 'MODY' are true MODY and the very existence of some of these rarer subtypes as MODY has been questioned. This scoping review aims to report on the clinical characteristics, treatment and complications of the rarer MODY subtypes published in the literature.
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Affiliation(s)
- Ramasamy Aarthy
- School of Medicine, Deakin University, Australia; Madras Diabetes Research Foundation, Chennai, India
| | | | | | | | | | - Ranjit Mohan Anjana
- Dr Mohan's Diabetes Specialities Centre, Madras Diabetes Research Foundation, Chennai, India
| | - Ranjit Unnikrishnan
- Dr Mohan's Diabetes Specialities Centre, Madras Diabetes Research Foundation, Chennai, India
| | - Viswanathan Mohan
- Dr Mohan's Diabetes Specialities Centre, Madras Diabetes Research Foundation, Chennai, India.
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Li M, Han X, Ji L. Clinical and Genetic Characteristics of ABCC8 Nonneonatal Diabetes Mellitus: A Systematic Review. J Diabetes Res 2021; 2021:9479268. [PMID: 34631896 PMCID: PMC8497126 DOI: 10.1155/2021/9479268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 08/11/2021] [Accepted: 08/16/2021] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES Diabetes mellitus (DM) is a major chronic metabolic disease in the world, and the prevalence has been increasing rapidly in recent years. The channel of KATP plays an important role in the regulation of insulin secretion. The variants in ABCC8 gene encoding the SUR1 subunit of KATP could cause a variety of phenotypes, including neonatal diabetes mellitus (ABCC8-NDM) and ABCC8-induced nonneonatal diabetes mellitus (ABCC8-NNDM). Since the features of ABCC8-NNDM have not been elucidated, this study is aimed at concluding the genetic features and clinical characteristics. METHODS We comprehensively reviewed the literature associated with ABCC8-NNDM in the following databases: MEDLINE, PubMed, and Web of Science to investigate the features of ABCC8-NNDM. RESULTS Based on a comprehensive literature search, we found that 87 probands with ABCC8-NNDM carried 71 ABCC8 genetic variant alleles, 24% of whom carried inactivating variants, 24% carried activating variants, and the remaining 52% carried activating or inactivating variants. Nine of these variants were confirmed to be activating or inactivating through functional studies, while four variants (p.R370S, p.E1506K, p.R1418H, and p.R1420H) were confirmed to be inactivating. The phenotypes of ABCC8-NNDM were variable and could also present with early hyperinsulinemia followed by reduced insulin secretion, progressing to diabetes later. They had a relatively high risk of microvascular complications and low prevalence of nervous disease, which is different from ABCC8-NDM. CONCLUSIONS Genetic testing is essential for proper diagnosis and appropriate treatment for patients with ABCC8-NNDM. And further studies are required to determine the complex mechanism of the variants of ABCC8-NNDM.
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Affiliation(s)
- Meng Li
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China 100044
| | - Xueyao Han
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China 100044
| | - Linong Ji
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Peking University Diabetes Center, Beijing, China 100044
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Lanes Iglesias S, Ares Blanco J, Bellido Castañeda V, Sánchez-Ragnarsson C, Menéndez-Torre E. Efectividad del tratamiento con sulfonilureas en paciente con mutación en el gen ABCC8 (MODY12). ENDOCRINOL DIAB NUTR 2020; 67:682-683. [DOI: 10.1016/j.endinu.2019.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/27/2019] [Accepted: 10/28/2019] [Indexed: 10/25/2022]
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Abstract
The ATP-sensitive potassium channel (KATP channel) couples blood levels of glucose to insulin secretion from pancreatic β-cells. KATP channel closure triggers a cascade of events that results in insulin release. Metabolically generated changes in the intracellular concentrations of adenosine nucleotides are integral to this regulation, with ATP and ADP closing the channel and MgATP and MgADP increasing channel activity. Activating mutations in the genes encoding either of the two types of KATP channel subunit (Kir6.2 and SUR1) result in neonatal diabetes mellitus, whereas loss-of-function mutations cause hyperinsulinaemic hypoglycaemia of infancy. Sulfonylurea and glinide drugs, which bind to SUR1, close the channel through a pathway independent of ATP and are now the primary therapy for neonatal diabetes mellitus caused by mutations in the genes encoding KATP channel subunits. Insight into the molecular details of drug and nucleotide regulation of channel activity has been illuminated by cryo-electron microscopy structures that reveal the atomic-level organization of the KATP channel complex. Here we review how these structures aid our understanding of how the various mutations in the genes encoding Kir6.2 (KCNJ11) and SUR1 (ABCC8) lead to a reduction in ATP inhibition and thereby neonatal diabetes mellitus. We also provide an update on known mutations and sulfonylurea therapy in neonatal diabetes mellitus.
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Affiliation(s)
- Tanadet Pipatpolkai
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Samuel Usher
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Phillip J Stansfeld
- Department of Biochemistry, University of Oxford, Oxford, UK
- School of Life Sciences, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
| | - Frances M Ashcroft
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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8
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Reilly F, Sanchez-Lechuga B, Clinton S, Crowe G, Burke M, Ng N, Colclough K, Byrne MM. Phenotype, genotype and glycaemic variability in people with activating mutations in the ABCC8 gene: response to appropriate therapy. Diabet Med 2020; 37:876-884. [PMID: 31562829 DOI: 10.1111/dme.14145] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/24/2019] [Indexed: 12/14/2022]
Abstract
AIMS To examine the phenotypic features of people identified with ABCC8-maturity-onset diabetes of the young (MODY) who were included in the adult 'Mater MODY' cohort and to establish their response to sulfonylurea therapy. METHODS Ten participants with activating ABCC8 mutations were phenotyped in detail. A 2-hour oral glucose tolerance test was performed to establish glycaemic tolerance, with glucose, insulin and C-peptide measurements taken at baseline and 30-min intervals. Insulin was discontinued and sulfonylurea therapy initiated after genetic diagnosis of ABCC8-MODY. A blinded continuous glucose monitoring sensor was used to establish glycaemic control on insulin vs a sulfonylurea. RESULTS The mean age at diagnosis of diabetes was 33.8 ± 11.1 years, with fasting glucose of 18.9 ± 11.5 mmol/l and a mean (range) HbA1c of 86 (51,126) mmol/mol [10.0 (6.8,13.7)%]. Following a genetic diagnosis of ABCC8-MODY three out of four participants discontinued insulin (mean duration 10.6 ± 1.69 years) and started sulfonylurea treatment. The mean (range) HbA1c prior to genetic diagnosis was 52 (43,74) mmol/mol (6.9%) and the post-treatment change was 44 (30,57) mmol/mol (6.2%; P=0.16). Retinopathy was the most common microvascular complication in this cohort, occurring in five out of 10 participants. CONCLUSIONS Low-dose sulfonylurea therapy resulted in stable glycaemic control and the elimination of hypoglycaemic episodes attributable to insulin therapy. The use of appropriate therapy at the early stages of diabetes may decrease the incidence of complications and reduce the risks of hypoglycaemia associated with insulin therapy.
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Affiliation(s)
- F Reilly
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - B Sanchez-Lechuga
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - S Clinton
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - G Crowe
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - M Burke
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - N Ng
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - K Colclough
- Department of Molecular Genetics, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - M M Byrne
- Department of Diabetes and Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
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Abstract
PURPOSE OF REVIEW Non-autoimmune monogenic diabetes (MD) in young people shows a broad spectrum of clinical presentations, which is largely explained by multiple genetic etiologies. This review discusses how the application of state-of-the-art genomics research to precision diagnosis of MD, particularly the various subtypes of maturity-onset diabetes of the young (MODY), has increasingly informed diabetes precision medicine and patient care throughout life. RECENT FINDINGS Due to extended genetic and clinical heterogeneity of MODY, diagnosis approaches based on next-generation sequencing have been worthwhile to better ascribe a specific subtype to each patient with young-onset diabetes. This guides the best appropriate treatment and clinical follow-up. Early etiological diagnosis of MD and individualized treatment are essential for achieving metabolic targets and avoiding long-term diabetes complications, as well as for drastically decreasing the financial and societal burden of diabetes-related healthcare. Genomic medicine-based practices help to optimize long-term clinical follow-up and patient care management.
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Affiliation(s)
- Martine Vaxillaire
- Univ. Lille, CNRS, CHU Lille, Institut Pasteur de Lille, UMR 8199 - European Genomic Institute for Diabetes (EGID), University Lille, F-59000, Lille, France.
- Faculty of Medicine, CNRS UMR 8199, 1 Place de Verdun, F-59045, Lille, France.
| | - Philippe Froguel
- Univ. Lille, CNRS, CHU Lille, Institut Pasteur de Lille, UMR 8199 - European Genomic Institute for Diabetes (EGID), University Lille, F-59000, Lille, France
- Department of Medicine, Section of Genomics of Common Disease, Imperial College London, London, UK
| | - Amélie Bonnefond
- Univ. Lille, CNRS, CHU Lille, Institut Pasteur de Lille, UMR 8199 - European Genomic Institute for Diabetes (EGID), University Lille, F-59000, Lille, France
- Department of Medicine, Section of Genomics of Common Disease, Imperial College London, London, UK
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Balamurugan K, Kavitha B, Yang Z, Mohan V, Radha V, Shyng SL. Functional characterization of activating mutations in the sulfonylurea receptor 1 (ABCC8) causing neonatal diabetes mellitus in Asian Indian children. Pediatr Diabetes 2019; 20:397-407. [PMID: 30861254 DOI: 10.1111/pedi.12843] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [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: 11/18/2018] [Revised: 01/28/2019] [Accepted: 02/24/2019] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Gain-of-function of ATP-sensitive K+ (KATP ) channels because of mutations in the genes encoding SUR1 (ABCC8) or Kir6.2 (KCNJ11) is a major cause of neonatal diabetes mellitus (NDM). Our aim is to determine molecular defects in KATP channels caused by ABCC8 mutations in Asian Indian children with NDM by in vitro functional studies. METHODS Wild-type (WT; NM_000352.4) or mutant sulfonylurea receptor 1 (SUR1) and Kir6.2 were co-expressed in COSm6 cells. Biogenesis efficiency and surface expression of mutant channels were assessed by immunoblotting and immunostaining. The response of mutant channels to cytoplasmic ATP and ADP was assessed by inside-out patch-clamp recordings. The response of mutant channels to known KATP inhibitors in intact cells were determined by 86 Rb efflux assays. RESULTS Five SUR1 missense mutations, D212Y, P254S, R653Q, R992C, and Q1224H, were studied and showed increased activity in MgATP/MgADP. Two of the mutants, D212Y and P254S, also showed reduced response to ATP4- inhibition, as well as markedly reduced surface expression. Moreover, all five mutants were inhibited by the KATP channel inhibitors glibenclamide and carbamazepine. CONCLUSIONS The study shows the mechanisms by which five SUR1 mutations identified in Asian Indian NDM patients affect KATP channel function to cause the disease. The reduced ATP4- sensitivity caused by the D212Y and P254S mutations in the L0 of SUR1 provides novel insight into the role of L0 in channel inhibition by ATP. The results also explain why sulfonylurea therapy is effective in two patients and inform how it should be effective for the other three patients.
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Affiliation(s)
- Kandasamy Balamurugan
- Department of Molecular Genetics, Madras Diabetes Research Foundation, ICMR Advanced Centre for Genomics of Type 2 Diabetes and Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, IDF Centre of Education, Chennai, India.,Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon
| | - Babu Kavitha
- Department of Molecular Genetics, Madras Diabetes Research Foundation, ICMR Advanced Centre for Genomics of Type 2 Diabetes and Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, IDF Centre of Education, Chennai, India
| | - Zhongying Yang
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon
| | - Viswanathan Mohan
- Department of Molecular Genetics, Madras Diabetes Research Foundation, ICMR Advanced Centre for Genomics of Type 2 Diabetes and Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, IDF Centre of Education, Chennai, India
| | - Venkatesan Radha
- Department of Molecular Genetics, Madras Diabetes Research Foundation, ICMR Advanced Centre for Genomics of Type 2 Diabetes and Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, IDF Centre of Education, Chennai, India
| | - Show-Ling Shyng
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon
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Koufakis T, Sertedaki A, Tatsi EB, Trakatelli CM, Karras SN, Manthou E, Kanaka-Gantenbein C, Kotsa K. First Report of Diabetes Phenotype due to a Loss-of-Function ABCC8 Mutation Previously Known to Cause Congenital Hyperinsulinism. Case Rep Genet 2019; 2019:3654618. [PMID: 31110826 DOI: 10.1155/2019/3654618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 03/25/2019] [Accepted: 03/31/2019] [Indexed: 12/19/2022] Open
Abstract
Monogenic Diabetes is relatively rare, representing only 1-2% of total diabetes cases; nevertheless, it is often misdiagnosed primarily as type 1 diabetes, leading to unnecessary insulin therapy and delayed recognition of affected family members. In the present article, we describe a case of a young, male patient who presented with hyperglycemia in the absence of ketosis and following genetic testing; he proved to harbor the loss-of-function p.Arg1353His (c.4058G>A) mutation in the ABCC8 gene, inherited from his mother. This mutation has been previously described in patients with Congenital Hyperinsulinism. Furthermore, different mutations in the ABCC8 gene have been linked with MODY 12, type 2, and gestational diabetes; however, to the best of our knowledge, this is the first report that associates this specific mutation with diabetes phenotype. ABCC8-related diabetes is characterized by remarkable heterogeneity in terms of clinical presentation and therapeutic approach. Early diagnosis and individualized treatment are essential to achieving metabolic targets and avoiding long-term diabetes complications.
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