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den Hollander B, Brands MM, Nijhuis IJM, Doude van Troostwijk LJAE, van Essen P, Hofsteenge GH, Koot BG, Müller AR, Tseng LA, Stroes ESG, van de Ven PM, Wiegman A, van Karnebeek CDM. Breaking the chains of lipoprotein lipase deficiency: A pediatric perspective on the efficacy and safety of Volanesorsen. Mol Genet Metab 2024; 142:108347. [PMID: 38401382 DOI: 10.1016/j.ymgme.2024.108347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/10/2024] [Accepted: 02/11/2024] [Indexed: 02/26/2024]
Abstract
RATIONALE Lipoprotein lipase (LPL) deficiency, a rare inherited metabolic disorder, is characterized by high triglyceride (TG) levels and life-threatening acute pancreatitis. Current treatment for pediatric patients involves a lifelong severely fat-restricted diet, posing adherence challenges. Volanesorsen, an EMA-approved RNA therapy for adults, effectively reduces TG levels by decreasing the production of apolipoprotein C-III. This 96-week observational open-label study explores Volanesorsen's safety and efficacy in a 13-year-old female with LPL deficiency. METHODS The patient, with a history of severe TG elevations, 53 hospital admissions, and life-threatening recurrent pancreatitis despite dietary restrictions, received weekly subcutaneous Volanesorsen injections. We designed a protocol for this investigator-initiated study, primarily focusing on changes in fasting TG levels and hospital admissions. RESULTS While the injections caused occasional pain and swelling, no other adverse events were observed. TG levels decreased during treatment, with more measurements below the pancreatitis risk threshold compared to pre-treatment. No hospital admissions occurred in the initial 14 months of treatment, contrasting with 21 admissions in the 96 weeks before. In the past 10 months, two pancreatitis episodes may have been linked to dietary noncompliance. Dietary restrictions were relaxed, increasing fat intake by 65% compared to baseline. While not fully reflected in the PedsQL, both parents and the patient narratively reported an improved quality of life. CONCLUSION This study demonstrates, for the first time, that Volanesorsen is tolerated in a pediatric patient with severe LPL deficiency and effectively lowers TG levels, preventing life-threatening complications. This warrants consideration for expanded access in this population.
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Affiliation(s)
- Bibiche den Hollander
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, the Netherlands; United for Metabolic Diseases, the Netherlands
| | - Marion M Brands
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, the Netherlands; United for Metabolic Diseases, the Netherlands
| | - Ilse J M Nijhuis
- Wilhelmina Hospital Assen, Department of Pediatrics, Europaweg-Zuid 1, Assen, the Netherlands
| | | | - Peter van Essen
- Radboud University Medical Center, Department of Pediatrics, Amalia Children's Hospital, Geert Grooteplein Zuid 10, Nijmegen, the Netherlands
| | - Geesje H Hofsteenge
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam UMC location University of Amsterdam, Department of Nutrition & Dietetics, Meibergdreef 9, Amsterdam, the Netherlands
| | - Bart G Koot
- Amsterdam UMC location University of Amsterdam, Department of Paediatric Gastroenterology and Nutrition, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands
| | - Annelieke R Müller
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, the Netherlands
| | - Laura A Tseng
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, the Netherlands; University Medical Center Rotterdam, Department of Pediatrics, Sophia Children's Hospital, Dr. Molewaterplein 40, Rotterdam, the Netherlands
| | - Erik S G Stroes
- Amsterdam UMC location University of Amsterdam, Department of Vascular Medicine, Meibergdraaf 9, Amsterdam, the Netherlands
| | - Peter M van de Ven
- University Medical Centre Utrecht, Department of Data Science and Biostatistics, Julius Center for Health Sciences and Primary Care, Heidelberglaan 100, Utrecht, Netherlands
| | - Albert Wiegman
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands
| | - Clara D M van Karnebeek
- Amsterdam UMC location University of Amsterdam, Department of Pediatrics, Emma Children's Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, the Netherlands; United for Metabolic Diseases, the Netherlands; Amsterdam UMC location University of Amsterdam, Department of Human Genetics, Amsterdam Reproduction and Development, Meibergdreef 9, Amsterdam, the Netherlands.
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Liu S, Wang Z, Zheng X, Zhang Y, Wei S, OuYang H, Liang J, Chen N, Zeng W, Jiang J. Case Report: Successful Management of a 29-Day-Old Infant With Severe Hyperlipidemia From a Novel Homozygous Variant of GPIHBP1 Gene. Front Pediatr 2022; 10:792574. [PMID: 35359903 PMCID: PMC8960264 DOI: 10.3389/fped.2022.792574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 02/03/2022] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Severe hyperlipidemia is characterized by markedly elevated blood triglyceride levels and severe early-onset cardiovascular diseases, pancreatitis, pancreatic necrosis or persistent multiple organ failure if left untreated. It is a rare autosomal recessive metabolic disorder originated from the variants of lipoprotein lipase gene, and previous studies have demonstrated that most cases with severe hyperlipidemia are closely related to the variants of some key genes for lipolysis, such as LPL, APOC2, APOA5, LMF1, and GPIHBP1. Meanwhile, other unidentified causes also exist and are equally worthy of attention. METHODS The 29-day-old infant was diagnosed with severe hyperlipidemia, registering a plasma triglyceride level as high as 25.46 mmol/L. Whole exome sequencing was conducted to explore the possible pathogenic gene variants for this patient. RESULTS The infant was put on a low-fat diet combined with pharmacological therapy, which was successful in restraining the level of serum triglyceride and total cholesterol to a low to medium range during the follow-ups. The patient was found to be a rare novel homozygous duplication variant-c.45_48dupGCGG (Pro17Alafs*22) in GPIHBP1 gene-leading to a frameshift which failed to form the canonical termination codon TGA. The mutant messenger RNA should presumably produce a peptide consisting of 16 amino acids at the N-terminus, with 21 novel amino acids on the heels of the wild-type protein. CONCLUSIONS Our study expands on the spectrum of GPIHBP1 variants and contributes to a more comprehensive understanding of the genetic diagnosis, genetic counseling, and multimodality therapy of families with severe hyperlipidemia. Our experience gained in this study is also contributory to a deeper insight into severe hyperlipidemia and highlights the importance of molecular genetic tests.
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Affiliation(s)
- Shu Liu
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Zhiqing Wang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xianhua Zheng
- Department of Clinical Laboratory, Guangdong Women and Children Hospital, Guangzhou, China
| | - Ye Zhang
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Sisi Wei
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Haimei OuYang
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jinqun Liang
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Nuan Chen
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Weihong Zeng
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jianhui Jiang
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Guangzhou, China
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Liu Y, Xu J, Tao W, Yu R, Zhang X. A Compound Heterozygous Mutation of Lipase Maturation Factor 1 is Responsible for Hypertriglyceridemia of a Patient. J Atheroscler Thromb 2018; 26:136-144. [PMID: 29910226 PMCID: PMC6365152 DOI: 10.5551/jat.44537] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
AIM Dyslipidemia is the most common lipid metabolism disorder in humans, and its etiology remains elusive. Hypertriglyceridemia (HTG) is a type of dyslipidemia that contributes to atherosclerosis and coronary heart disease. Previous studies have demonstrated that mutations in lipoprotein lipase (LPL), apolipoprotein CII (APOC2), apolipoprotein AV (APOA5), glycosylphosphatidylinositol anchored high-density lipoprotein-binding protein 1 (GPIHBP1), lipase maturation factor 1(LMF1), and glycerol-3 phosphate dehydrogenase 1 (GPD1) are responsible for HTG by using genomic microarrays and next-generation sequencing. The aim of this study was to identify genetic lesions in patients with HTG. METHOD Our study included a family of seven members from Jiangsu province across three generations. The proband was diagnosed with severe HTG, with a plasma triglyceride level of 38.70 mmol/L. Polymerase chain reaction (PCR) and Sanger sequencing were performed to explore the possible causative gene mutations for this patient. Furthermore, we measured the post-heparin LPL and hepatic lipase (HL) activities using an antiserum inhibition method. RESULTS A compound heterozygous mutation in the LMF1 gene (c.257C>T/p.P86L and c.1184C>T/p.T395I) was identified and co-segregated with the affected patient in this family. Both mutations were predicted to be deleterious by three bioinformatics programs (Polymorphism Phenotyping-2, Sorting Intolerant From Tolerant, and MutationTaster). The levels of the plasma post-heparin LPL and HL activities in the proband (57 and 177 mU/mL) were reduced to 24% and 75%, respectively, compared with those assayed in the control subject with normal plasma triglycerides. CONCLUSION A compound heterozygous mutation of LMF1 was identified in the presenting patient with severe HTG. These findings expand on the spectrum of LMF1 mutations and contribute to the genetic diagnosis and counseling of families with HTG.
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Affiliation(s)
- Yihui Liu
- Department of Neurology, Affiliated Hospital of Yangzhou University
| | - Jiang Xu
- Medical School of Yangzhou University
| | - Wanyun Tao
- Department of Biochemistry, School of Medicine, Case Western Reserve University
| | - Rong Yu
- Department of Anesthesiology, the Second XiangYa Hospital, Central South University
| | - Xinjiang Zhang
- Department of Neurology, Affiliated Hospital of Yangzhou University.,Medical School of Yangzhou University
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Buonuomo PS, Rabacchi C, Macchiaiolo M, Trenti C, Fasano T, Tarugi P, Bartuli A, Bertolini S, Calandra S. Incidental finding of severe hypertriglyceridemia in children. Role of multiple rare variants in genes affecting plasma triglyceride. J Clin Lipidol 2017; 11:1329-1337.e3. [PMID: 28951076 DOI: 10.1016/j.jacl.2017.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/18/2017] [Accepted: 08/25/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND The incidental finding of severe hypertriglyceridemia (HyperTG) in a child may suggest the diagnosis of familial chylomicronemia syndrome (FCS), a recessive disorder of the intravascular hydrolysis of triglyceride (TG)-rich lipoproteins. FCS may be due to pathogenic variants in lipoprotein lipase (LPL), as well as in other proteins, such as apolipoprotein C-II and apolipoprotein A-V (activators of LPL), GPIHBP1 (the molecular platform required for LPL activity on endothelial surface) and LMF1 (a factor required for intracellular formation of active LPL). OBJECTIVE Molecular characterization of 5 subjects in whom HyperTG was an incidental finding during infancy/childhood. METHODS We performed the parallel sequencing of 20 plasma TG-related genes. RESULTS Three children with severe HyperTG were found to be compound heterozygous for rare pathogenic LPL variants (2 nonsense, 3 missense, and 1 splicing variant). Another child was found to be homozygous for a nonsense variant of APOA5, which was also found in homozygous state in his father with longstanding HyperTG. The fifth patient with a less severe HyperTG was found to be heterozygous for a frameshift variant in LIPC resulting in a truncated Hepatic Lipase. In addition, 1 of the patients with LPL deficiency and the patient with APOA-V deficiency were also heterozygous carriers of a pathogenic variant in LIPC and LPL gene, respectively, whereas the patient with LIPC variant was also a carrier of a rare APOB missense variant. CONCLUSIONS Targeted parallel sequencing of TG-related genes is recommended to define the molecular defect in children presenting with an incidental finding of HyperTG.
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Affiliation(s)
| | - Claudio Rabacchi
- Department of Life Sciences, University of Modena & Reggio Emilia, Modena, Italy
| | - Marina Macchiaiolo
- Rare Diseases and Medical Genetics, Bambino Gesù Children Hospital, Rome, Italy
| | - Chiara Trenti
- Department of Internal Medicine, Lipid Clinic, IRCCS-Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Tommaso Fasano
- Clinical Chemistry and Endocrinology Laboratory, IRCCS-Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Patrizia Tarugi
- Department of Life Sciences, University of Modena & Reggio Emilia, Modena, Italy
| | - Andrea Bartuli
- Rare Diseases and Medical Genetics, Bambino Gesù Children Hospital, Rome, Italy
| | - Stefano Bertolini
- Department of Internal Medicine, University of Genova, Genova, Italy.
| | - Sebastiano Calandra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena & Reggio Emilia, Modena, Italy.
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Zhang Y, Zhou J, Zheng W, Lan Z, Huang Z, Yang Q, Liu C, Gao R, Zhang Y. Clinical, biochemical and molecular analysis of two infants with familial chylomicronemia syndrome. Lipids Health Dis 2016; 15:88. [PMID: 27153815 PMCID: PMC4859971 DOI: 10.1186/s12944-016-0254-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 04/20/2016] [Indexed: 11/23/2022] Open
Abstract
Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disease due mainly to inherited deficiencies in the proteins or enzymes involved in the clearance of triglycerides from circulation. It usually happens in late childhood and adolescence, which can have serious consequences if misdiagnosed or untreated. In the present study, we investigated two Chinese male babies (A and B), 30d and 48d in age, respectively, who have milky plasma. Clinical, biochemical, and radiological assessments were performed, while samples from the patients were referred for molecular diagnosis, including genetic testing and subsequent analysis of related genes. The fasting serum lipids of the two patients showed extreme lipid abnormalities. Through a low-lipid formula diet including skimmed milk and dietary advice, their plasma lipid levels were significantly lower and more stable at the time of hospital discharge. The genetic testing revealed compound heterozygote mutations in the lipoprotein lipase (LPL) gene for patient A and two known compound heterozygote LPL gene mutations for the patient B. FCS is the most dramatic example of severe hypertriglyceridemia. Early diagnosis and timely dietary intervention is very important for affected children.
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Affiliation(s)
- Yonghong Zhang
- Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Jing Zhou
- BGI-Shenzhen, Room 404 buiding No.11,Beishan industrial area, Beishan Road, Yantian District, Shenzhen, 518083, China
| | - Wenxin Zheng
- BGI-Shenzhen, Room 404 buiding No.11,Beishan industrial area, Beishan Road, Yantian District, Shenzhen, 518083, China
| | - Zhangzhang Lan
- BGI-Shenzhen, Room 404 buiding No.11,Beishan industrial area, Beishan Road, Yantian District, Shenzhen, 518083, China
| | - Zhiwei Huang
- BGI-Shenzhen, Room 404 buiding No.11,Beishan industrial area, Beishan Road, Yantian District, Shenzhen, 518083, China
| | - Qingnan Yang
- Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Chengbo Liu
- Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China
| | - Rui Gao
- BGI-Shenzhen, Room 404 buiding No.11,Beishan industrial area, Beishan Road, Yantian District, Shenzhen, 518083, China.
| | - Yongjun Zhang
- Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China. .,MOE and Shanghai Key Laboratory of Children's Environmental Health, Shanghai, China.
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Rabacchi C, Pisciotta L, Cefalù AB, Noto D, Fresa R, Tarugi P, Averna M, Bertolini S, Calandra S. Spectrum of mutations of the LPL gene identified in Italy in patients with severe hypertriglyceridemia. Atherosclerosis 2015; 241:79-86. [DOI: 10.1016/j.atherosclerosis.2015.04.815] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/24/2015] [Accepted: 04/26/2015] [Indexed: 12/20/2022]
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Buonuomo PS, Bartuli A, Rabacchi C, Bertolini S, Calandra S. A 3-day-old neonate with severe hypertriglyceridemia from novel mutations of the GPIHBP1 gene. J Clin Lipidol 2014; 9:265-70. [PMID: 25911085 DOI: 10.1016/j.jacl.2014.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/01/2014] [Accepted: 10/06/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Familial chylomicronemia is a genetic defect of the intravascular lipolysis of triglyceride (TG)-rich lipoproteins. Intravascular lipolysis involves the TG-hydrolase lipoprotein lipase (LPL) as well as other factors such as apolipoprotein CII and apolipoprotein AV (activators of LPL), GPIHBP1 (the molecular platform required for LPL activity on endothelial surface), and LMF1 (a factor required for intracellular formation of active LPL). METHODS We sequenced the familial chylomicronemia candidate genes in a neonate with chylomicronemia. RESULTS A 3-day-old newborn was found to have chylomicronemia (plasma TG 18.8 mmol/L, 1.667 mg/dL). The discontinuation of breastfeeding for 24 hours reduced plasma TG to 2.3 mmol/L (201 mg/dL), whereas its resumption induced a sharp TG increase (7.9 mmol/L, 690 mg/dL). The child was switched to a low-fat diet, which was effective in maintaining TG level below 3.5 mmol/L (294 mg/dL) during the first months of life. The child was found to be a compound heterozygous for 2 novel mutations in GPIHBP1 gene. The first mutation was a 9-bp deletion and 4-bp insertion in exon 2, causing a frameshift that abolished the canonical termination codon TGA. The predicted translation product of the mutant messenger RNA is a peptide that contains 51 amino acids of the N-terminal end of the wild-type protein followed by 252 novel amino acids. The second mutation was a nucleotide change (c.319T>C), causing an amino acid substitution p.(Ser107Pro) predicted in silico to be damaging. CONCLUSIONS GPIHBP1 mutations should be considered in neonates with chylomicronemia negative for mutations in LPL gene.
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Affiliation(s)
| | - Andrea Bartuli
- Rare Diseases and Medical Genetics, Bambino Gesù Children Hospital, Rome, Italy
| | - Claudio Rabacchi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Stefano Bertolini
- Department of Internal Medicine, University of Genova, Genova, Italy
| | - Sebastiano Calandra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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Pugni L, Riva E, Pietrasanta C, Rabacchi C, Bertolini S, Pederiva C, Mosca F, Calandra S. Severe hypertriglyceridemia in a newborn with monogenic lipoprotein lipase deficiency: an unconventional therapeutic approach with exchange transfusion. JIMD Rep 2013; 13:59-64. [PMID: 24142281 DOI: 10.1007/8904_2013_272] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/17/2013] [Accepted: 09/26/2013] [Indexed: 12/24/2022] Open
Abstract
Severe hypertriglyceridemia (sHTG) (plasma triglyceride level > 10 mmol/L) due to lipoprotein lipase (LPL) deficiency is a known risk factor for acute pancreatitis. A 23-day-old male with sHTG was admitted to the Neonatal Intensive Care Unit for plasmapheresis being at high risk for acute pancreatitis. Given the potential hazard of an extracorporeal technique in a very young infant, we decided to perform an exchange transfusion (ET), a procedure widely used by neonatologists and less invasive than plasmapheresis. ET led to a dramatic reduction in plasma triglyceride level, from 93.2 to 3.8 mmol/L at the end of the procedure, without adverse events. The subsequent administration of a special formula low in fat and high in medium-chain triglycerides was effective in keeping fasting plasma triglyceride level below 5.6 mmol/L during the first 5 months of life. The sequence of LPL gene revealed that the patient was apparently homozygous for a novel nucleotide deletion (c.840delG) in exon 6 leading to a premature termination codon (p.N281Mfs*23). However, family studies revealed that while the patient's mother was heterozygous for this mutation, the father was heterozygous for a novel deletion eliminating the whole LPL gene. The patient therefore turned out to be a compound heterozygous for two LPL gene mutations predicted to abolish LPL activity. This is the first case of sHTG treated with ET in a neonate reported in the literature. ET appears to be a safe procedure, alternative to plasmapheresis, to prevent acute pancreatitis in young infants with sHTG due to LPL deficiency.
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Affiliation(s)
- Lorenza Pugni
- NICU, Department of Clinical Sciences and Community Health, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Via Commenda 12, 20122, Milan, Italy,
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Surendran RP, Visser ME, Heemelaar S, Wang J, Peter J, Defesche JC, Kuivenhoven JA, Hosseini M, Péterfy M, Kastelein JJP, Johansen CT, Hegele RA, Stroes ESG, Dallinga-Thie GM. Mutations in LPL, APOC2, APOA5, GPIHBP1 and LMF1 in patients with severe hypertriglyceridaemia. J Intern Med 2012; 272:185-96. [PMID: 22239554 PMCID: PMC3940136 DOI: 10.1111/j.1365-2796.2012.02516.x] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVES The severe forms of hypertriglyceridaemia (HTG) are caused by mutations in genes that lead to the loss of function of lipoprotein lipase (LPL). In most patients with severe HTG (TG > 10 mmol L(-1) ), it is a challenge to define the underlying cause. We investigated the molecular basis of severe HTG in patients referred to the Lipid Clinic at the Academic Medical Center Amsterdam. METHODS The coding regions of LPL, APOC2, APOA5 and two novel genes, lipase maturation factor 1 (LMF1) and GPI-anchored high-density lipoprotein (HDL)-binding protein 1 (GPIHBP1), were sequenced in 86 patients with type 1 and type 5 HTG and 327 controls. RESULTS In 46 patients (54%), rare DNA sequence variants were identified, comprising variants in LPL (n = 19), APOC2 (n = 1), APOA5 (n = 2), GPIHBP1 (n = 3) and LMF1 (n = 8). In 22 patients (26%), only common variants in LPL (p.Asp36Asn, p.Asn318Ser and p.Ser474Ter) and APOA5 (p.Ser19Trp) could be identified, whereas no mutations were found in 18 patients (21%). In vitro validation revealed that the mutations in LMF1 were not associated with compromised LPL function. Consistent with this, five of the eight LMF1 variants were also found in controls and therefore cannot account for the observed phenotype. CONCLUSIONS The prevalence of mutations in LPL was 34% and mostly restricted to patients with type 1 HTG. Mutations in GPIHBP1 (n = 3), APOC2 (n = 1) and APOA5 (n = 2) were rare but the associated clinical phenotype was severe. Routine sequencing of candidate genes in severe HTG has improved our understanding of the molecular basis of this phenotype associated with acute pancreatitis and may help to guide future individualized therapeutic strategies.
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Affiliation(s)
- R P Surendran
- Department of Experimental Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
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