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Huang YN, Chiang SL, Huang JY, Lu WL, Bau DAT, Su PH, Wang CH. The Long-term Lung and Respiratory Outcomes of Acid Sphingomyelinase Deficiency: A 10- and 20-year Follow-up Study. In Vivo 2024; 38:437-444. [PMID: 38148059 PMCID: PMC10756436 DOI: 10.21873/invivo.13457] [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: 08/16/2023] [Revised: 09/17/2023] [Accepted: 09/18/2023] [Indexed: 12/28/2023]
Abstract
BACKGROUND/AIM Acid sphingomyelinase deficiency (ASMD) is a rare lysosomal storage disorder characterized by sphingomyelin accumulation causing progressive lung disease, respiratory failure, and death. PATIENTS AND METHODS This retrospective observational study used the TriNetX database of electronic health records for 15,108 patients with ASMD from 2000-2020. After exclusions, 8,980 individuals were followed for 10 or 20 years. Outcomes included incidence and prevalence of respiratory disorders. Associations of age, sex and race were assessed. RESULTS Nearly all respiratory outcomes increased significantly over 20 versus 10 years. Other respiratory disorders, specified respiratory disorders and secondary pulmonary hypertension exhibited the greatest increases, reflecting progressive lung damage in ASMD. While outcomes were poor overall, older age, male sex, and racial minority status associated with greater risks, indicating differences in disease progression or care. CONCLUSION This study confirms the progressive nature of ASMD and need for close monitoring and treatment of pulmonary complications to reduce long-term morbidity and mortality. Genetic testing enabling diagnosis even for milder, adult-onset forms is critical to optimize outcomes.
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Affiliation(s)
- Yu-Nan Huang
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan, R.O.C
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, R.O.C
| | - Shang-Lun Chiang
- Department of Medical Laboratory Science, College of Medical Science and Technology, I-Shou University, Kaohsiung, Taiwan, R.O.C
| | - Jing-Yang Huang
- Center for Health Data Science, Chung Shan Medical University Hospital, Taichung, Taiwan, R.O.C
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, R.O.C
| | - Wen-Li Lu
- Department of Clinical Pathology, Chi Mei Medical Center, Tainan, Taiwan, R.O.C
| | - DA-Tian Bau
- Terry Fox Cancer Research Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan, R.O.C
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan, R.O.C
| | - Pen-Hua Su
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan, R.O.C.;
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, R.O.C
| | - Chung-Hsing Wang
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan, R.O.C.;
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, R.O.C
- Division of Genetics and Metabolism, Children's Hospital of China Medical University, Taichung, Taiwan, R.O.C
- School of Medicine, China Medical University, Taichung, Taiwan, R.O.C
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Wang R, Qin Z, Huang L, Luo H, Peng H, Zhou X, Zhao Z, Liu M, Yang P, Shi T. SMPD1 expression profile and mutation landscape help decipher genotype-phenotype association and precision diagnosis for acid sphingomyelinase deficiency. Hereditas 2023; 160:11. [PMID: 36907956 PMCID: PMC10009935 DOI: 10.1186/s41065-023-00272-1] [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: 10/20/2022] [Accepted: 02/28/2023] [Indexed: 03/14/2023] Open
Abstract
BACKGROUND Acid sphingomyelinase deficiency (ASMD) disorder, also known as Niemann-Pick disease (NPD) is a rare genetic disease caused by mutations in SMPD1 gene, which encodes sphingomyelin phosphodiesterase (ASM). Except for liver and spleen enlargement and lung disease, two subtypes (Type A and B) of NDP have different onset times, survival times, ASM activities, and neurological abnormalities. To comprehensively explore NPD's genotype-phenotype association and pathophysiological characteristics, we collected 144 NPD cases with strict quality control through literature mining. RESULTS The difference in ASM activity can differentiate NPD type A from other subtypes, with the ratio of ASM activity to the reference values being lower in type A (threshold 0.045 (4.45%)). Severe variations, such as deletion and insertion, can cause complete loss of ASM function, leading to type A, whereas relatively mild missense mutations generally result in type B. Among reported mutations, the p.Arg3AlafsX76 mutation is highly prevalent in the Chinese population, and the p.R608del mutation is common in Mediterranean countries. The expression profiles of SMPD1 from GTEx and single-cell RNA sequencing data of multiple fetal tissues showed that high expressions of SMPD1 can be observed in the liver, spleen, and brain tissues of adults and hepatoblasts, hematopoietic stem cells, STC2_TLX1-positive cells, mesothelial cells of the spleen, vascular endothelial cells of the cerebellum and the cerebrum of fetuses, indicating that SMPD1 dysfunction is highly likely to have a significant effect on the function of those cell types during development and the clinicians need pay attention to these organs or tissues as well during diagnosis. In addition, we also predicted 21 new pathogenic mutations in the SMPD1 gene that potentially cause the NPD, signifying that more rare cases will be detected with those mutations in SMPD1. Finally, we also analysed the function of the NPD type A cells following the extracellular milieu. CONCLUSIONS Our study is the first to elucidate the effects of SMPD1 mutation on cell types and at the tissue level, which provides new insights into the genotype-phenotype association and can help in the precise diagnosis of NPD.
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Affiliation(s)
- Ruisong Wang
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
- Affiliated Hospital of Hunan University of Arts and Science (the Maternal and Child Health Hospital), Medical college, 3150 Dongting Ave., Changde, Hunan Province, People's Republic of China, 415000
| | - Ziyi Qin
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Long Huang
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Huiling Luo
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Han Peng
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Xinyu Zhou
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Zhixiang Zhao
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Mingyao Liu
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
- Changde Research Centre for Artificial Intelligence and Biomedicine, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China
| | - Pinhong Yang
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China.
- Changde Research Centre for Artificial Intelligence and Biomedicine, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China.
| | - Tieliu Shi
- College of Life and Environmental Sciences, Hunan University of Arts and Science, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China.
- Changde Research Centre for Artificial Intelligence and Biomedicine, 3150 Dongting Ave., Changde, 415000, Hunan Province, People's Republic of China.
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Cappellini MD, Motta I, Barbato A, Giuffrida G, Manna R, Carubbi F, Giona F. Similarities and differences between Gaucher disease and acid sphingomyelinase deficiency: An algorithm to support the diagnosis. Eur J Intern Med 2023; 108:81-84. [PMID: 36443133 DOI: 10.1016/j.ejim.2022.11.028] [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: 09/16/2022] [Revised: 11/14/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022]
Abstract
Lysosomal storage disorders are a group of inborn errors of metabolism due to defects in proteins crucial for lysosomal function. Gaucher disease is the most common autosomal recessive lysosomal storage disorder due to mutations in the GBA1 gene, resulting in the lysosomal deficiency of glucocerebrosidase activity. Gaucher disease is characterized by the toxic accumulation of glucosylceramide in the reticuloendothelial system. Acid sphingomyelinase deficiency (ASMD), previously known as Niemann Pick A/B disease, is also an autosomal recessive lysosomal storage disorder due to mutations in the SMPD1 gene, which result in acid sphingomyelinase deficiency and the accumulation of sphingomyelin in mononuclear phagocytic system and hepatocytes. The phenotypic expression of Gaucher disease type 1 (GD1), the most common type, and chronic visceral ASMD may overlap for several signs or symptoms. Splenomegaly is detectable in approximately 90% of the patients in both conditions; however, since GD1 is more frequent than ASMD, clinicians are more prone to suspect it, often neglecting the diagnosis of ASMD. Based on previous experience, a group of experts in the clinical and laboratory diagnosis, management, and treatment of lysosomal storage disorders developed an algorithm for both GD1 and ASMD to support physicians, including primary care providers, internists, and specialists (e.g., hepatologists, hematologists, and pulmonologists) to suspect and differentiate GD1 and ASMD and to provide the appropriate referral.
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Affiliation(s)
- Maria Domenica Cappellini
- Unit of Medicine and Metabolic Disease, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
| | - Irene Motta
- Unit of Medicine and Metabolic Disease, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - Antonio Barbato
- Department of Clinical Medicine and Surgery, Federico II University of Naples Medical School, Naples, Italy
| | - Gaetano Giuffrida
- Centro di riferimento regionale per la prevenzione, diagnosi e cura delle malattie rare, Division of Haematology, A.O.U Policlinico-S. Marco, Università degli studi di Catania, Catania, Italy
| | - Raffaele Manna
- Department of Internal Medicine, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - Francesca Carubbi
- Metabolic Medicine Unit, Azienda Ospedaliero Universitaria Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Fiorina Giona
- Department of Translational and Precision Medicine, Sapienza University of Rome, AOU Policlinico Umberto I, Rome, Italy
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Wasserstein M, Dionisi-Vici C, Giugliani R, Hwu WL, Lidove O, Lukacs Z, Mengel E, Mistry PK, Schuchman EH, McGovern M. Recommendations for clinical monitoring of patients with acid sphingomyelinase deficiency (ASMD). Mol Genet Metab 2019; 126:98-105. [PMID: 30514648 PMCID: PMC7249497 DOI: 10.1016/j.ymgme.2018.11.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/28/2018] [Accepted: 11/28/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND Acid sphingomyelinase deficiency (ASMD), a rare lysosomal storage disease, results from mutations in SMPD1, the gene encoding acid sphingomyelinase (ASM). As a result, sphingomyelin accumulates in multiple organs including spleen, liver, lung, bone marrow, lymph nodes, and in the most severe form, in the CNS and peripheral nerves. Clinical manifestations range from rapidly progressive and fatal infantile neurovisceral disease, to less rapidly progressing chronic neurovisceral and visceral forms that are associated with significant morbidity and shorter life span due to respiratory or liver disease. OBJECTIVES To provide a contemporary guide of clinical assessments for disease monitoring and symptom management across the spectrum of ASMD phenotypes. METHODS An international group of ASMD experts in various research and clinical fields used an evidence-informed consensus process to identify optimal assessments, interventions, and lifestyle modifications. RESULTS Clinical assessment strategies for major organ system involvement, including liver, spleen, cardiovascular, pulmonary, and neurological/developmental are described, as well as symptomatic treatments, interventions, and/or life style modifications that may lessen disease impact. CONCLUSIONS There is currently no disease-specific treatment for ASMD, although enzyme replacement therapy with a recombinant human ASM (olipudase alfa) is in clinical development. Current monitoring addresses symptoms and multisystem involvement. Recommended interventions and lifestyle modifications are designed to address morbidity and disease complications and improve patient quality of life. While infantile neurovisceral ASMD is uniformly fatal in early childhood, patients with chronic visceral and chronic neurovisceral ASMD require appropriate management throughout childhood and adulthood by an interdisciplinary clinical team.
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Affiliation(s)
- Melissa Wasserstein
- Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
| | | | - Roberto Giugliani
- Medical Genetics Service, HCPA, Department of Genetics, UFRGS, Porto Alegre, Brazil
| | | | - Olivier Lidove
- Groupe Hospitalier Diaconesses-Croix St Simon, Paris, France
| | - Zoltan Lukacs
- University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eugen Mengel
- University Medical Center, Johannes Gutenberg University, Mainz, Germany
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Kadali S, Madalasa T, Reddy GM, Naushad SM. Utility of amniotic fluid chitotriosidase in the prenatal diagnosis of lysosomal storage disorders. Clin Biochem 2018; 61:40-44. [PMID: 30205089 DOI: 10.1016/j.clinbiochem.2018.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 07/23/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Plasma chitotriosidase is a documented biomarker for certain lysosomal storage disorders. However, its clinical utility for prenatal samples is not elucidated yet. METHODS We have established Reference intervals for amniotic fluid chitotriosidase using control amniotic fluids (n = 47) and compared the activity with amniotic fluids affected by lysosomal storage disorders (n = 25). RESULTS The reference interval established was 0-6.76 nmol/h/ml. The amniotic fluids affected with LSDs exhibited elevation of chitotriosidase. The area under the curve (AUC) of receiver operating characteristic curve for affected vs. healthy was 0.987 indicating 98.6% accuracy of chitotriosidase in identifying pregnancies affected with LSDs. Among the different LSDs, Gaucher (202.00 ± 35.27 nmol/h/ml) and Niemann-pick A/B (60.33 ± 21.59 nmol/h/ml) showed very high levels of chitotriosidase. CONCLUSION Amniotic fluid chitotriosidase has the potential to serve as a diagnostic marker for lysosomal storage disorders, more specifically for Gaucher and Niemann-Pick A/B.
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MESH Headings
- Adult
- Amniocentesis
- Amniotic Fluid/enzymology
- Area Under Curve
- Biomarkers/metabolism
- Cells, Cultured
- Cohort Studies
- Exons
- Female
- Gaucher Disease/diagnosis
- Gaucher Disease/enzymology
- Gaucher Disease/genetics
- Gaucher Disease/pathology
- Gene Duplication
- Hexosaminidases/chemistry
- Hexosaminidases/genetics
- Hexosaminidases/metabolism
- Humans
- India
- Lysosomal Storage Diseases/diagnosis
- Lysosomal Storage Diseases/enzymology
- Lysosomal Storage Diseases/genetics
- Lysosomal Storage Diseases/pathology
- Mutation Rate
- Niemann-Pick Disease, Type A/diagnosis
- Niemann-Pick Disease, Type A/enzymology
- Niemann-Pick Disease, Type A/genetics
- Niemann-Pick Disease, Type A/pathology
- Niemann-Pick Disease, Type B/diagnosis
- Niemann-Pick Disease, Type B/enzymology
- Niemann-Pick Disease, Type B/genetics
- Niemann-Pick Disease, Type B/pathology
- Pregnancy
- Pregnancy Trimester, Second
- ROC Curve
- Reference Values
- Up-Regulation
- Young Adult
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6
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Faludi G, Gonda X, Döme P. [Adult psychiatric aspects of Niemann-Pick disease]. Neuropsychopharmacol Hung 2013; 15:95-103. [PMID: 23817360] [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] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Niemann-Pick disease (NPD) is a group of distinct rare disorders (i.e. NPD-A; NPD-B; NPD-C) - with autosomal recessive inheritance pattern - within the class of the inborn disorders of the sphingolipid metabolism (called sphingolipidoses). Since patients with NPD-A do not survive into adulthood and most patients with NPD-B are free from neuropsychiatric symptoms we discuss only briefly type-A and -B NPD and mainly constrict our review discussing the neuropsychiatric symptoms along with the pathomechanism and the treatment of NPD-C. NPD-C is clinically heterogeneous, with notable variations in age at onset, course and symptoms. Along with systemic signs, neurologic and psychiatric symptoms are quite frequent in NPD-C and in its adult form sometimes psychiatric symptoms are the first ones appearing. Unfortunately, the majority of clinicans (including adult psychiatrists and neurologists) are not aware of the symptom group characteristic to NPD-C so patients with this disorder are frequently misdiagnosed in the clinical practice. Since neuropsychiatric manifestations of NPD-C may be treated with a substrate reduction agent (miglustat) with greater awareness of the identification of neuropsychiatric symptoms in due course is the prerequisite of proper and early diagnosis and treatment.
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Affiliation(s)
- Gábor Faludi
- Klinikai és Kutatási Mentálhigiénés Osztály, Semmelweis Egyetem, Kútvölgyi Klinikai Tömb, Budapest, Hungary.
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Schuchman EH. The pathogenesis and treatment of acid sphingomyelinase-deficient Niemann-Pick disease. J Inherit Metab Dis 2007; 30:654-63. [PMID: 17632693 DOI: 10.1007/s10545-007-0632-9] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [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] [Received: 03/15/2007] [Revised: 05/11/2007] [Accepted: 05/14/2007] [Indexed: 01/17/2023]
Abstract
Patients with types A and B Niemann-Pick disease (NPD) have an inherited deficiency of acid sphingomyelinase (ASM) activity. The clinical spectrum of this disorder ranges from the infantile, neurological form that results in death by 3 years of age (type A NPD) to the non-neurological form (type B NPD) that is compatible with survival into adulthood. Intermediate cases also have been reported, and the disease is best thought of as a single entity with a spectrum of phenotypes. ASM deficiency is panethnic, but appears to be more frequent in individuals of Middle Eastern and North African descent. Current estimates of the disease incidence range from approximately 0.5 to 1 per 100,000 births. However, these approximations likely under estimate the true frequency of the disorder since they are based solely on cases referred to biochemical testing laboratories for enzymatic confirmation. The gene encoding ASM (SMPD1) has been studied extensively; it resides within an imprinted region on chromosome 11, and is preferentially expressed from the maternal chromosome. Over 100 SMPD1 mutations causing ASM-deficient NPD have been described, and some useful genotype-phenotype correlations have been made. Based on these findings, DNA-based carrier screening has been implemented in the Ashkenazi Jewish community. ASM 'knockout' mouse models also have been constructed and used to investigate disease pathogenesis and treatment. Based on these studies in the mouse model, an enzyme replacement therapy clinical trial has recently begun in adult patients with non-neurological ASM-deficient NPD.
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MESH Headings
- Animals
- Bone Marrow Transplantation
- Bronchoalveolar Lavage
- Disease Models, Animal
- Enzyme Inhibitors/therapeutic use
- Genetic Testing
- Genetic Therapy
- Genotype
- Humans
- Mice
- Mice, Knockout
- Mutation
- Niemann-Pick Disease, Type A/diagnosis
- Niemann-Pick Disease, Type A/enzymology
- Niemann-Pick Disease, Type A/ethnology
- Niemann-Pick Disease, Type A/genetics
- Niemann-Pick Disease, Type A/therapy
- Niemann-Pick Disease, Type B/diagnosis
- Niemann-Pick Disease, Type B/enzymology
- Niemann-Pick Disease, Type B/ethnology
- Niemann-Pick Disease, Type B/genetics
- Niemann-Pick Disease, Type B/therapy
- Phenotype
- Recombinant Proteins/therapeutic use
- Sphingomyelin Phosphodiesterase/deficiency
- Sphingomyelin Phosphodiesterase/genetics
- Sphingomyelin Phosphodiesterase/therapeutic use
- Splenectomy
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Affiliation(s)
- E H Schuchman
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, 1425 Madison Avenue, Room 14-20A, New York, NY 10029, USA.
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Ries M, Schaefer E, Lührs T, Mani L, Kuhn J, Vanier MT, Krummenauer F, Gal A, Beck M, Mengel E. Critical assessment of chitotriosidase analysis in the rational laboratory diagnosis of children with Gaucher disease and Niemann-Pick disease type A/B and C. J Inherit Metab Dis 2006; 29:647-52. [PMID: 16972172 DOI: 10.1007/s10545-006-0363-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 05/25/2006] [Accepted: 06/13/2006] [Indexed: 10/24/2022]
Abstract
Laboratory diagnosis of lysosomal storage disorders, especially sphingomyelinase deficiency (Niemann-Pick disease type A/B) and Niemann-Pick disease type C (NPC) can be challenging. We therefore aimed to analyse the feasibility of first-step screening with specific chitotriosidase cut-off values in children </= 10 years of age with visceral organomegaly (hepatomegaly, splenomegaly, or hepatosplenomegaly) in whom a storage disorder was suspected. We conducted a retrospective, cross-sectional, referral, single-centre study to assess diagnostic test properties in 106 individuals. Median chitotriosidase activity was 12 655 nmol/h per ml (interquartile range 4693-20982) in Gaucher disease (GD); 780 (465-1298) in SMD (sphingomyelinase deficiency); 925 (319-1215) in NPC and 50 (29-54) in patients with miscellaneous diseases. To restrict the differential diagnosis to GD, SMD or NPC, chitotriosidase activity above 200 nmol/h per ml had a sensitivity of 96%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 95%. For GD alone, chitotriosidase activity above 4000 nmol/h per ml had a sensitivity of 77%, specificity of 100%, PPV of 100% and NPV of 92%. Of the 44 patients analysed, 4.5% were homozygous and 36.4% heterozygous for chitotriosidase gene duplication. Adjusting for the chitotriosidase genotype, chitotriosidase activities were higher in GD type III than in GD type I. We conclude that, in the above setting, the degree of elevation of chitotriosidase activity can be applied to increase the likelihood of GD, SMD, or NPC and guide the choice of the appropriate confirmatory assay.
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Affiliation(s)
- Markus Ries
- Center for Lysosomal Storage Disorders, Children's Hospital, University of Mainz, Mainz, Germany.
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