1
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Yi M, Shen P, Zhang H. Delayed diagnosis of mild mucopolysaccharidosis type IVA. BMC Med Genomics 2024; 17:151. [PMID: 38831290 PMCID: PMC11145893 DOI: 10.1186/s12920-024-01910-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/14/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by biallelic variants in the N-acetylgalactosamine-6-sulfatase (GALNS) gene and is characterized by progressive and multi-system involvements, dominantly with skeletal deformities. A mild form of MPS IVA often presents with atypical symptoms and can go unrecognized for years. METHODS The diagnosis of MPS IVA was confirmed via GALNS enzyme activity testing in leukocytes. Clinical features were collected. Molecular analysis was performed by next generation sequence and Sanger sequencing of the GALNS gene. The pathogenicity of the deep intron variant was verified by mRNA analyses. RESULTS Thirteen patients with mild MPS IVA from six families were included. All probands first visit pediatric orthopedists and it took 5.6 years to be diagnosed after the disease onset. The most common symptoms in our series were waddling gait (85%), short neck (69%) and flat feet (62%). Radiologic findings indicated skeletal abnormalities in all patients, especially modification of the vertebral bodies (100%) and acetabular and femoral head dysplasia (100%). Five novel GALNS variants, including c.121-2_121-1insTTTGCTGGCATATGCA, E2 deletion, c.569 A > G, c.898 + 2 T > A, and c.1139 + 2 T > C, were identified. The most common variant, a deep intron variant NM_000512.5: c.121-210 C > T (NM_001323544.2: c.129 C > T, p.G43G), was revealed to result in an 11 bp deletion (c.128_138delGCGATGCTGAG, p.Gly43Aspfs*5) on GALNS mRNA in the GALNS transcript of NM_001323544.2. CONCLUSIONS This study provides significant insights into the clinical features and molecular characteristics that contribute to the early diagnosis of mild MPS IVA. On the basis of our cohort, orthopedists need to be able to recognize signs and symptoms of mild MPS IVA as well as the molecular and biochemical diagnosis so that an early diagnosis and treatment can be instituted.
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Affiliation(s)
- Mengni Yi
- Pediatric Endocrinology and Genetics, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665 #, Shanghai, 200092, PR China
| | - Pinquan Shen
- Department of Pediatric Orthopaedics, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665 #, Shanghai, 200092, PR China.
| | - Huiwen Zhang
- Pediatric Endocrinology and Genetics, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665 #, Shanghai, 200092, PR China.
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2
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Bloch-Zupan A, Rey T, Jimenez-Armijo A, Kawczynski M, Kharouf N, Dure-Molla MDL, Noirrit E, Hernandez M, Joseph-Beaudin C, Lopez S, Tardieu C, Thivichon-Prince B, Dostalova T, Macek M, Alloussi ME, Qebibo L, Morkmued S, Pungchanchaikul P, Orellana BU, Manière MC, Gérard B, Bugueno IM, Laugel-Haushalter V. Amelogenesis imperfecta: Next-generation sequencing sheds light on Witkop's classification. Front Physiol 2023; 14:1130175. [PMID: 37228816 PMCID: PMC10205041 DOI: 10.3389/fphys.2023.1130175] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/06/2023] [Indexed: 05/27/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of genetic rare diseases disrupting enamel development (Smith et al., Front Physiol, 2017a, 8, 333). The clinical enamel phenotypes can be described as hypoplastic, hypomineralized or hypomature and serve as a basis, together with the mode of inheritance, to Witkop's classification (Witkop, J Oral Pathol, 1988, 17, 547-553). AI can be described in isolation or associated with others symptoms in syndromes. Its occurrence was estimated to range from 1/700 to 1/14,000. More than 70 genes have currently been identified as causative. Objectives: We analyzed using next-generation sequencing (NGS) a heterogeneous cohort of AI patients in order to determine the molecular etiology of AI and to improve diagnosis and disease management. Methods: Individuals presenting with so called "isolated" or syndromic AI were enrolled and examined at the Reference Centre for Rare Oral and Dental Diseases (O-Rares) using D4/phenodent protocol (www.phenodent.org). Families gave written informed consents for both phenotyping and molecular analysis and diagnosis using a dedicated NGS panel named GenoDENT. This panel explores currently simultaneously 567 genes. The study is registered under NCT01746121 and NCT02397824 (https://clinicaltrials.gov/). Results: GenoDENT obtained a 60% diagnostic rate. We reported genetics results for 221 persons divided between 115 AI index cases and their 106 associated relatives from a total of 111 families. From this index cohort, 73% were diagnosed with non-syndromic amelogenesis imperfecta and 27% with syndromic amelogenesis imperfecta. Each individual was classified according to the AI phenotype. Type I hypoplastic AI represented 61 individuals (53%), Type II hypomature AI affected 31 individuals (27%), Type III hypomineralized AI was diagnosed in 18 individuals (16%) and Type IV hypoplastic-hypomature AI with taurodontism concerned 5 individuals (4%). We validated the genetic diagnosis, with class 4 (likely pathogenic) or class 5 (pathogenic) variants, for 81% of the cohort, and identified candidate variants (variant of uncertain significance or VUS) for 19% of index cases. Among the 151 sequenced variants, 47 are newly reported and classified as class 4 or 5. The most frequently discovered genotypes were associated with MMP20 and FAM83H for isolated AI. FAM20A and LTBP3 genes were the most frequent genes identified for syndromic AI. Patients negative to the panel were resolved with exome sequencing elucidating for example the gene involved ie ACP4 or digenic inheritance. Conclusion: NGS GenoDENT panel is a validated and cost-efficient technique offering new perspectives to understand underlying molecular mechanisms of AI. Discovering variants in genes involved in syndromic AI (CNNM4, WDR72, FAM20A … ) transformed patient overall care. Unravelling the genetic basis of AI sheds light on Witkop's AI classification.
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Affiliation(s)
- Agnes Bloch-Zupan
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Université de Strasbourg, Institut d’études avancées (USIAS), Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Eastman Dental Institute, University College London, London, United Kingdom
| | - Tristan Rey
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
| | - Alexandra Jimenez-Armijo
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
| | - Marzena Kawczynski
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
| | - Naji Kharouf
- Université de Strasbourg, Laboratoire de Biomatériaux et Bioingénierie, Inserm UMR_S 1121, Strasbourg, France
| | | | - Muriel de La Dure-Molla
- Rothschild Hospital, Public Assistance-Paris Hospitals (AP-HP), Reference Center for Rare Oral and Den-tal Diseases (O-Rares), Paris, France
| | - Emmanuelle Noirrit
- Centre Hospitalier Universitaire (CHU) Rangueil, Toulouse, Competence Center for Rare Oral and Den-tal Diseases, Toulouse, France
| | - Magali Hernandez
- Centre Hospitalier Régional Universitaire de Nancy, Université de Lorraine, Competence Center for Rare Oral and Dental Diseases, Nancy, France
| | - Clara Joseph-Beaudin
- Centre Hospitalier Universitaire de Nice, Competence Center for Rare Oral and Dental Diseases, Nice, France
| | - Serena Lopez
- Centre Hospitalier Universitaire de Nantes, Competence Center for Rare Oral and Dental Diseases, Nantes, France
| | - Corinne Tardieu
- APHM, Hôpitaux Universitaires de Marseille, Hôpital Timone, Competence Center for Rare Oral and Dental Diseases, Marseille, France
| | - Béatrice Thivichon-Prince
- Centre Hospitalier Universitaire de Lyon, Competence Center for Rare Oral and Dental Diseases, Lyon, France
| | | | - Tatjana Dostalova
- Department of Stomatology (TD) and Department of Biology and Medical Genetics (MM) Charles University 2nd Faculty of Medicine and Motol University Hospital, Prague, Czechia
| | - Milan Macek
- Department of Stomatology (TD) and Department of Biology and Medical Genetics (MM) Charles University 2nd Faculty of Medicine and Motol University Hospital, Prague, Czechia
| | | | - Mustapha El Alloussi
- Faculty of Dentistry, International University of Rabat, CReSS Centre de recherche en Sciences de la Santé, Rabat, Morocco
| | - Leila Qebibo
- Unité de génétique médicale et d’oncogénétique, CHU Hassan II, Fes, Morocco
| | | | | | - Blanca Urzúa Orellana
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Marie-Cécile Manière
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
| | - Bénédicte Gérard
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
| | - Isaac Maximiliano Bugueno
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
| | - Virginie Laugel-Haushalter
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
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3
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Ghafoor S, Silveira KDC, Qamar R, Azam M, Kannu P. Exome Sequencing Identifies a Biallelic GALNS Variant (p.Asp233Asn) Causing Mucopolysaccharidosis Type IVA in a Pakistani Consanguineous Family. Genes (Basel) 2022; 13:genes13101743. [PMID: 36292628 PMCID: PMC9602411 DOI: 10.3390/genes13101743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 01/02/2023] Open
Abstract
Mucopolysaccharidoses (MPS) type IVA is a lysosomal storage disease that mainly affects the skeletal system and is caused by a deficiency of the enzyme N-acetylgalactosamine-6-sulfatase (GALNS). The condition can mistakenly be diagnosed as a primary skeletal dysplasia such as spondylo-epiphyseal dysplasia, which shares many similar phenotypic features. Here, we utilised whole exome sequencing to make the diagnosis of MPS IVA in a resource poor country. We report for the first time the identification of a biallelic GALNS missense variant (c.697G>A, p.Asp233Asn) in the Pakistani population and highlight the potential contribution that academic institutions can make in rare disease diagnosis in the absence of a developed clinical genetic service.
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Affiliation(s)
- Saima Ghafoor
- Translational Genomics Laboratory, COMSATS University Islamabad, Islamabad 45550, Pakistan
| | | | - Raheel Qamar
- Pakistan Academy of Sciences, Islamabad 44000, Pakistan
- Science and Technology Sector, ICESCO, Rabat 10104, Morocco
| | - Maleeha Azam
- Translational Genomics Laboratory, COMSATS University Islamabad, Islamabad 45550, Pakistan
- Correspondence: or (M.A.); (P.K.); Tel.: +92-(51)-9235033 (M.A.); +1-(780)-492-9044 (P.K.)
| | - Peter Kannu
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Correspondence: or (M.A.); (P.K.); Tel.: +92-(51)-9235033 (M.A.); +1-(780)-492-9044 (P.K.)
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4
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Selvam P, Jain A, Abbott J, Ahuja AS, Cheema A, Bruno KA, Atwal H, Forghani I, Caulfield T, Atwal PS. Molecular Modeling and Phenotypic Description of a Patient with a Novel Exonic Deletion of GALNS with Resultant Morquio Syndrome with Two Successful Pregnancies. Mol Syndromol 2022; 13:282-289. [PMID: 36158053 PMCID: PMC9421684 DOI: 10.1159/000519326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/30/2021] [Indexed: 01/03/2023] Open
Abstract
In this report, we describe phenotypic features of a patient with mucopolysaccharidosis type IVA (Morquio syndrome) harboring a novel exon 1 deletion in GALNS with enzymatic confirmation consistent with Morquio syndrome. To our knowledge, this is the first reported case of this variant. Additionally, we protein modelled wild-type GALNS and the pathogenic variant with an exon 1 deletion for comparative analysis using statistical mechanics methods described herein. We demonstrate that, even when the protein is translated, the mutation would affect protein stability and function via homodimer interaction modifications. Lastly, given the patient's 2 successful pregnancies, data about the management of pregnancies in mucopolysaccharidoses are reviewed, and we discuss the management of pregnancy in patients with Morquio syndrome.
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Affiliation(s)
| | | | | | - Abhimanyu S. Ahuja
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida, USA
| | | | | | | | - Irman Forghani
- Dr. John T. Macdonald Foundation Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, USA
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5
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Sohn YB, Rogers C, Stallworth J, Cooley Coleman JA, Buch L, Jozwiak E, Johnson JA, Wood T, Harmatz P, Pollard L, Louie RJ. RNA analysis of the GALNS transcript reveals novel pathogenic mechanisms associated with Morquio syndrome A. Mol Genet Metab Rep 2022; 31:100875. [PMID: 35782621 PMCID: PMC9248232 DOI: 10.1016/j.ymgmr.2022.100875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 11/29/2022] Open
Abstract
Morquio syndrome A (Mucopolysaccharidosis IVA, MPS IVA) is an autosomal recessive lysosomal storage disorder caused by deficiency of N-acetyl-galactosamine-6-sulfatase (GALNS) which catabolizes the glycosaminoglycans (GAG), keratan sulfate and chondroitin-6-sulfate. Homozygous or compound heterozygous pathogenic variants in the GALNS result in the deficiency of the enzyme and consequent GAG accumulations. DNA sequence and copy number analysis of the GALNS coding region fails to identify biallelic causative pathogenic variants in up to 15% of patients with Morquio syndrome A. RNA transcript analysis was performed to identify pathogenic alterations in two unrelated families with Morquio syndrome A in whom a single heterozygous or no pathogenic alteration was detected by standard analysis of the GALNS gene. RNA sequencing and quantitative expression analysis identified the overabundance of an aberrant GALNS transcript isoform and a reduction of the clinically relevant isoform (NM_000512.4) in the Morquio syndrome A patients from both families. The aberrant isoform (ENST00000568613.1) was produced by alternative splicing and contained intronic sequence that was likely a cryptic exon predicted to result in a reading frame shift and generation of a premature termination codon. These findings indicated that the aberrant splicing is likely the novel molecular defect in our patients. RNA transcript analysis could be useful to identify pathogenic alterations and increase the yield of molecular diagnosis in patients with Morquio syndrome A whose genetic variants are not found by standard sequencing or gene dosage analysis.
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Affiliation(s)
- Young Bae Sohn
- Department of Medical Genetics, Ajou University Hospital, Ajou University School of Medicine, Suwon, Republic of Korea
- Corresponding author at: Department of Medical Genetics, Ajou University Hospital, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon 16499, Republic of Korea.
| | | | | | | | - Laura Buch
- Greenwood Genetic Center, Greenwood, SC, USA
| | - Erin Jozwiak
- UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA
| | - Jo Ann Johnson
- UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA
| | - Tim Wood
- Section of Genetics and Metabolism, University of Colorado/Children's Hospital of Colorado, Aurora, CO, USA
| | - Paul Harmatz
- UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA
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6
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Keegan NP, Wilton SD, Fletcher S. Analysis of Pathogenic Pseudoexons Reveals Novel Mechanisms Driving Cryptic Splicing. Front Genet 2022; 12:806946. [PMID: 35140743 PMCID: PMC8819188 DOI: 10.3389/fgene.2021.806946] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/09/2021] [Indexed: 12/16/2022] Open
Abstract
Understanding pre-mRNA splicing is crucial to accurately diagnosing and treating genetic diseases. However, mutations that alter splicing can exert highly diverse effects. Of all the known types of splicing mutations, perhaps the rarest and most difficult to predict are those that activate pseudoexons, sometimes also called cryptic exons. Unlike other splicing mutations that either destroy or redirect existing splice events, pseudoexon mutations appear to create entirely new exons within introns. Since exon definition in vertebrates requires coordinated arrangements of numerous RNA motifs, one might expect that pseudoexons would only arise when rearrangements of intronic DNA create novel exons by chance. Surprisingly, although such mutations do occur, a far more common cause of pseudoexons is deep-intronic single nucleotide variants, raising the question of why these latent exon-like tracts near the mutation sites have not already been purged from the genome by the evolutionary advantage of more efficient splicing. Possible answers may lie in deep intronic splicing processes such as recursive splicing or poison exon splicing. Because these processes utilize intronic motifs that benignly engage with the spliceosome, the regions involved may be more susceptible to exonization than other intronic regions would be. We speculated that a comprehensive study of reported pseudoexons might detect alignments with known deep intronic splice sites and could also permit the characterisation of novel pseudoexon categories. In this report, we present and analyse a catalogue of over 400 published pseudoexon splice events. In addition to confirming prior observations of the most common pseudoexon mutation types, the size of this catalogue also enabled us to suggest new categories for some of the rarer types of pseudoexon mutation. By comparing our catalogue against published datasets of non-canonical splice events, we also found that 15.7% of pseudoexons exhibit some splicing activity at one or both of their splice sites in non-mutant cells. Importantly, this included seven examples of experimentally confirmed recursive splice sites, confirming for the first time a long-suspected link between these two splicing phenomena. These findings have the potential to improve the fidelity of genetic diagnostics and reveal new targets for splice-modulating therapies.
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Affiliation(s)
- Niall P. Keegan
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
| | - Steve D. Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
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7
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Zanetti A, D'Avanzo F, AlSayed M, Brusius-Facchin AC, Chien YH, Giugliani R, Izzo E, Kasper DC, Lin HY, Lin SP, Pollard L, Singh A, Tonin R, Wood T, Morrone A, Tomanin R. Molecular basis of mucopolysaccharidosis IVA (Morquio A syndrome): A review and classification of GALNS gene variants and reporting of 68 novel variants. Hum Mutat 2021; 42:1384-1398. [PMID: 34387910 PMCID: PMC9291100 DOI: 10.1002/humu.24270] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/02/2021] [Accepted: 08/08/2021] [Indexed: 12/18/2022]
Abstract
Mucopolysaccharidosis IVA (MPS IVA, Morquio A syndrome) is a rare autosomal recessive lysosomal storage disorder caused by mutations in the N‐acetylgalactosamine‐6‐sulfatase (GALNS) gene. We collected, analyzed, and uniformly summarized all published GALNS gene variants, thus updating the previous mutation review (published in 2014). In addition, new variants were communicated by seven reference laboratories in Europe, the Middle East, Latin America, Asia, and the United States. All data were analyzed to determine common alleles, geographic distribution, level of homozygosity, and genotype‐phenotype correlation. Moreover, variants were classified according to their pathogenicity as suggested by ACMG. Including those previously published, we assembled 446 unique variants, among which 68 were novel, from 1190 subjects (including newborn screening positive subjects). Variants' distribution was missense (65.0%), followed by nonsense (8.1%), splicing (7.2%), small frameshift deletions(del)/insertions(ins) (7.0%), intronic (4.0%), and large del/ins and complex rearrangements (3.8%). Half (50.4%) of the subjects were homozygous, 37.1% were compound heterozygous, and 10.7% had only one variant detected. The novel variants underwent in silico analysis to evaluate their pathogenicity. All variants were submitted to ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/) to make them publicly available. Mutation updates are essential for the correct molecular diagnoses, genetic counseling, prenatal and preimplantation diagnosis, and disease management.
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Affiliation(s)
- Alessandra Zanetti
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women's and Children's Health, University of Padova, Padova, Italy.,Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Francesca D'Avanzo
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women's and Children's Health, University of Padova, Padova, Italy.,Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Moeenaldeen AlSayed
- King Faisal Specialist Hospital and Research Centre, Faculty of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | | | - Yin-Hsiu Chien
- Department of Medical Genetics and Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Roberto Giugliani
- Department of Genetics/UFRGS, Medical Genetics Service/HCPA, DR BRASIL Research Group/HCPA, and INAGEMP, Porto Alegre, Brazil
| | - Emanuela Izzo
- BioMarin Pharmaceutical Inc., Novato, California, USA
| | | | - Hsiang-Yu Lin
- Division of Genetics and Metabolism, Departments of Pediatrics and Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Shuan-Pei Lin
- Division of Genetics and Metabolism, Departments of Pediatrics and Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Laura Pollard
- Biochemical Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | | | - Rodolfo Tonin
- Molecular and Cell Biology Laboratory, Pediatric Neurology Unit and Laboratories, Meyer Children's Hospital, Florence, Italy.,Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
| | - Tim Wood
- Biochemical Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, South Carolina, USA
| | - Amelia Morrone
- Molecular and Cell Biology Laboratory, Pediatric Neurology Unit and Laboratories, Meyer Children's Hospital, Florence, Italy.,Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Florence, Italy
| | - Rosella Tomanin
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, Department of Women's and Children's Health, University of Padova, Padova, Italy.,Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
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8
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Kingma SDK, Ceulemans B, Kenis S, Jonckheere AI. Are GMI gangliosidosis and Morquio type B two different disorders or part of one phenotypic spectrum? JIMD Rep 2021; 59:90-103. [PMID: 33977034 PMCID: PMC8100397 DOI: 10.1002/jmd2.12204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/12/2021] [Accepted: 01/19/2021] [Indexed: 11/09/2022] Open
Abstract
Monosialotetrahexosylganglioside (GMI) gangliosidosis and Morquio type B (MorB) are two lysosomal storage disorders (LSDs) caused by the same enzyme deficiency, β-galactosidase (βgal). GMI gangliosidosis, associated with GMI ganglioside accumulation, is a neurodegenerative condition characterized by psychomotor regression, visceromegaly, cherry red spot, and facial and skeletal abnormalities. MorB is characterized by prominent and severe skeletal deformities due to keratan sulfate (KS) accumulation. There are only a few reports on intermediate phenotypes between GMI gangliosidosis and MorB. The presentation of two new patients with this rare intermediate phenotype motivated us to review the literature, to study differences and similarities between GMI gangliosidosis and MorB, and to speculate about the possible mechanisms that may contribute to the differences in clinical presentation. In conclusion, we hypothesize that GMI gangliosidosis and MorB are part of one phenotypic spectrum of the same disease and that the classification of LSDs might need to be revised.
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Affiliation(s)
- Sandra D. K. Kingma
- Centre for Metabolic DiseasesUniversity Hospital Antwerp, University of AntwerpEdegem, AntwerpBelgium
- Department of Pediatric NeurologyAntwerp University Hospital, University of AntwerpEdegem, AntwerpBelgium
| | - Berten Ceulemans
- Department of Pediatric NeurologyAntwerp University Hospital, University of AntwerpEdegem, AntwerpBelgium
| | - Sandra Kenis
- Department of Pediatric NeurologyAntwerp University Hospital, University of AntwerpEdegem, AntwerpBelgium
| | - An I. Jonckheere
- Centre for Metabolic DiseasesUniversity Hospital Antwerp, University of AntwerpEdegem, AntwerpBelgium
- Department of Pediatric NeurologyAntwerp University Hospital, University of AntwerpEdegem, AntwerpBelgium
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9
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Caciotti A, Cellai L, Tonin R, Mei D, Procopio E, Di Rocco M, Andaloro A, Antuzzi D, Rampazzo A, Rigoldi M, Forni G, la Marca G, Guerrini R, Morrone A. Morquio B disease: From pathophysiology towards diagnosis. Mol Genet Metab 2021; 132:180-188. [PMID: 33558080 DOI: 10.1016/j.ymgme.2021.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/20/2021] [Accepted: 01/20/2021] [Indexed: 11/25/2022]
Abstract
Morquio B disease is an attenuated phenotype within the spectrum of beta galactosidase (GLB1) deficiencies. It is characterised by dysostosis multiplex, ligament laxity, mildly coarse facies and heart valve defects due to keratan sulphate accumulation, predominantly in the cartilage. Morquio B patients have normal neurological development, setting them apart from those with the more severe GM1 gangliosidosis. Morquio B disease, with an incidence of 1:250.000 to 1:1.000.000 live births, is very rare. Here we report the clinical-biochemical data of nine patients. High amounts of keratan sulfate were detected using LC-MS/MS in the patients' urinary samples, while electrophoresis, the standard procedure of qualitative glycosaminoglycans analysis, failed to identify this metabolite in any of the patients' samples. We performed molecular analyses at gene, gene expression and protein expression levels, for both isoforms of the GLB1 gene, lysosomal GLB1, and the cell-surface expressed Elastin Binding Protein. We characterised three novel GLB1 mutations [c.75 + 2 T > G, c.575A > G (p.Tyr192Cys) and c.2030 T > G (p.Val677Gly)] identified in three heterozygous patients. We also set up a copy number variation assay by quantitative PCR to evaluate the presence of deletions/ insertions in the GLB1 gene. We propose a diagnostic plan, setting out the specific clinical- biochemical and molecular features of Morquio B, in order to avoid misdiagnoses and improve patients' management.
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Affiliation(s)
- Anna Caciotti
- Molecular and Cell Biology Laboratory, Paediatric Neurology Unit and Laboratories, Neuroscience Department, A. Meyer Children's Hospital, Florence, Italy
| | - Lucrezia Cellai
- Molecular and Cell Biology Laboratory, Paediatric Neurology Unit and Laboratories, Neuroscience Department, A. Meyer Children's Hospital, Florence, Italy
| | - Rodolfo Tonin
- Molecular and Cell Biology Laboratory, Paediatric Neurology Unit and Laboratories, Neuroscience Department, A. Meyer Children's Hospital, Florence, Italy
| | - Davide Mei
- Neurogenetics, Paediatric Neurology Unit and Laboratories, Neuroscience Department, A. Meyer Children's Hospital, Florence, Italy
| | - Elena Procopio
- Metabolic and Muscular Unit, A. Meyer Children's Hospital, Florence, Italy
| | - Maja Di Rocco
- Unit of Rare Diseases, Dept of Pediatrics, IRCCS G. Gaslini, Genoa, Italy
| | - Antonio Andaloro
- Unit of Rare Diseases, Dept of Pediatrics, IRCCS G. Gaslini, Genoa, Italy
| | - Daniela Antuzzi
- Pediatric Clinic, Catholic University of "Sacro Cuore", Policlinico "Gemelli", Rome, Italy
| | | | - Miriam Rigoldi
- Mario Negri Institute for Pharmacological Research, IRCCS, Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Bergamo, Italy
| | - Giulia Forni
- Newborn Screening, Biochemistry and Pharmacology Laboratory, A. Meyer Children's Hospital, Florence, Italy
| | - Giancarlo la Marca
- Newborn Screening, Biochemistry and Pharmacology Laboratory, A. Meyer Children's Hospital, Florence, Italy; Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Renzo Guerrini
- Molecular and Cell Biology Laboratory, Paediatric Neurology Unit and Laboratories, Neuroscience Department, A. Meyer Children's Hospital, Florence, Italy; Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Italy
| | - Amelia Morrone
- Molecular and Cell Biology Laboratory, Paediatric Neurology Unit and Laboratories, Neuroscience Department, A. Meyer Children's Hospital, Florence, Italy; Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence, Italy.
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10
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Zanetti A, D'Avanzo F, Bertoldi L, Zampieri G, Feltrin E, De Pascale F, Rampazzo A, Forzan M, Valle G, Tomanin R. Setup and Validation of a Targeted Next-Generation Sequencing Approach for the Diagnosis of Lysosomal Storage Disorders. J Mol Diagn 2020; 22:488-502. [PMID: 32036093 DOI: 10.1016/j.jmoldx.2020.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 11/07/2019] [Accepted: 01/11/2020] [Indexed: 12/14/2022] Open
Abstract
Lysosomal storage disorders (LSDs) are monogenic diseases, due to accumulation of specific undegraded substrates into lysosomes. LSD diagnosis could take several years because of both poor knowledge of these diseases and shared clinical features. The diagnostic approach includes clinical evaluations, biochemical tests, and genetic analysis of the suspected gene. In this study, we evaluated an LSD targeted sequencing panel as a tool capable to potentially reverse this classic diagnostic route. The panel includes 50 LSD genes and 230 intronic sequences conserved among 33 placental mammals. For the validation phase, 56 positive controls, 13 biochemically diagnosed patients, and nine undiagnosed patients were analyzed. Disease-causing variants were identified in 66% of the positive control alleles and in 62% of the biochemically diagnosed patients. Three undiagnosed patients were diagnosed. Eight patients undiagnosed by the panel were analyzed by whole exome sequencing: for two of them, the disease-causing variants were identified. Five patients, undiagnosed by both panel and exome analyses, were investigated through array comparative genomic hybridization: one of them was diagnosed. Conserved intronic fragment analysis, performed in cases unresolved by the first-level analysis, evidenced no candidate intronic variants. Targeted sequencing has low sequencing costs and short sequencing time. However, a coverage >60× to 80× must be ensured and/or Sanger validation should be performed. Moreover, it must be supported by a thorough clinical phenotyping.
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Affiliation(s)
- Alessandra Zanetti
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Francesca D'Avanzo
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Loris Bertoldi
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Guido Zampieri
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Erika Feltrin
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Fabio De Pascale
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Angelica Rampazzo
- Infantile Neuropsychiatric Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Monica Forzan
- Clinical Genetics Unit, University Hospital of Padua, Padua, Italy
| | - Giorgio Valle
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Rosella Tomanin
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy.
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11
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Lin H, Hargreaves KA, Li R, Reiter JL, Wang Y, Mort M, Cooper DN, Zhou Y, Zhang C, Eadon MT, Dolan ME, Ipe J, Skaar TC, Liu Y. RegSNPs-intron: a computational framework for predicting pathogenic impact of intronic single nucleotide variants. Genome Biol 2019; 20:254. [PMID: 31779641 PMCID: PMC6883696 DOI: 10.1186/s13059-019-1847-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 10/03/2019] [Indexed: 12/27/2022] Open
Abstract
Single nucleotide variants (SNVs) in intronic regions have yet to be systematically investigated for their disease-causing potential. Using known pathogenic and neutral intronic SNVs (iSNVs) as training data, we develop the RegSNPs-intron algorithm based on a random forest classifier that integrates RNA splicing, protein structure, and evolutionary conservation features. RegSNPs-intron showed excellent performance in evaluating the pathogenic impacts of iSNVs. Using a high-throughput functional reporter assay called ASSET-seq (ASsay for Splicing using ExonTrap and sequencing), we evaluate the impact of RegSNPs-intron predictions on splicing outcome. Together, RegSNPs-intron and ASSET-seq enable effective prioritization of iSNVs for disease pathogenesis.
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Affiliation(s)
- Hai Lin
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Katherine A Hargreaves
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 950 W Walnut St, Suite 419, Indianapolis, IN, 46202, USA
| | - Rudong Li
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Jill L Reiter
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Yue Wang
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Matthew Mort
- Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - David N Cooper
- Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Yaoqi Zhou
- Institute for Glycomics and School of Informatics and Communication Technology, Griffith University, Parklands Dr., Southport, QLD, 4215, Australia
| | - Chi Zhang
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA
| | - Michael T Eadon
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - M Eileen Dolan
- Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL, 60637, USA
| | - Joseph Ipe
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 950 W Walnut St, Suite 419, Indianapolis, IN, 46202, USA
| | - Todd C Skaar
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, 950 W Walnut St, Suite 419, Indianapolis, IN, 46202, USA.
| | - Yunlong Liu
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, 410 West 10th Street, Suite 5000, Indianapolis, IN, 46202, USA.
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12
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Leong HY, Abdul Azize NA, Chew HB, Keng WT, Thong MK, Mohd Khalid MKN, Hung LC, Mohamed Zainudin N, Ramlee A, Md Haniffa MA, Yakob Y, Ngu LH. Clinical, biochemical and genetic profiles of patients with mucopolysaccharidosis type IVA (Morquio A syndrome) in Malaysia: the first national natural history cohort study. Orphanet J Rare Dis 2019; 14:143. [PMID: 31200731 PMCID: PMC6570902 DOI: 10.1186/s13023-019-1105-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/26/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Mucopolysaccharidosis IVA (MPS IVA) is an autosomal recessive lysosomal storage disease due to N-acetylgalactosamine-6-sulfatase (GALNS) deficiency. It results in accumulation of the glycosaminoglycans, keratan sulfate and chondroitin-6-sulfate, leading to skeletal and other systemic impairments. Data on MPS IVA in Asian populations are scarce. METHODS This is a multicentre descriptive case series of 21 patients comprising all MPS IVA patients in Malaysia. Mutational analysis was performed by PCR and Sanger sequencing of the GALNS gene in 17 patients. RESULTS The patients (15 females and 6 males) had a mean age (± SD) of 15.5 (± 8.1) years. Mean age at symptom onset was 2.6 (± 2.1) years and at confirmed diagnosis was 6.9 (± 4.5) years. The study cohort included patients from all the main ethnic groups in Malaysia - 57% Malay, 29% Chinese and 14% Indian. Common presenting symptoms included pectus carinatum (57%) and genu valgum (43%). Eight patients (38%) had undergone surgery, most commonly knee surgeries (29%) and cervical spine decompression (24%). Patients had limited endurance with lower mean walking distances with increasing age. GALNS gene analysis identified 18 distinct mutations comprising 13 missense, three nonsense, one small deletion and one splice site mutation. Of these, eight were novel mutations (Tyr133Ser, Glu158Valfs*12, Gly168*, Gly168Val, Trp184*, Leu271Pro, Glu320Lys, Leu508Pro). Mutations in exons 1, 5 and 9 accounted for 51% of the mutant alleles identified. CONCLUSIONS All the MPS IVA patients in this study had clinical impairments. A better understanding of the natural history and the clinical and genetic spectrum of MPS IVA in this population may assist early diagnosis, improve management and permit timely genetic counselling and prenatal diagnosis.
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Affiliation(s)
- Huey Yin Leong
- Genetics Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia
| | - Nor Azimah Abdul Azize
- Unit of Molecular Diagnostics & Protein, Institute for Medical Research, Ministry of Health Malaysia, Kuala Lumpur, Malaysia
| | - Hui Bein Chew
- Genetics Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia
| | - Wee Teik Keng
- Genetics Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia
| | - Meow Keong Thong
- Department of Paediatrics, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia
| | - Mohd Khairul Nizam Mohd Khalid
- Unit of Molecular Diagnostics & Protein, Institute for Medical Research, Ministry of Health Malaysia, Kuala Lumpur, Malaysia
| | - Liang Choo Hung
- Paediatric Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Kuala Lumpur, Malaysia
| | - Norzila Mohamed Zainudin
- Paediatric Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Kuala Lumpur, Malaysia
| | - Azura Ramlee
- Ophthalmology Department, Hospital Selayang, Ministry of Health Malaysia, Selayang, Malaysia
| | - Muzhirah Aisha Md Haniffa
- Genetics Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia
| | - Yusnita Yakob
- Unit of Molecular Diagnostics & Protein, Institute for Medical Research, Ministry of Health Malaysia, Kuala Lumpur, Malaysia
| | - Lock Hock Ngu
- Genetics Department, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia
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13
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Tüysüz B, Alkaya DU, Toksoy G, Güneş N, Yıldırım T, Bayhan İA, Uyguner ZO. Mutation spectrum and pivotal features for differential diagnosis of Mucopolysaccharidosis IVA patients with severe and attenuated phenotype. Gene 2019; 704:59-67. [PMID: 30980944 DOI: 10.1016/j.gene.2019.04.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 03/22/2019] [Accepted: 04/08/2019] [Indexed: 01/06/2023]
Abstract
Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by biallelic mutations in GALNS gene and characterized by progressive skeletal deformities with short stature. The aim of this study was to evaluate the genotype, longitudinal height measurement and clinical features of MPS IVA patients. Thirty-two patients from 22 families were enrolled. The ages of patients at diagnosis ranged from two months to 18 years of age, and followed up for three to twenty years. They were classified as severe and attenuated form (intermediate and mild) according to their height measurements. The mean height standard deviation scores (SDS) for Turkish standards at 0-3, 5 and 10 years of ages were found to be -1.1, -4.2 and -7.3 respectively in patients with severe phenotype, while they were +0.4, -1.5 and -3 for intermediate phenotype. Patients with severe form reached a mean final height of -8.5 SDS, and mild phenotype -3.6 SDS. The most common initial and current symptoms in the patients with the severe phenotype were pectus carinatus and/or kyphosis deformities which occurred between 5 months and 3 years of age, and genu valgum deformity which developed after 3 years of age. However, kyphoscoliosis was the most common initial and current findings in the attenuated phenotype. Although, initial symptoms appeared in early childhood in the intermediate phenotype, similar to the severe phenotype, the clinical findings progressed slowly and genu valgum deformity did not develop. In patients with mild phenotype, the onset of symptoms was after 5 years of age. In conclusion, this study provides significant insights into the initial and follow-up clinical features and height values that contribute to the differential diagnosis of the severe and intermediate phenotypes in early childhood. Eleven mutations in GALNS gene in which one of them is novel (c.416G>A) were associated with the severe phenotype and three mutations (c.1038C>A, c.850T>G, c.752G>A) lead to the attenuated phenotype.
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Affiliation(s)
- Beyhan Tüysüz
- Department of Pediatric Genetics, Istanbul University-Cerrahpasa, Medical School, Istanbul, Turkey.
| | - Dilek Uludağ Alkaya
- Department of Pediatric Genetics, Istanbul University-Cerrahpasa, Medical School, Istanbul, Turkey
| | - Güven Toksoy
- Department of Medical Genetics, Istanbul University, Medical School, Istanbul, Turkey
| | - Nilay Güneş
- Department of Pediatric Genetics, Istanbul University-Cerrahpasa, Medical School, Istanbul, Turkey
| | - Timur Yıldırım
- Department of Orthopaedic and Traumatology, Baltalimani Bone Diseases, Training and Research Hospital, Istanbul, Turkey
| | - İlhan Avni Bayhan
- Department of Orthopaedic and Traumatology, Baltalimani Bone Diseases, Training and Research Hospital, Istanbul, Turkey
| | - Zehra Oya Uyguner
- Department of Medical Genetics, Istanbul University, Medical School, Istanbul, Turkey
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14
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Zanetti A, D’Avanzo F, Rigon L, Rampazzo A, Concolino D, Barone R, Volpi N, Santoro L, Lualdi S, Bertola F, Scarpa M, Tomanin R. Molecular diagnosis of patients affected by mucopolysaccharidosis: a multicenter study. Eur J Pediatr 2019; 178:739-753. [PMID: 30809705 PMCID: PMC6459791 DOI: 10.1007/s00431-019-03341-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/05/2019] [Accepted: 02/06/2019] [Indexed: 11/25/2022]
Abstract
Mucopolysaccharidoses (MPS) are a subgroup of 11 monogenic lysosomal storage disorders due to the deficit of activity of the lysosomal hydrolases deputed to the degradation of mucopolysaccharides. Although individually rare, all together they account for at least 1:25,000 live births. In this study, we present the genetic analysis of a population of 71 MPS patients enrolled in a multicenter Italian study. We re-annotated all variants, according to the latest recommendations, and re-classified them as suggested by the American College of Medical Genetics and Genomics. Variant distribution per type was mainly represented by missense mutations. Overall, 10 patients had received no molecular diagnosis, although 6 of them had undergone either HSCT or ERT, based on clinical and enzymatic evaluations. Moreover, nine novel variants are reported.Conclusions: Our analysis underlines the need to complete the molecular diagnosis in patients previously diagnosed only on a biochemical basis, suggests a periodical re-annotation of the variants and solicits their deposition in public databases freely available to clinicians and researchers. We strongly recommend a molecular diagnosis based on the analysis of the "trio" instead of the sole proband. These recommendations will help to obtain a complete and correct diagnosis of mucopolysaccharidosis, rendering also possible genetic counseling. What is known • MPS are a group of 11 metabolic genetic disorders due to deficits of enzymes involved in the mucopolysaccharides degradation. • Molecular analysis is commonly performed to confirm enzymatic assays. What is new • Eighty-six percent of the 71 patients we collected received a molecular diagnosis; among them, 9 novel variants were reported. • We stress the importance of molecular diagnosis in biochemically diagnosed patients, encourage a periodical re-annotation of variants according to the recent nomenclature and their publication in open databases.
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Affiliation(s)
- Alessandra Zanetti
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Francesca D’Avanzo
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Laura Rigon
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Angelica Rampazzo
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
| | | | - Rita Barone
- Department of Clinical and Experimental Medicine, Child Neurology and Psychiatry, University of Catania, Catania, Italy
| | - Nicola Volpi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Lucia Santoro
- Department of Clinical Sciences, Division of Pediatrics, Polytechnic University of Marche, Ospedali Riuniti, Presidio Salesi, Ancona, Italy
| | - Susanna Lualdi
- Laboratorio di Genetica Medica e Biobanche, Istituto Giannina Gaslini, Genoa, Italy
| | - Francesca Bertola
- School of Medicine and Surgery, University of Milano Bicocca, Monza, Italy
| | - Maurizio Scarpa
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Rosella Tomanin
- Laboratorio di Diagnosi e Terapia delle Malattie Lisosomiali, Department of Women’s and Children’s Health, University of Padova, Padova, Italy
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
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