{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T20:19:07Z","timestamp":1790540347042,"version":"4.1.0"},"reference-count":41,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,11,26]],"date-time":"2024-11-26T00:00:00Z","timestamp":1732579200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sanofi Aventis","award":["LYSOSPAIN"],"award-info":[{"award-number":["LYSOSPAIN"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>(1) Background: Most rare disease patients endure long delays in obtaining a correct diagnosis, the so-called \u201cdiagnostic odyssey\u201d, due to a combination of the rarity of their disorder and the lack of awareness of rare diseases among both primary care professionals and specialists. Next-generation sequencing (NGS) techniques that target genes underlying diverse phenotypic traits or groups of diseases are helping reduce these delays; (2) Methods: We used a combination of biochemical (thin-layer chromatography and high-performance liquid chromatography-tandem mass spectrometry), NGS (resequencing gene panels) and splicing assays to achieve a complete diagnosis of three patients with suspected metachromatic leukodystrophy, a neurologic lysosomal disorder; (3) Results: Affected individuals in each family were homozygotes for harmful variants in the ARSA gene, one of them novel (c.854+1dup, in family 1) and the other already described (c.640G&gt;A, p.(Ala214Thr), in family 2). In addition, both affected individuals in family 2 were carriers of a known pathogenic variant in an additionallysosomal disease gene, GNPTAB (for mucolipidosis III). This additional variant may modify the clinical presentation by increasing lysosomal dysfunction. (4) Conclusions: We demonstrated the deleterious effect of the novel variant c.854+1dup on the splicing of ARSA transcripts. We also confirmed the involvement of variant c.640G&gt;A in metachromatic leukodystrophy. Our results show the power of diagnostic approaches that combine deep phenotyping, NGS, and biochemical and functional techniques.<\/jats:p>","DOI":"10.3390\/genes15121515","type":"journal-article","created":{"date-parts":[[2024,11,26]],"date-time":"2024-11-26T05:06:53Z","timestamp":1732597613000},"page":"1515","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Metachromatic Leukodystrophy in Morocco: Identification of Causative Variants by Next-Generation Sequencing (NGS)"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-9844-583X","authenticated-orcid":false,"given":"Miloud","family":"Hammoud","sequence":"first","affiliation":[{"name":"Metabolic Platform, Biochemistry Laboratory, Team for Childhood, Health and Development, Faculty of Medicine, Cadi Ayyad University, Marrakech B.P. 7010, Morocco"},{"name":"Moroccan Association for Inherited Metabolic Diseases, Morocco"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7583-0370","authenticated-orcid":false,"given":"Mar\u00eda","family":"Dom\u00ednguez-Ruiz","sequence":"additional","affiliation":[{"name":"Servicio de Gen\u00e9tica, Hospital Universitario Ram\u00f3n y Cajal, IRYCIS, 28034 Madrid, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Enfermedades Raras (CIBERER), 28034 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Imane","family":"Assiri","sequence":"additional","affiliation":[{"name":"Metabolic Platform, Biochemistry Laboratory, Team for Childhood, Health and Development, Faculty of Medicine, Cadi Ayyad University, Marrakech B.P. 7010, Morocco"},{"name":"Moroccan Association for Inherited Metabolic Diseases, Morocco"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2934-1699","authenticated-orcid":false,"given":"Daniel","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Congenital Metabolic Diseases Unit, Department of Neonatology, University Clinical Hospital of Santiago de Compostela, Instituto de Investigaci\u00f3n Sanitaria de Santiago (IDIS), European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15706 Santiago de Compostela, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Enfermedades Raras (CIBERER), 15706 Santiago de Compostela, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nisrine","family":"Aboussair","sequence":"additional","affiliation":[{"name":"Genetics Department, Clinical Research Center, Mohammed VI University Hospital, Faculty of Medicine and Pharmacy, Cadi Ayyad University, Marrakech-Principal B.P. 2360, Morocco"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Val F.","family":"Lanza","sequence":"additional","affiliation":[{"name":"UCA de Gen\u00f3mica Traslacional y Bioinform\u00e1tica (UCA-GTB), Hospital Universitario Ram\u00f3n y Cajal, IRYCIS, 28034 Madrid, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Enfermedades Infecciosas (CIBERINFEC), 28034 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jes\u00fas","family":"Villarrubia","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Universitario Ram\u00f3n y Cajal, IRYCIS, 28034 Madrid, Spain"},{"name":"CSUR de Enfermedades Metab\u00f3licas, European Reference Network for Hereditary Metabolic Disorders (MetabERN), Hospital Universitario Ram\u00f3n y Cajal, IRYCIS, 28034 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9711-2812","authenticated-orcid":false,"given":"Crist\u00f3bal","family":"Col\u00f3n","sequence":"additional","affiliation":[{"name":"Congenital Metabolic Diseases Unit, Department of Neonatology, University Clinical Hospital of Santiago de Compostela, Instituto de Investigaci\u00f3n Sanitaria de Santiago (IDIS), European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15706 Santiago de Compostela, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Enfermedades Raras (CIBERER), 15706 Santiago de Compostela, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naima","family":"Fdil","sequence":"additional","affiliation":[{"name":"Metabolic Platform, Biochemistry Laboratory, Team for Childhood, Health and Development, Faculty of Medicine, Cadi Ayyad University, Marrakech B.P. 7010, Morocco"},{"name":"Moroccan Association for Inherited Metabolic Diseases, Morocco"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0467-4320","authenticated-orcid":false,"given":"Francisco J.","family":"del Castillo","sequence":"additional","affiliation":[{"name":"Servicio de Gen\u00e9tica, Hospital Universitario Ram\u00f3n y Cajal, IRYCIS, 28034 Madrid, Spain"},{"name":"Centro de Investigaci\u00f3n Biom\u00e9dica en Red de Enfermedades Raras (CIBERER), 28034 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1002\/ajh.20908","article-title":"Consequences of diagnostic delays in type 1 Gaucher disease: The need for greater awareness among hematologists-oncologists and an opportunity for early diagnosis and intervention","volume":"82","author":"Mistry","year":"2007","journal-title":"Am. J. Hematol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"100808","DOI":"10.1016\/j.gimo.2023.100808","article-title":"Educational needs in diagnosing rare diseases: A multinational, multispecialty clinician survey","volume":"1","author":"Bomberger","year":"2023","journal-title":"Genet. Med. Open"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e027248","DOI":"10.1136\/bmjopen-2018-027248","article-title":"Prevalence and practice for rare diseases in primary care: A national cross-sectional study in the USA","volume":"9","author":"Jo","year":"2019","journal-title":"BMJ Open"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e1192","DOI":"10.1016\/S2214-109X(24)00134-7","article-title":"Global health for rare diseases through primary care","volume":"12","author":"Baynam","year":"2024","journal-title":"Lancet Glob. Health"},{"key":"ref_5","unstructured":"Global Commision to End the Diagnostic Odyssey for Children with a Rare Disease (2024, September 02). Ending the Diagnostic Odyssey for Children with a Rare Disease: Year One Report. Available online: https:\/\/globalrarediseasecommission.com\/our-work\/."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1038\/s41572-018-0025-4","article-title":"Lysosomal storage diseases","volume":"4","author":"Platt","year":"2018","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1038\/nrd.2017.214","article-title":"Emptying the stores: Lysosomal diseases and therapeutic strategies","volume":"17","author":"Platt","year":"2018","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1146\/annurev-genom-083118-015345","article-title":"New diagnostic approaches for undiagnosed rare genetic diseases","volume":"21","author":"Hartley","year":"2020","journal-title":"Annu. Rev. Genomics Hum. Genet."},{"key":"ref_9","first-page":"53","article-title":"Early detection of lysosomal diseases by screening of cases of idiopathic splenomegaly and\/or thrombocytopenia with a next-generation sequencing gene panel","volume":"51","author":"Ciubotariu","year":"2019","journal-title":"JIMD Rep."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Shaimardanova, A.A., Chulpanova, D.S., Solovyeva, V.V., Mullagulova, A.I., Kitaeva, K.V., Allegrucci, C., and Rizvanov, A.A. (2020). Metachromatic leukodystrophy: Diagnosis, modeling, and treatment approaches. Front. Med., 7.","DOI":"10.3389\/fmed.2020.576221"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106751","DOI":"10.1016\/j.prostaglandins.2023.106751","article-title":"Sphingolipidoses in Morocco: Chemical profiling for an affordable and rapid diagnosis strategy","volume":"168","author":"Hammoud","year":"2023","journal-title":"Prostaglandins Other Lipid Mediat."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1007\/BF02871008","article-title":"Serum arylsulfatase A assay in metachromatic leukodystrophy: An experience in a neuropsychiatric set-up","volume":"10","author":"Christopher","year":"1995","journal-title":"Indian J. Clin. Biochem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"824","DOI":"10.1016\/S0022-3476(73)80377-4","article-title":"Metachromatic leukodystrophy: Detection in serum","volume":"83","author":"Beratis","year":"1973","journal-title":"J. Pediatr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1373\/clinchem.2015.245159","article-title":"Sulfatide analysis by mass spectrometry for screening of metachromatic leukodystrophy in dried blood and urine samples","volume":"62","author":"Spacil","year":"2016","journal-title":"Clin. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1038\/s41436-020-01017-5","article-title":"Toward newborn screening of metachromatic leukodystrophy: Results from analysis of over 27,000 newborn dried blood spots","volume":"23","author":"Hong","year":"2021","journal-title":"Genet. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6341","DOI":"10.1021\/acs.analchem.9b05274","article-title":"Leukocyte and dried blood spot arylsulfatase A assay by tandem mass spectrometry","volume":"92","author":"Hong","year":"2020","journal-title":"Anal. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"S36","DOI":"10.1016\/j.ymgme.2021.11.080","article-title":"Genetic screening of lysosomal disorders: An account of five years\u2019 experience with NGS-based resequencing panels","volume":"135","author":"Ciubotariu","year":"2022","journal-title":"Mol. Genet. Metab."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"733","DOI":"10.1038\/gim.2013.92","article-title":"ACMG clinical laboratory standards for next-generation sequencing","volume":"15","author":"Rehm","year":"2013","journal-title":"Genet. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1038\/gim.2015.30","article-title":"ACMG Laboratory Quality Assurance Committee. Standards and guidelines for the interpretation of sequence variants: A joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology","volume":"17","author":"Richards","year":"2015","journal-title":"Genet. Med."},{"key":"ref_20","unstructured":"(2024, September 20). VarSome: The Human Genomic Variant Search Engine. Available online: https:\/\/varsome.com\/."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/j.ejpn.2024.03.003","article-title":"Newborn screening in metachromatic leukodystrophy\u2014European consensus-based recommendations on clinical management","volume":"49","author":"Laugwitz","year":"2024","journal-title":"Eur. J. Paediatr. Neurol."},{"key":"ref_22","unstructured":"(2024, October 09). ClinVar, Available online: https:\/\/www.ncbi.nlm.nih.gov\/clinvar\/."},{"key":"ref_23","unstructured":"(2024, October 09). Online Mendelian Inheritance in Man (OMIM). Available online: https:\/\/omim.org\/."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1089\/cmb.1997.4.311","article-title":"Improved splice site detection in Genie","volume":"4","author":"Reese","year":"1997","journal-title":"J. Comput. Biol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1089\/1066527041410418","article-title":"Maximum entropy modeling of short sequence motifs with applications to RNA splicing signals","volume":"11","author":"Yeo","year":"2004","journal-title":"J. Comput. Biol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"W446","DOI":"10.1093\/nar\/gkab266","article-title":"MutationTaster2021","volume":"49","author":"Steinhaus","year":"2021","journal-title":"Nucl. Acids Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1038\/s41586-023-06045-0","article-title":"A genomic mutational constraint map using variation in 76,156 human genomes","volume":"625","author":"Chen","year":"2024","journal-title":"Nature"},{"key":"ref_28","unstructured":"(2024, October 08). IGSR: The International Genome Sample Resource and the 1000 Genomes Project. Available online: https:\/\/www.internationalgenome.org."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2361068","DOI":"10.1155\/2018\/2361068","article-title":"Identification of Novel ARSA Mutations in Chinese Patients with Metachromatic Leukodystrophy","volume":"2018","author":"Chen","year":"2018","journal-title":"Int. J. Genomics"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3497","DOI":"10.1093\/hmg\/ddv100","article-title":"Analyses of disease-related GNPTAB mutations define a novel GlcNAc-1-phosphotransferase interaction domain and an alternative site-1 protease cleavage site","volume":"24","author":"Velho","year":"2015","journal-title":"Hum. Mol. Genet."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.clineuro.2008.09.007","article-title":"\u03b2-mannosidosis: A new cause of spinocerebellar ataxia","volume":"111","author":"Labauge","year":"2009","journal-title":"Clin. Neurol. Neurosurg."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"9436","DOI":"10.1073\/pnas.86.23.9436","article-title":"Arylsulfatase A pseudodeficiency: Loss of a polyadenylylation signal and N-glycosylation site","volume":"86","author":"Gieselmann","year":"1989","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1002\/jmd2.12293","article-title":"Extremely low arylsulfatase a enzyme activity does not necessarily cause symptoms: A long-term follow-up and review of the literature","volume":"63","author":"Laugwitz","year":"2022","journal-title":"JIMD Rep."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/j.ymgme.2022.09.009","article-title":"Predicting clinical phenotypes of metachromatic leukodystrophy based on the arylsulfatase A activity and the ARSA genotype?\u2014Chances and challenges","volume":"137","author":"Santhanakumaran","year":"2022","journal-title":"Mol. Genet. Metab."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Khan, S.A., and Tomatsu, S.C. (2020). Mucolipidoses overview: Past, present, and future. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21186812"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1202","DOI":"10.1002\/mds.28987","article-title":"Role of lysosomal gene variants in modulating GBA-associated Parkinson\u2019s disease risk","volume":"37","author":"Straniero","year":"2022","journal-title":"Mov. Disord."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Yu, M., Ye, H., De-Paula, R.B., Mangleburg, C.G., Wu, T., Lee, T.V., Li, Y., Duong, D., Phillips, B., and Cruchaga, C. (2023). Functional screening of lysosomal storage disorder genes identifies modifiers of \u03b1-synuclein neurotoxicity. PLoS Genet., 19.","DOI":"10.1371\/journal.pgen.1010760"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1080\/15548627.2018.1509818","article-title":"Mitochondrial dysfunction and mitophagy defect triggered by heterozygous GBA mutations","volume":"15","author":"Li","year":"2019","journal-title":"Autophagy"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Smith, L., and Schapira, A.H.V. (2022). GBA variants and Parkinson disease: Mechanisms and treatments. Cells, 11.","DOI":"10.3390\/cells11081261"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Root, J., Merino, P., Nuckols, A., Johnson, M., and Kukar, T. (2021). Lysosome dysfunction as a cause of neurodegenerative diseases: Lessons from frontotemporal dementia and amyotrophic lateral sclerosis. Neurobiol. Dis., 154.","DOI":"10.1016\/j.nbd.2021.105360"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1097\/MOP.0000000000001072","article-title":"Occam\u2019s razor dulled: The occurrence of multiple genetic diagnoses","volume":"33","author":"Linscott","year":"2021","journal-title":"Curr. Opin. Pediatr."}],"container-title":["Genes"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4425\/15\/12\/1515\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:39:38Z","timestamp":1760114378000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4425\/15\/12\/1515"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,26]]},"references-count":41,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["genes15121515"],"URL":"https:\/\/doi.org\/10.3390\/genes15121515","relation":{},"ISSN":["2073-4425"],"issn-type":[{"value":"2073-4425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,26]]}}}