{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T03:57:15Z","timestamp":1788321435826,"version":"build-2803163510"},"reference-count":7,"publisher":"Oxford University Press (OUP)","issue":"1","license":[{"start":{"date-parts":[[2011,1,1]],"date-time":"2011-01-01T00:00:00Z","timestamp":1293840000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"funder":[{"name":"Scott, BioMarin Pharmaceuticals Inc."},{"DOI":"10.13039\/100000002","name":"NIH","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000062","name":"National Institute of Diabetes and Digestive and Kidney Diseases","doi-asserted-by":"publisher","award":["R01 DK067859"],"award-info":[{"award-number":["R01 DK067859"]}],"id":[{"id":"10.13039\/100000062","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2011,1,1]]},"abstract":"<jats:sec>\n                  <jats:title>BACKGROUND<\/jats:title>\n                  <jats:p>Treatments are being developed for an increasing number of mucopolysaccharidoses, and early diagnosis is expected to be necessary to maximize the benefits of therapy. Therefore, we developed an assay for N-acetylgalactosamine-6-sulfate sulfatase (GALNS), the enzyme deficient in mucopolysaccharidosis IVA (Morquio A syndrome), that is applicable for clinical diagnosis.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>METHODS<\/jats:title>\n                  <jats:p>A novel substrate for GALNS was synthesized for a new enzyme activity assay that is based on tandem mass spectrometry and uses dried blood spots (DBSs) as the enzyme source. We optimized the assay conditions, including the substrate concentration, reaction pH, lead formate concentration, incubation time, punch size of the DBS, and mass spectrometer conditions. We also assessed inter- and intraassay variation.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>RESULTS<\/jats:title>\n                  <jats:p>The assay uses either solid-phase or liquid-phase extraction before analysis by mass spectrometry. An evaluation of blood spots from 90 randomly chosen healthy newborns and 9 patients with Morquio A syndrome showed a well-defined interval between their respective enzyme activities. Inter- and intraassay imprecision was &amp;lt;10%.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>CONCLUSIONS<\/jats:title>\n                  <jats:p>This tandem mass spectrometry assay requires a minimal number of sample-preparation steps, thus making it easy to implement. The assay has the potential to be adopted for early diagnosis of Morquio A syndrome. We believe this assay could be performed in a multiplex fashion with assays for other lysosomal enzymes.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1373\/clinchem.2010.149880","type":"journal-article","created":{"date-parts":[[2010,10,29]],"date-time":"2010-10-29T00:24:28Z","timestamp":1288311868000},"page":"128-131","source":"Crossref","is-referenced-by-count":48,"title":["Tandem Mass Spectrometry for the Direct Assay of Lysosomal Enzymes in Dried Blood Spots:Application to Screening Newborns for Mucopolysaccharidosis IVA"],"prefix":"10.1093","volume":"57","author":[{"given":"Tanvir","family":"Khaliq","sequence":"first","affiliation":[{"name":"Departments of Chemistry"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martin","family":"Sadilek","sequence":"first","affiliation":[{"name":"Departments of Chemistry"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C Ronald","family":"Scott","sequence":"first","affiliation":[{"name":"Pediatrics, and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frantisek","family":"Turecek","sequence":"first","affiliation":[{"name":"Departments of Chemistry"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael H","family":"Gelb","sequence":"first","affiliation":[{"name":"Departments of Chemistry"},{"name":"Biochemistry, University of Washington, Seattle, WA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2011,1,1]]},"reference":[{"key":"2020022704523913800_B1","first-page":"3421","article-title":"The mucopolysaccharidoses","volume-title":"The metabolic and molecular bases of inherited disease","author":"Neufeld","year":"2001","edition":"8th ed."},{"key":"2020022704523913800_B2","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/0009-8981(90)90339-T","article-title":"A fluorimetric enzyme assay for the diagnosis of Morquio disease type A (MPS IV A)","volume":"187","author":"van Diggelen","year":"1990","journal-title":"Clin Chim Acta"},{"key":"2020022704523913800_B3","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/0009-8981(78)90157-2","article-title":"A sensitive procedure for the diagnosis of N-acetylgalactosamine-6-sulphate sulphatase deficiency in classical Morquio's disease","volume":"88","author":"Glossl","year":"1978","journal-title":"Clin Chim Acta"},{"key":"2020022704523913800_B4","doi-asserted-by":"crossref","first-page":"1785","DOI":"10.1373\/clinchem.2004.035907","article-title":"Direct multiplex assay of lysosomal enzymes in dried blood spots for newborn screening","volume":"50","author":"Li","year":"2004","journal-title":"Clin Chem"},{"key":"2020022704523913800_B5","doi-asserted-by":"crossref","first-page":"2067","DOI":"10.1373\/clinchem.2008.115410","article-title":"Tandem mass spectrometry for the direct assay of lysosomal enzymes in dried blood spots: application to screening newborns for mucopolysaccharidosis I","volume":"54","author":"Blanchard","year":"2008","journal-title":"Clin Chem"},{"key":"2020022704523913800_B6","doi-asserted-by":"crossref","first-page":"5994","DOI":"10.1016\/j.bmcl.2010.08.080","article-title":"Design and synthesis of substrates for newborn screening of Maroteaux-Lamy and Morquio A syndromes","volume":"20","author":"Duffey","year":"2010","journal-title":"Bioorg Med Chem Lett"},{"key":"2020022704523913800_B7","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1093\/oxfordjournals.jbchem.a123697","article-title":"N-Acetylgalactosamine-6-sulfate sulfatase in human placenta: purification and characteristics","volume":"110","author":"Masue","year":"1991","journal-title":"J Biochem"}],"container-title":["Clinical Chemistry"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/academic.oup.com\/clinchem\/article-pdf\/57\/1\/128\/32654476\/clinchem0128.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/academic.oup.com\/clinchem\/article-pdf\/57\/1\/128\/32654476\/clinchem0128.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,2,27]],"date-time":"2020-02-27T04:53:57Z","timestamp":1582779237000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/clinchem\/article\/57\/1\/128\/5621235"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,1,1]]},"references-count":7,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2011,1,1]]},"published-print":{"date-parts":[[2011,1,1]]}},"URL":"https:\/\/doi.org\/10.1373\/clinchem.2010.149880","relation":{},"ISSN":["0009-9147","1530-8561"],"issn-type":[{"value":"0009-9147","type":"print"},{"value":"1530-8561","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2011,1,1]]},"published":{"date-parts":[[2011,1,1]]}}}