{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T17:40:39Z","timestamp":1783359639259,"version":"3.54.6"},"reference-count":20,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,1,14]],"date-time":"2020-01-14T00:00:00Z","timestamp":1578960000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100009633","name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development","doi-asserted-by":"publisher","award":["HHSN275201400017C"],"award-info":[{"award-number":["HHSN275201400017C"]}],"id":[{"id":"10.13039\/100009633","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009633","name":"Eunice Kennedy Shriver National Institute of Child Health and Human Development","doi-asserted-by":"publisher","award":["HSN275201500001I"],"award-info":[{"award-number":["HSN275201500001I"]}],"id":[{"id":"10.13039\/100009633","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJNS"],"abstract":"<jats:p>We conducted a pilot newborn screening (NBS) study for Pompe disease (PD) and mucopolysaccharidosis type I (MPS I) in the multiethnic population of Georgia. We screened 59,332 infants using a two-tier strategy of flow injection tandem mass spectrometry (FIA-MSMS) enzyme assays. The first tier of testing was a 2-plex assay measuring PD and MPS I enzyme activity, followed by a second-tier test with additional enzymes to improve specificity. Interpretation of results was performed using post-analytical tools created using Collaborative Laboratory Integrated Reports (CLIR). We identified a single case of infantile onset PD, two cases of late onset PD, and one pseudodeficiency. The positive predictive value (PPV) for PD screening during the study was 66.7%. No cases of MPS I were identified during the study period, but there were 2 confirmed cases of pseudodeficiency and 6 cases lost to follow up. The two-tier screening strategy was successful in reducing false positive results and allowed for the identification and early treatment of a case of infantile PD but the frequency of pseudodeficiency in MPS I is problematic. Molecular testing is required and should be covered by the screening program to avoid delays in case resolution.<\/jats:p>","DOI":"10.3390\/ijns6010002","type":"journal-article","created":{"date-parts":[[2020,1,15]],"date-time":"2020-01-15T10:30:27Z","timestamp":1579084227000},"page":"2","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Two-Tiered Newborn Screening with Post-Analytical Tools for Pompe Disease and Mucopolysaccharidosis Type I Results in Performance Improvement and Future Direction"],"prefix":"10.3390","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9218-6233","authenticated-orcid":false,"given":"Patricia L.","family":"Hall","sequence":"first","affiliation":[{"name":"Department of Human Genetics, Emory University, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0423-2557","authenticated-orcid":false,"given":"Rossana","family":"Sanchez","sequence":"additional","affiliation":[{"name":"Department of Human Genetics, Emory University, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arthur F.","family":"Hagar","sequence":"additional","affiliation":[{"name":"Georgia Department of Public Health, Atlanta, GA 30303, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. Caleb","family":"Jerris","sequence":"additional","affiliation":[{"name":"EGL Genetics, Tucker, GA 30084, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angela","family":"Wittenauer","sequence":"additional","affiliation":[{"name":"Department of Human Genetics, Emory University, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William R.","family":"Wilcox","sequence":"additional","affiliation":[{"name":"Department of Human Genetics, Emory University, Atlanta, GA 30322, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1038\/gim.2017.194","article-title":"Precision newborn screening for lysosomal disorders","volume":"20","author":"Stoway","year":"2018","journal-title":"Genet. 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