{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T12:02:49Z","timestamp":1784203369344,"version":"3.55.0"},"reference-count":25,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2021,8,10]],"date-time":"2021-08-10T00:00:00Z","timestamp":1628553600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>Introduction: Childhood epilepsy is one of the most common neurological problems. The transferrin isoelectric focusing (TIEF) test is a screening test for congenital disorders of glycosylation (CDG). We identified abnormal TIEF test in children with epilepsy in our epilepsy genetics clinic. To determine if an abnormal TIEF test is associated with anti-epileptic medications or abnormal liver functions, we performed a retrospective cohort study. Methods: This study was performed between January 2012 and March 2020. Electronic patient charts were reviewed. Standard non-parametric statistical tests were applied using R statistical software. Fischer\u2019s exact test was used for comparisons. Results: There were 206 patients. The TIEF test was abnormal in 11% (23 out of 206) of the patients. Nine patients were diagnosed with CDG: PMM2-CDG (n = 5), ALG3-CDG (n = 1), ALG11-CDG (n = 2), SLC35A2-CDG (n = 1). We report 51 different genetic diseases in 84 patients. Two groups, (1) abnormal TIEF test; (2) normal TIEF test, showed statistically significant differences for abnormal liver functions and for valproic acid treatment. Conclusion: The TIEF test guided CDG diagnosis in 2.9% of the patients. Due to the high prevalence of CDG (4.4%) in childhood epilepsy, the TIEF test might be included into the diagnostic investigations to allow earlier and cost-effective diagnosis.<\/jats:p>","DOI":"10.3390\/genes12081227","type":"journal-article","created":{"date-parts":[[2021,8,10]],"date-time":"2021-08-10T08:57:14Z","timestamp":1628585834000},"page":"1227","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Prevalence of Congenital Disorders of Glycosylation in Childhood Epilepsy and Effects of Anti-Epileptic Drugs on the Transferrin Isoelectric Focusing Test"],"prefix":"10.3390","volume":"12","author":[{"given":"Grace","family":"Silver","sequence":"first","affiliation":[{"name":"Department of Pediatrics, Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shalini","family":"Bahl","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dawn","family":"Cordeiro","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abhinav","family":"Thakral","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taryn","family":"Athey","sequence":"additional","affiliation":[{"name":"Department of Medical Genetics, University of Alberta, Stollery Children\u2019s Hospital, Edmonton, AB T6G 2H7, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8396-6764","authenticated-orcid":false,"given":"Saadet","family":"Mercimek-Andrews","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada"},{"name":"Department of Medical Genetics, University of Alberta, Stollery Children\u2019s Hospital, Edmonton, AB T6G 2H7, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1111\/epi.12954","article-title":"Diagnostic yield of genetic testing in epileptic encephalopathy in childhood","volume":"56","author":"Patel","year":"2015","journal-title":"Epilepsia"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/j.neuroscience.2019.08.016","article-title":"Clinical Application of Targeted Next-Generation Sequencing Panels and Whole Exome Sequencing in Childhood Epilepsy","volume":"418","author":"Costain","year":"2019","journal-title":"Neuroscience"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/0009-8981(84)90059-7","article-title":"Sialic acid-deficient serum and cerebrospinal fluid transferrin in a newly recognized genetic syndrome","volume":"144","author":"Jaeken","year":"1984","journal-title":"Clin. 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