{"entity": "journal", "iuid": "f72e0a741381425fbecb5b14cca99822", "timestamp": "2026-06-08T21:10:45.680Z", "links": {"self": {"href": "https://publications.scilifelab.se/journal/JIMD%20Rep.json"}, "display": {"href": "https://publications.scilifelab.se/journal/JIMD%20Rep"}}, "title": "JIMD Rep", "issn": "2192-8312", "issn-l": "2192-8304", "publications_count": 2, "publications": [{"entity": "publication", "iuid": "0b6d1bc77a9f41d69b002b9ca35b7cb1", "links": {"self": {"href": "https://publications.scilifelab.se/publication/0b6d1bc77a9f41d69b002b9ca35b7cb1.json"}, "display": {"href": "https://publications.scilifelab.se/publication/0b6d1bc77a9f41d69b002b9ca35b7cb1"}}, "title": "Glycosaminoglycan linkage region of urinary bikunin as a potentially useful biomarker for \u03b23GalT6-deficient spondylodysplastic Ehlers-Danlos syndrome.", "authors": [{"family": "Nikpour", "given": "Mahnaz", "initials": "M"}, {"family": "Noborn", "given": "Fredrik", "initials": "F"}, {"family": "Nilsson", "given": "Jonas", "initials": "J"}, {"family": "Van Damme", "given": "Tim", "initials": "T", "orcid": "0000-0002-6424-4421", "researcher": {"href": "https://publications.scilifelab.se/researcher/0857ffa8e2ba4c9595fd5f81f9b9017d.json"}}, {"family": "Kaye", "given": "Olivier", "initials": "O"}, {"family": "Syx", "given": "Delfien", "initials": "D"}, {"family": "Malfait", "given": "Fransiska", "initials": "F"}, {"family": "Larson", "given": "G\u00f6ran", "initials": "G", "orcid": "0000-0002-2616-0366", "researcher": {"href": "https://publications.scilifelab.se/researcher/62a940eae9164c56a1d2f9b8ef8242cd.json"}}], "type": "journal article", "published": "2022-09-00", "journal": {"title": "JIMD Rep", "issn": "2192-8304", "issn-l": null, "volume": "63", "issue": "5", "pages": "462-467"}, "abstract": "The spondylodysplastic type of Ehlers-Danlos syndrome (spEDS) is caused by genetic defects in the B4GALT7 or B3GALT6 genes both deranging the biosynthesis of the glycosaminoglycan linkage region of chondroitin/dermatan sulfate and heparan sulfate proteoglycans. In this study, we have analyzed the linkage regions of urinary chondroitin sulfate proteoglycans of three siblings, diagnosed with spEDS and carrying biallelic pathogenic variants of the B3GALT6 gene. Proteoglycans were digested with trypsin, glycopeptides enriched on anion-exchange columns, depolymerized with chondroitinase ABC, and analyzed by nLC-MS/MS. In urine of the unaffected mother, the dominating glycopeptide of bikunin/protein AMBP appeared as only one dominating (99.9%) peak with the canonical tetrasaccharide linkage region modification. In contrast, the samples of the three affected siblings contained two different glycopeptide peaks, corresponding to the canonical tetrasaccharide and to the non-canonical trisaccharide linkage region modifications in individual ratios of 61/38, 73/27, and 59/41. We propose that the relative distribution of glycosaminoglycan linkage regions of urinary bikunin glycopeptides may serve as a phenotypic biomarker in a diagnostic test but also as a biomarker to follow the effect of future therapies in affected individuals.", "doi": "10.1002/jmd2.12311", "pmid": "36101818", "labels": {"Glycoproteomics and MS Proteomics": "Collaborative"}, "xrefs": [{"db": "pii", "key": "JMD212311"}, {"db": "pmc", "key": "PMC9458601"}], "notes": [], "created": "2022-10-05T12:02:53.432Z", "modified": "2024-01-16T13:46:28.538Z"}, {"entity": "publication", "iuid": "f6d08dca735c4cb6a528b7753b4194e9", "links": {"self": {"href": "https://publications.scilifelab.se/publication/f6d08dca735c4cb6a528b7753b4194e9.json"}, "display": {"href": "https://publications.scilifelab.se/publication/f6d08dca735c4cb6a528b7753b4194e9"}}, "title": "Diagnostic pitfalls in vitamin B6-dependent epilepsy caused by mutations in the PLPBP gene.", "authors": [{"family": "Jensen", "given": "Kristian Vestergaard", "initials": "KV"}, {"family": "Frid", "given": "Maria", "initials": "M"}, {"family": "St\u00f6dberg", "given": "Tommy", "initials": "T"}, {"family": "Barbaro", "given": "Michela", "initials": "M"}, {"family": "Wedell", "given": "Anna", "initials": "A"}, {"family": "Christensen", "given": "Mette", "initials": "M"}, {"family": "Bak", "given": "Mads", "initials": "M"}, {"family": "Ek", "given": "Jakob", "initials": "J"}, {"family": "Madsen", "given": "Camilla G\u00f8bel", "initials": "CG"}, {"family": "Darin", "given": "Niklas", "initials": "N"}, {"family": "Gr\u00f8nborg", "given": "Sabine", "initials": "S"}], "type": "case reports", "published": "2019-11-00", "journal": {"title": "JIMD Rep", "issn": "2192-8304", "volume": "50", "issue": "1", "pages": "1-8", "issn-l": null}, "abstract": "Vitamin B6-responsive epilepsies are a group of genetic disorders including ALDH7A1 deficiency, PNPO deficiency, and others, usually causing neonatal onset seizures resistant to treatment with common antiepileptic drugs. Recently, biallelic mutations in PLPBP were shown to be a novel cause of vitamin B6-dependent epilepsy with a variable phenotype. The different vitamin B6-responsive epilepsies can be detected and distinguished by their respective biomarkers and genetic analysis. Unfortunately, metabolic biomarkers for early detection and prognosis of PLPBP deficiency are currently still lacking. Here, we present data from two further patients with vitamin B6-dependent seizures caused by variants in PLPBP, including a novel missense variant, and compare their genotype and phenotypic presentation to previously described cases. Hyperglycinemia and hyperlactatemia are the most consistently observed biochemical abnormalities in pyridoxal phosphate homeostasis protein (PLPHP) deficient patients and were present in both patients in this report within the first days of life. Lactic acidemia, the neuroradiological, and clinical presentation led to misdiagnosis of a mitochondrial encephalopathy in two previously published cases with an early fatal course. Similarly, on the background of glycine elevation in plasma, glycine encephalopathy was wrongly adopted as diagnosis for a patient in our report. In this regard, lactic acidemia as well as hyperglycinemia appear to be diagnostic pitfalls in patients with vitamin B6-responsive epilepsies, including PLPHP deficiency.\n\nIn vitamin B6-responsive epilepsies, including PLPHP deficiency, there are several diagnostic pitfalls, including lactic acidemia as well as hyperglycinemia, highlighting the importance of a pyridoxine trial, and genetic testing.", "doi": "10.1002/jmd2.12063", "pmid": "31741821", "labels": {"Clinical Genomics Stockholm": "Service", "Clinical Genomics": "Service"}, "xrefs": [{"db": "pii", "key": "JMD212063"}, {"db": "pmc", "key": "PMC6850975"}], "notes": [], "created": "2019-11-25T10:51:42.483Z", "modified": "2019-11-25T10:51:42.500Z"}], "created": "2019-11-25T10:51:42.490Z", "modified": "2020-11-27T13:14:09.492Z"}