title: Glycine N-Methyltransferase Deficiency: A Member of Dysmethylating Liver Disorders?
abstract: Glycine N-methyltransferase deficiency is an inherited disorder of methionine metabolism, reported so far in only four patients and characterised by permanent hypermethioninemia. This disorder has been considered as probably benign because moderate hepatomegaly in two patients was the only obvious symptom and mild to moderate elevation of aminotransferases the only laboratory abnormality. Our experience with the current novel patient points out that this disease, due to very high hypermethioninemia, is not harmless and that there may be diagnostic pitfalls in interpretation of biochemical hallmarks of the disease. Since the first description of glycine N-methyltransferase deficiency, other disorders of this metabolic pathway affecting the liver have been reported pointing to dysmethylation as the common pathogenetic mechanism. Therefore, we suggest the whole group to be named dysmethylating liver diseases.
authors.affiliation: Department of Pediatrics, University Hospital Center Zagreb, Zagreb, Croatia. ibaric@kbc-zagreb.hr.|School of Medicine, University of Zagreb, Zagreb, Croatia. ibaric@kbc-zagreb.hr.
authors.forename: Ivo
authors.initials: I
authors.lastname: Barić
authors.affiliation: Division of Metabolism, Department of Pediatrics, Uludag University Faculty of Medicine, Gorukle, Bursa, Turkey.
authors.forename: Sahin
authors.initials: S
authors.lastname: Erdol
authors.affiliation: Division of Metabolism, Department of Pediatrics, Uludag University Faculty of Medicine, Gorukle, Bursa, Turkey.
authors.forename: Halil
authors.initials: H
authors.lastname: Saglam
authors.affiliation: Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Mila
authors.initials: M
authors.lastname: Lovrić
authors.affiliation: Department of Molecular Medicine, Institute Ruđer Bošković, Zagreb, Croatia.
authors.forename: Robert
authors.initials: R
authors.lastname: Belužić
authors.affiliation: Department of Molecular Medicine, Institute Ruđer Bošković, Zagreb, Croatia.
authors.forename: Oliver
authors.initials: O
authors.lastname: Vugrek
authors.affiliation: Department of General Pediatrics, Adolescent Medicine and Neonatology, University Medical Centre Freiburg, Freiburg, Germany.
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Blom
authors.affiliation: Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Ksenija
authors.initials: K
authors.lastname: Fumić
keywords: Glycine-N-methyltransferase deficiency; Hypermethioninemia; Inherited liver disease; Methylation disorders