title: A novel mutation (G233D) in the glycogen phosphorylase gene in a patient with hepatic glycogen storage disease and residual enzyme activity.
abstract: We identified a novel mutation in the glycogen phosphorylase gene (PGYL) in a Chinese patient with glycogen storage disease (GSD) type VI. The patient presented with gross hepatomegaly since the age of two without history of any hypoglycemic attack. Otherwise, he was largely asymptomatic. Liver tissue enzyme assays revealed a mild deficiency of total glycogen phosphorylase. Both PGYL and PHKA2 genes were sequenced. The patient was homozygous of a missense mutation G233D in PGYL. This location forms a hairpin turn secondary structure and the small glycine residue is completely conserved in all the orthologous proteins from Escherichia coli to mammals. This is the sixth reported mutation of this form of GSD.
authors.affiliation: Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, China. nelsontang@cuhk.edu.hk
authors.forename: Nelson L S
authors.initials: NL
authors.lastname: Tang
authors.forename: Joannie
authors.initials: J
authors.lastname: Hui
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Young
authors.forename: Viki
authors.initials: V
authors.lastname: Worthington
authors.forename: Ka-Fai
authors.initials: KF
authors.lastname: To
authors.forename: Kam-Lau
authors.initials: KL
authors.lastname: Cheung
authors.forename: Chi-Kong
authors.initials: CK
authors.lastname: Li
authors.forename: Tai-Fai
authors.initials: TF
authors.lastname: Fok
mesh_terms: D000595:Amino Acid Sequence; D002648:Child; D017124:Conserved Sequence; D005091:Exons; D025001:Glycogen Phosphorylase, Liver Form / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006013:Glycogen Storage Disease Type VI / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006529:Hepatomegaly / Q000235:genetics / Q000473:pathology; D006801:Humans; D008297:Male; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010764:Phosphorylase Kinase / Q000235:genetics; D011487:Protein Conformation
chemical_list: D025001:Glycogen Phosphorylase, Liver Form; D010764:Phosphorylase Kinase