A novel mutation (G233D) in the glycogen phosphorylase gene in a patient with hepatic glycogen storage disease and residual enzyme activity.
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.
Tang
Nelson L S
NL
Department of Chemical Pathology, Faculty of Medicine, The Chinese University of Hong Kong, China. nelsontang@cuhk.edu.hk
Hui
Joannie
J
Young
Elisabeth
E
Worthington
Viki
V
To
Ka-Fai
KF
Cheung
Kam-Lau
KL
Li
Chi-Kong
CK
Fok
Tai-Fai
TF
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
D025001:Glycogen Phosphorylase, Liver Form; D010764:Phosphorylase Kinase