X-linked liver glycogenosis in a Taiwanese family: transmission from undiagnosed males.
X-linked liver glycogenosis (XLG), also known as glycogen storage disease type-lXa, is characterized by hepatomegaly, abnormal liver functions and growth retardation. It is caused by mutations in the PHKA2 gene that encodes the alpha-subunit of phosphorylase kinase (PHK). XLG can be divided into two subtypes: XLG-I, with a deficiency in PHK activity in peripheral blood cells and the liver; and XLG-II, with normal PHK activity in vitro. This report describes two boys who presented with hepatomegaly and abnormal liver function. Pedigree analysis revealed them to be fifth-degree relatives, with the disease transmitted through undiagnosed grandfathers. Liver histology confirmed GSD diagnosis, and both cases had a deficiency in PHK activity in red blood cells and liver tissues. This is the first report of XLG-I in the ethnic-Chinese population in Taiwan. This report indicates that XLG may be undiagnosed or underestimated. A correct diagnosis is necessary for proper management and genetic counseling.
Chen
Szu-Ta
ST
Department of Pediatrics, National Taiwan University Children's Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Chen
Huey-Ling
HL
Ni
Yen-Hsuan
YH
Chien
Yin-Hsiu
YH
Jeng
Yung-Ming
YM
Chang
Mei-Hwei
MH
Hwu
Wuh-Liang
WL
D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D006008:Glycogen Storage Disease / Q000235:genetics*; D006801:Humans; D007223:Infant; D008107:Liver Diseases / Q000235:genetics*; D008297:Male; D009154:Mutation; D010764:Phosphorylase Kinase / Q000235:genetics*; D013624:Taiwan
D010764:Phosphorylase Kinase