Chen S.-T.HUEY-LING CHENYEN-HSUAN NIYIN-HSIU CHIENYUNG-MING JENGMEI-HWEI CHANGWUH-LIANG HWU2021-01-042021-01-0420091875-9572https://www.scopus.com/inward/record.uri?eid=2-s2.0-70449730793&doi=10.1016%2fS1875-9572%2809%2960068-1&partnerID=40&md5=74fe6ffb9e77ffd4913e926047429784https://scholars.lib.ntu.edu.tw/handle/123456789/537028X-linked liver glycogenosis (XLG), also known as glycogen storage disease type-IXa, is characterized by hepatomegaly, abnormal liver functions and growth retardation. It is caused by mutations in the PHKA2 gene that encodes the α-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. ? 2009 Taiwan Pediatric Association.[SDGs]SDG3phosphorylase kinase; phosphorylase kinase; abdominal distension; article; case report; child; echography; family; family history; gene mutation; glycogen storage disease; growth retardation; hepatomegaly; histopathology; human; human tissue; liver dysfunction; malaise; male; nucleotide sequence; pedigree analysis; preschool child; Taiwan; vertical transmission; X linked liver glycogenosis; genetics; glycogen storage disease; infant; liver disease; mutation; X chromosome linked disorder; Genetic Diseases, X-Linked; Glycogen Storage Disease; Humans; Infant; Liver Diseases; Male; Mutation; Phosphorylase Kinase; Taiwanjournal article10.1016/S1875-9572(09)60068-1198568672-s2.0-70449730793