Pediatric Gastroenterology, Hepatology & Nutrition  2015;18(2):138-143

doi:10.5223/pghn.2015.18.2.138

Clinical, Biochemical, and Genetic Characterization of Glycogen Storage Type IX in a Child with Asymptomatic Hepatomegaly.

Jung Ah KIM 1 ; Ja Hye KIM ; Beom Hee LEE ; Gu Hwan KIM ; Yoon S SHIN ; Han Wook YOO ; Kyung Mo KIM

Affiliations

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Keywords

Glycogen storage disease; Glycogen storage disease type IX; Phosphorylase b kinase 2; Phosphorylase kinase; Hepatomegaly

Country

Republic of Korea

Language

English

Abstract

Glycogen storage disease type IX (GSD IX) is caused by a defect in phosphorylase b kinase (PhK) that results from mutations in the PHKA2, PHKB, and PHKG2 genes. Patients usually manifest recurrent ketotic hypoglycemia with growth delay, but some may present simple hepatomegaly. Although GSD IX is one of the most common causes of GSDs, its biochemical and genetic diagnosis has been problematic due to its rarity, phenotypic overlap with other types of GSDs, and genetic heterogeneities. In our report, a 22-month-old boy with GSD IX is described. No other manifestations were evident except for hepatomegaly. His growth and development also have been proceeding normally. Diagnosed was made by histologic examination, an enzyme assay, and genetic testing with known c.3210_3212del (p.Arg1070del) mutation in PHKA2 gene.