• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.2
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• pp.138-143
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• 2015

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.

• Journal of Yeungnam Medical Science
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• v.23 no.2
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• pp.252-257
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• 2006

Glycogen storage diseases are a heterogeneous group of metabolic disorder affecting multiple organ system: liver, skeletal muscle, heart and brain. Clinical features include: short status, hepatomegaly, hypoglycemia, dyslipidemia and rare involvement of the myocardium except in the case of type III, glycogen storage diseases with hypertrophic cardiomyopathy in adult, which is extremely rare. We treated a case of hypertrophic cardiomyopathy with hepatomegaly that was unknown etiology. The patient was diagnosed as having glycogen storage disease. This 46-year old women was transferred with dyspnea on exertion and abnormal LFTs. She was diagnosed with hypertrophic cardiomyopathy by echocardiography but there was no specific cause for hypertrophic cardiomyopathy. A liver biopsy was performed. The result showed glycogen storage disease possible type III, IV or IX. In conclusion, patients with hypertrophic cardiomyopathy of unknown etiology and abnormal LFTs should be evaluated for glycogen storage disease.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.3
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• pp.96-102
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• 2017

Glycogen storage disease type IX (GSD IX) is caused by deficiency of phosphorylase kinase which plays a role in breakdown of glycogen. Mutations in PHKA2 are the most common cause of GSD IX (GSD IXa). Clinical manifestations of GSD IXa include hepatomegaly, elevation of liver enzyme, growth retardation, fasting hypoglycemia, and fasting ketosis. However, the symptoms overlap with those of other types of GSDs. Here, we report Korean familial cases with GSD IXa whose diagnosis was confirmed by targeted exome sequencing. A 4-year old male patient was presented with hepatomegaly and persistently elevated liver enzyme. Liver biopsy revealed swollen hepatocyte filled with glycogen storage, suggesting GSDs. Targeted exome sequencing was performed for the differential molecular diagnosis of various types of GSDs. A hemizygous mutation in PHKA2 were detected by targeted exome sequencing and confirmed by Sanger sequencing: c.3632C>T (p.Thr121Met), which was previously reported. The familial genetic analysis revealed that his mother was heterozygous carrier of c.3632C>T mutation and his 28-month old brother had hemizygous mutation. His brother also had hepatomegaly and elevated liver enzyme. The hypoglycemia was prevented by frequent meals with complex carbohydrate, as well as cornstarch supplements. Their growth and development is in normal range. We suggest that targeted exome sequencing could be a useful diagnostic tool for the genetically heterogeneous and clinically indistinguishable GSDs. A precise molecular diagnosis of GSD can provide appropriate therapy and genetic counseling for the family.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.4
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• pp.239-247
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• 2014

Purpose: There are no studies of hepatic glycogen storage diseases (GSDs) other than type I and III in Korea. We aimed on investigating the characteristics of hepatic GSDs in Korea diagnosed and followed at a single center. Methods: We retrospectively analyzed patients who were diagnosed as GSD and followed at Samsung Medical Center from January, 1997 to December, 2013. Clinical manifestations, laboratory results, treatment, and prognosis were investigated. Results: Twenty-one patients were included in the study. The types of 17 patients were confirmed by enzyme activity tests and/or gene analysis. GSD Ia was diagnosed in 7 patients (33.3%), Ib in 1 patient (4.8%), III in 2 patients (9.5%), IV in 1 patient (4.8%), and IX in 6 patients (28.6%). Types other than GSD I constituted 52.9% (9/17) of the patients diagnosed with a specific type of hepatic GSD. The median age at presentation was 2 years. Hepatomegaly was observed in 95.2%, elevated liver transaminases in 90.5%, and hyperlactacidemia in 81.0% of the patients. The duration for follow-up was $77{\pm}62.0$ months. Uncooked corn starch was initiated in all the patients. No mortality was observed during the follow-up period, and liver transplantation was performed in 14.3%. Conclusion: Types other than GSD I comprised more than half of the patients diagnosed with a specific type of hepatic GSD. Clinical suspicion and thorough evaluation of hepatic GSDs in Korea should be focused not only on GSD I, but also on other types.