Does type I truly dominate hepatic glycogen storage diseases in Korea? A single center study

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±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.