Hepatic glycogen storage disorders: what have we learned in recent years?

PURPOSE OF REVIEW: Glycogen storage disorders (GSDs) are inborn errors of metabolism with abnormal storage or utilization of glycogen. The present review focuses on recent advances in hepatic GSD types I, III and VI/IX, with emphasis on clinical aspects and treatment. RECENT FINDINGS: Evidence accumulates that poor metabolic control is a risk factor for the development of long-term complications, such as liver adenomas, low bone density/osteoporosis, and kidney disease in GSD I. However, mechanisms leading to these complications remain poorly understood and are being investigated. Molecular causes underlying neutropenia and neutrophil dysfunction in GSD I have been elucidated. Case series provide new insights into the natural course and outcome of GSD types VI and IX. For GSD III, a high protein/fat diet has been reported to improve (cardio)myopathy, but the beneficial effect of this dietary concept on muscle and liver disease manifestations needs to be further established in prospective studies. SUMMARY: Although further knowledge has been gained regarding pathophysiology, disease course, treatment, and complications of hepatic GSDs, more controlled prospective studies are needed to assess effects of different dietary and medical treatment options on long-term outcome and quality of life.

[Mitochondrial dysfunction in children with hepatic forms of glycogen storage disease].

AIM: The purpose of the study was to assess mitochondrial dysfunction severity in patients with hepatic forms of glycogen storage disease (GSD). PATIENTS AND METHODS: We examined 53 children with GSD in the dynamics. Distribution of children by disease types was: 1st group--children with GSD type I, 2nd group--children with GSD type III, 3rd group--children with GSD type VI and IX; comparison group consisted of 34 healthy children. Intracellular dehydrogenases activity: succinate dehydrogenase (SDH), glycerol-3-phosphate-dehydrogenase (GPDH). nicotinamideadenin-H-dehydrogenase (NADH-D) and lactatdehydrogenase (LDH) was measured using the quantitative cytochemical method in the peripheral lymphocytes. RESULTS: It was revealed decrease of SDH- (p < 0.001) and GPDH-activities (p < 0.001), along with increase of the NADH-D activity (p < 0.05) in all patients with GSD, (SDH/ NADH-D) index was decreased (p < 0.001). LDH activity was increased in groups 1 (p < 0.05) and 3 (p < 0.01), compared with comparison group. The most pronounced intracellular enzymes activity deviations were observed in children with GSD type I, that correspond to more severe clinical form of GSD. It was found strong correlation between intracellular enzymes activity and both hepatomegaly level (R = 0.867) and metabolic acidosis severity (R = 0.987). CONCLUSION: Our investigation revealed features of mitochondrial dysfunction in children with GSD, depending on the GSD type. Activities of lymphocytes enzymes correlates with the main disease severity parameters and can be used as an additional diagnostic criteria in children with hepatic form of GSD.