OBJECTIVES : Glycogen storage diseases are rare inherited autosomal disorders of carbohydrate metabolism. GSD 1a is caused by a deficiency in the G6P hydrolase activity that has potentially life threatening and chronically debilitating health effects. The aim of our study was to gain better understanding of the worldwide epidemiology of this rare disease.

METHODS : A systematic literature review was conducted. Extensive literature search was performed in five scientific databases and 26 grey literature sources, covering GSD 1a and its parent disease groups. PRISMA guideline was followed during the study selection process, two independent reviewers assessed the eligibility of articles based on predefined criteria. The relevant data from the included articles were extracted by using structured data extraction templates. Narrative synthesis of the research findings was performed.

RESULTS : In total, 3582 records were found through the systematic literature search. Despite the extensive search strategy, only 11 relevant studies were identified, from which six studies reported data on the prevalence of GSD 1a disease. The remaining articles published supportive evidence on the epidemiology of GSD 1 and GSD parent disease groups. The frequency of the GSD 1a disease ranged from 0.085/100,000 to 2.41/100,000 newborns. The data on the parent disease groups confirmed the rarity of the disease. The frequency of GSD 1 ranged from 0.25/100,000 to 3/100,000 newborns, while the frequency of GSD ranged from 0.4/100,000 to 10.3/100,000 newborns. The reported epidemiological measures and their calculations methods were highly heterogeneous.

CONCLUSIONS : Based on the results of the systematic literature review both GSD 1a and GSD 1 are rare diseases. However, the number of published studies with relevant evidence is very limited. More, well designed studies with standardized methodologies would be needed to precisely estimate the prevalence of the disease in the different geographical regions.