Background: Glycogen storage disease II (GSD II) is caused by a deficiency of acid alpha-1,4-glucosidase and mutations in the GAA gene encoding this enzyme which are responsible for the pathogenesis of GSD II. Our goal was to determine the mutational spectrum in the GAA gene in Korean patients with GSD II.
Methods: Three patients with GSD II were recruited based on clinical and biochemical findings. Alpha-1,4-glucosidase activity was determined and the GAA gene sequence was analyzed by PCR and sequencing. We also collected information about the genotypes of Korean patients with GSD II from the medical literature.
Results: We identified six mutant alleles among the three GSD II patients: c.875A>G, c.1156C>T, c.1316T>A, c.1857C>G, and c2407_2412del7. c.1156C>T (Q386*) is a novel mutation. A comprehensive review of the literature revealed that a total of 29 mutant alleles, including 15 different mutations (10 missense, 3 deletion, and 2 nonsense mutations), were previously identified in 15 Korean GSD II patients. c.1316T>A (p.M439K) and c.1857C>G (p.S619R) were the most common mutations and accounted for 36.6% of the total mutant alleles.
Conclusions: We identified three GSD II patients and investigated the mutational spectrum in GAA in Korean patients with GSD II. Our results indicate that common mutations in the GAA gene vary according to ethnic background.
Keywords: GAA; Glycogen storage disease II; Korean; novel mutation.