Glycogen accumulation disease type II, also known as Pompe’s disease, is an autosomal recessive disorder caused by defects in acid-α-glucosidase in lysosomes. The incidence of GSD II is about 1:40,000 in North America and Europe, and about 1:50,000 in Taiwan, China [1-3]; it is classified into infantile and late-onset forms according to the age of onset and tissues involved. The infantile form is more severe and often presents with early postnatal onset and rapid progression of myocardial hypertrophy, muscle weakness, feeding difficulties, and respiratory distress; the most common cause of childhood hypertrophic cardiomyopathy is GSD II. Patients with the infantile form develop myocardial hypertrophy and severe myocardial weakness in the first few months of life, progress rapidly, and often die of cardiopulmonary failure within 1-2 years of age. The late form often develops progressive muscle weakness and dyspnea in adolescence or adulthood, progresses slowly, and often dies of respiratory failure. The clinical manifestations of GSD type II patients are not specific, and GAA enzyme activity measurement is an important basis for its diagnosis. Although GAA is also expressed in peripheral blood leukocytes, the accuracy of the assay is affected by the interference of its isoenzymes maltoglucosidase and neutral glucosidase in neutrophils, and after 2004, acarbose was used to selectively inhibit MGA activity. After 2004, acarbose was used to selectively inhibit MGA activity, which significantly improved the accuracy and specificity of GAA determination. In 1999, recombinant GAA enzymes were used in clinical treatment, which significantly improved the survival time and quality of life of patients, but the efficacy of enzyme replacement therapy was limited in patients who had developed symptoms, and patients’ families had to bear the huge treatment costs. Even when receiving enzyme replacement therapy, the disease remains lethal [6]. To date, there are no reports of patients receiving enzyme replacement therapy in China. The high mortality rate of GSD II and the high cost of treatment have led to the need for some families to have another child, thus raising the need for prenatal diagnosis. Therefore, carrying out prenatal diagnosis of this disease is of great practical importance for the parents of patients to have normal children again.