Clinical features and genetic analysis of 5 cases of infantile-type glycogen storage disease type II: Case reports.

Objective: Clinical and genetic mutation analysis was performed on 5 infantile glycogen storage disease type II children in Chinese mainland.

Methods: Clinical data of 5 children with infantile-type glycogen storage disease type II due to the acidic α-glucosidase (GAA) gene variants diagnosed and treated at Hebei Provincial Children's Hospital from January 2018 to April 2020 were retrospectively analyzed.

Results: Among the 5 cases, 1 was female and 4 were male, and the age at first diagnosis was from 2 months to 7 months. The first symptoms of all 5 cases showed progressive muscle weakness, hypotonia, and motor developmental backwardness, and all of them had abnormally elevated creatine kinase, and the echocardiograms suggested different degrees of myocardial hypertrophy, with ejection fractions ranging from 44% to 67%. Analysis of GAA gene variations: all 5 cases were compound heterozygous, and a total of 12 variant loci were detected, of which c.2024_2026delACA, c.2853G > A, c.1124G > T, c.574G > A, c.2509C > T, and c.2013G > A were new mutations that had not been reported.

Followup: All 5 children died before 1 year of age, and the age of death ranged from 7 months to 11.5 months, with a mean survival time of 9.8 months.

Conclusion: Peripheral blood GAA gene testing and alpha-glucosidase enzyme activity testing is an effective method for diagnosing this disease.