Clinical and Molecular Characterization of Infantile-Onset Pompe Disease in Mainland Chinese Patients: Identification of Two Common Mutations

We sought to understand the clinical course and molecular defects of infantile-onset Pompe disease (IOPD) among mainland Chinese patients.Twenty-five Chinese patients with IOPD were enrolled and clinical data were retrospectively reviewed. The entire coding region of the GAA gene was amplified by polymerase chain reaction and analyzed by direct sequencing.The median age at symptom onset was 3.4 months (range: 1.0-7.1 months) and 4.9 months (range: 2.7-8.3 months) at diagnosis. Only one patient received enzyme replacement therapy (ERT) and this child survived beyond the age of 2 years. Of the 24 patients not receiving ERT, all, but one patient, died at a median age of 8.3 months (range: 4.0-12.2 months). Thirteen novel and two common GAA mutations were identified in this study. The allelic frequency of c.2662G > T (p.Glu888X) was 23.1% in northern Chinese patients and 4.2% in southern Chinese patients, whereas the allelic frequency of c.1935C > A (p.Asp645Glu) was 20.8% in southern and 3.8% in northern Chinese patients.We identified the most common mutations in southern and northern Chinese patients with IOPD.