A large-scale nationwide newborn screening program for Pompe disease in Taiwan: towards effective diagnosis and treatment.

The aim of this study was to: (a) analyze the results of a large-scale newborn screening program for Pompe disease, and (b) establish an effective diagnostic protocol to obtain immediate, valid diagnosis of infantile-onset Pompe disease (IOPD) to promote earlier treatment and better outcomes. In this study, 402,281 newborns were screened for Pompe disease from January 1, 2008 to May 1, 2012. Infants with low acid α-glucosidase (GAA) activity were referred to Taipei Veterans General Hospital for diagnostic confirmation. Physical examination, biochemical parameter (creatine kinase [CK], alanine transaminase, aspartate aminotransferase, and lactate dehydrogenase), and echocardiogram assessments were performed immediately to effectively differentiate IOPD from suspected late-onset Pompe disease (LOPD) or false-positive cases with pseudodeficiency mutation. Six infants with IOPD all presented with hypotonia, extremely low GAA enzyme activity (≤0.5 µmol/L/hr) in initial dried blood spot analysis, high CK (≥250 U/L), and high left ventricular mass index (LVMI, ≥80 g/m(2)). By analyzing these parameters, IOPD was distinguished effectively and immediately from suspected LOPD and false-positive cases. Except for the first referred case, five of the infants with IOPD received first-time enzyme replacement therapy (ERT) within 4 hr of admission and exhibited marked improvement. Our findings indicate that certain clinical manifestations (hypotonia, high CK, enlarged LVMI, and extremely low GAA enzyme activity in initial dried blood spot analysis) can help in the rapid and effective differentiation of patients with IOPD from other patient with low GAA activity. Such differentiation allows for the early application of first-time ERT and leads to better outcomes.