Acid α-glucosidase; CLIR, Collaborative Laboratory Integrated Reports; CRIM, cross-reactive immunological material; DBS, dried blood spot; DMF, digital microfluidics; ECG, electrocardiogram; EF, ejection fraction; EMG, electromyography; ERT, enzyme replacement therapy; Enzyme replacement therapy; GAA, acid α-glucosidase; GMFM-88, Gross Motor Function Measure; Glc4, glucose tetrasaccharide; IOPD, infantile-onset Pompe disease; ITI, immunotolerance induction; LOPD, late-onset Pompe disease; LVMI, left ventricular max index; MFM-20, motor function measurement; MRC, Medical Research Council Scale; MRI, magnetic resonance imaging; MS/MS, tandem mass spectrometry; NBS, newborn screening; Newborn screening; PBMC, peripheral blood mononuclear cells; PD, Pompe disease; PPV, positive predictive value; Pompe disease; RUSP, Recommended Uniform Screening Panel; Tandem mass-spectrometry; Urinary tetrasaccharide; VUS, variants of uncertain significance.; nv, normal values; rhGAA, recombinant human GAA