SMPD1 and mucopolysaccharidosis type 1: In the present study, we aimed to design and evaluate both the clinical and diagnostic validity of a semi-automated and comprehensive sequencing assay based on a targeted NGS (tNGS) panel (hereafter referred to as NBS_LSDs) to screen variants in six genes (GBA, GAA, SMPD1, IDUA1, GLA, GALC) whose mutations are responsible for a set of LSDs (MPSI, Pompe, Krabbe, Fabry, Gaucher, and Niemann Pick A-B diseases) that are candidates for inclusion in NBS programs.