Herein, we describe the development and validation of a targeted NGS (tNGS) approach for the simultaneous detection of single-nucleotide changes and copy number variations (CNVs) in genes associated with HPA (PAH, GCH1, PTS, QDPR, PCBD1, DNAJC12) or useful for its differential diagnosis (SPR). This evidence concerns the gene QDPR and pulmonary arterial hypertension.