Since the implementation of NBS for congenital hypothyroidism (CH) and phenylketonuria (PKU) in the 1980s, followed by congenital adrenal hyperplasia (CAH) and glucose-6-phosphate dehydrogenase (G6PD) deficiency in the 2000s, the application of tandem mass spectrometry (MS/MS) to over 40 genetic metabolic diseases has revolutionized the field of NBS [2]. This evidence concerns the gene G6PD and phenylketonuria.