Phenylketonuria (PKU) is an autosomal recessive inborn error of Inherited Metabolic Disorders (IMDs) that lead to enzymatic deficiencies within specific metabolic pathways caused by genetic mutations in the phenylalanine hydroxylase (PAH) gene encoding phenylalanine hydroxylase [1–3], which results in the inability to convert Phe to tyrosine, leading to increased phenylalanine concentrations in the blood and central nervous system [4]. Here, PAH is linked to phenylketonuria.