
        
Phenylalanine
            metabolic
            pathway
          
Phenylalanine
            is a primary amino acid that is abundant in dietary
            protein. It's main metabolic pathway yields the amino acid Tyrosine,
            which is involved in the production of Melanin pigments.
            Defects of enzymes responsbile for interconversion of
            metabolites in the pathway are the cause of three
            well-studied, single-gene Inborn Errors of Metabolism:
            Phenylketonuria (PKU), Albinism (Melanin
            deficiency), and Alkaptonuria (excess HA).