The U.S. Food and Drug Administration approved on Monday PTC Therapeutics, Inc.’s PTCT SEPHIENCE (sepiapterin) for children and adult patients with phenylketonuria (PKU).PTCT stock is on the move, climbing higher. Check the latest price here.PKU is a rare, inherited disorder that prevents the body from breaking down phenylalanine, an amino acid in protein-rich foods. PKU can lead to intellectual disability, seizures and behavioral problems.The approval includes broad labeling for hyperphenylalaninemia (HPA) ...