hyperphenylalaninemia /hī′pərfen′ilal′əninē″mē·ə/ [Gk, hyper + (phenylalanine), haima, blood] , an abnormally high concentration of phenylalanine in the blood. This symptom may be the result of one of several defects in the metabolic process of breaking down phenylalanine. See also phenylketonuria.
