苯丙酮尿症(PKU)是一种严重的遗传性氨基酸代谢病。50年前,Fǒlling首先报道此病,并发现病人尿中含有大量的苯丙酮酸(phenylpyruvate),这是由于患者肝脏内的苯丙氨酸羟化酶(phenylalanine hydr-oxylase,简称PAH,EC 1.14.16.1)缺乏,苯丙氨酸不能转化为酪氨酸,苯丙氨酸便在体内累积。典型的PKU病人血中苯丙氨酸水平高于1200μM/l,结果一部分苯丙氨酸经代谢旁路转变为苯丙酮酸从尿中大量排出; Phenylketonuria (PKU) is a serious hereditary amino acid metabolism. Fifty years ago, Fǒlling first reported the disease and found that the patient’s urine contained a significant amount of phenylpyruvate due to the phenylalanine hydr-oxylase (PAH, EC 1.14 .16.1) is deficient, phenylalanine can not be converted to tyrosine, phenylalanine accumulates in the body. Phenylalanine levels in blood of a typical PKU patient are higher than 1200 μM / l, resulting in a partial excretion of phenylalanine from the urine by metabolic bypass into phenylpyruvate;