苯丙酮尿症系由于编码苯丙氨酸羟化酶基因发生突变 ,导致苯丙氨酸和酪氨酸代谢障碍 ,可影响脑的发育 ,造成一系列神经系统损害。苯丙酮尿症脑损害可能存在以下的病理生理机制 :前额叶多巴胺能神经元功能障碍、髓鞘形成不良、兴奋性氨基酸受体异常、钙离子通道下调及Na+ ,K+ ATP酶活性降低 Phenylketonuria, due to a mutation in the gene encoding phenylalanine hydroxylase, leads to metabolic disorders of phenylalanine and tyrosine, can affect brain development and cause a series of neurological damage. Phenylketonuria brain damage may have the following pathophysiological mechanisms: dopaminergic neurons in the prefrontal dysfunction, myelination, excitatory amino acid receptor abnormalities, downregulation of calcium channels and Na +, K + ATPase activity decreased