遗传代谢缺陷病(inborn errors of metabolism,IEM)是由于酶、载体或膜泵等缺陷而导致相应代谢途径阻断的一组疾病,是单基因遗传性疾病,目前已发现的IEM约有600种,单个病种的IEM人群发病率低,从数千分之一至数十万分之一,但总体发病率不低,新生儿筛查发现IEM发生率约1/2000。临床上IEM可以表现为神经系统、肌肉系统、肝脾系统、骨骼、血液、皮肤等单个或多个组织器官异常症状、体征。多数儿童期起病的IEM无特效治疗方法,预后 Inborn errors of metabolism (IEM) is a group of diseases that are blocked by corresponding metabolic pathways due to defects of enzymes, carriers or membrane pumps, and is a single-gene genetic disease. There are about 600 kinds of IEMs that have been discovered so far The incidence of IEM in a single disease was low, ranging from a few thousandths to one hundred millionths, but the overall prevalence was not low. Neonatal screening found an incidence of IEM of about 1 in 2,000. Clinical IEM can be manifested as nervous system, muscle system, liver and spleen system, bone, blood, skin and other single or multiple abnormal symptoms and signs of tissues and organs. Most of the onset of childhood IEM no specific treatment, prognosis