Inherited Metabolic Disorders (IMD) refers to a class of genetic diseases with metabolic defects. Most are due to gene mutation that reduces or lacks the functions of enzymes, receptors or carriers necessary to maintain the normal metabolism of the body, resulting in the obstruction of the normal metabolic pathways of some metabolites in the body, the lack of terminal metabolites, and the Intermediate or bypass metabolite accumulation. Eventually lead to a series of clinical symptoms such as mental retardation and hypokinesia.