Inherited Metabolic Disorders (IMD) refer to a class of genetic diseases with metabolic defects. Most are due to the gene mutation that reduce or eliminate the functions of enzymes, receptors or carriers necessary for maintaining the normal metabolism of the body. This leads to the obstruction of normal metabolic pathways of some metabolites, the lack of terminal metabolites, and the Intermediate or bypass metabolite accumulation. And eventually leads to a series of clinical symptoms such as mental retardation and hypokinesia.