Inherited Metabolic Disorder
Inherited metabolic disorders (IMD) result from mutations of genes associated with metabolism, co factors, channels, carriers or receptors in metabolic pathways that are the basis of metabolic disorders of anabolic or catabolic pathways. These mutations could also be responsible for different types of biochemical abnormalities, including the accumulation of intermediate and/or bypass metabolites, or a deficiency of terminal metabolites, leading to metabolic crises, such as lactic acidosis, hyperammonemia syndrome and ketoacidosis. Genotype-phenotype correlations based on expression analysis of structural and functional mutations are gradually being recognized in different IMDs and subtypes of the disease, and >500 types of IMD have been identified so far. In all regions, it is reported that the overall incidence of neonatal with IMD is 1 in 1,000–2,500 newborns, while an estimated 16–20 million newborns are confirmed in China each year, indicating that effective and applicable measures are warranted due to the high-risk of infant IMD.