[Diseases caused by disorders of membrane transport: an overview]

Transport proteins such as channels and transporters play important roles in the maintenance of intracellular homeostasis. Genes for transport proteins have been cloned one after the other in recent years, and mutations in these transport protein genes have been identified in the pathogenesis of a number of hereditary diseases. These diseases include Liddle's syndrome, long QT syndrome, hyperkalemic periodic paralysis, cystic fibrosis, myotonia congenita, nephrogenic diabetes inspidus, glucose/galactose malabsorption, cystinuria, and Wilson's disease. Gene mutations in several receptors, including vasopressin V2 receptor, dihydropyridine receptor, and Ca2+ -sensing receptor, also cause disorders of membrane transport, leading to diseases. Further advances in basic science are expected to provide us with a detailed understanding of the abnormality in the 3rd/4th structure of mutated transport proteins.