[Diagnosis of thyroid hormone resistance by molecular biology]

The syndrome of thyroid hormone resistance is an inherited disease characterized by reduced thyroid hormone actions in the tissue. Clinically it is classified into two types: generalized resistance to thyroid hormone (GRTH) and pituitary resistance (PRTH). Recent advances in molecular biology have revealed a number of genetic abnormalities of thyroid hormone receptor beta (TR beta) in this disorder. The mutations of TR beta localized to two "hot spots" in the ligand binding domain. This article describes the basic procedures how to analyze TR beta genes and the functions of mutant TRs. Single stranded conformation polymorphism method is useful for screening and DNA sequencing is important to identify a TR gene mutation in patients. It is also necessary to construct the expression vector containing the mutant TR beta 1 gene to evaluate the mutant receptor functions.