A novel missense mutation in the thyroid hormone receptor beta gene in a kindred with resistance to thyroid hormone.

Direct sequencing of exon 9 of the thyroid hormone receptor beta (TRbeta) gene in a kindred with resistance to thyroid hormone revealed a substitution of threonine for methionine in codon 313 in one allele resulting from a T to C transition. This is a novel missense mutation that resides in one of the two mutational "hot-spot" regions of the TR beta gene suggesting altered triiodothyronine binding to this mutant receptor.