Resistance to thyroid hormone (RTH) is characterized by variable tissue hyporesponsiveness to thyroid hormone caused by mutations of thyroid hormone receptor β (TRβ) gene. We found a novel point mutation of the TRβ gene in a family (F123) with RTH, a transition of a guanine to adenine at nucleotide 1215, which replaced the normal Met-310 with Ile. This substitution was found in only one allele of affected family members. In vitro transcription and translation of this mutant TRβ demonstrated a 12-fold reduction of the affinity for triiodothyronine (T3) compared with the wild type TRβ. Thyroid function tests were similar to a previously reported RTH family (F99) who had a different mutation in the same codon (Thr 310).
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism