A family of RTHb with XXXX mutation presenting occasional syndrome of inappropriate secretion of TSH.

@entity1 @entity2621 @entity71466 @entity11112 @entity5651
UNASSIGNED: The syndrome of inappropriate secretion of thyrotropin (SITSH) is a hallmark of resistance to thyroid hormone (RTH) due to mutations in the b isoform of the thyroid hormone receptor ( @entity11112 ). Here, we report on a family of RTH due to a @entity11112 mutation (RTHb) and presenting occasional SITSH. The proband was a 16 year-old @entity1 with a @entity5651 , detected at a school physical examination. She was initially diagnosed as having euthyroid @entity2621 because her thyroid function was normal with a positive anti-thyroglobulin antibody. Follow-up examinations resulted in mild SITSH on some occasions and euthyroid on the other occasions. A magnetic resonance imaging (MRI) revealed a normal pituitary gland. Because her mother also had mild SITSH, genetic analysis was performed and revealed a heterozygous point mutation in @entity11112 ( @entity71466 ). Previously, the @entity71466 had only been found in severe RTH cases with homozygous mutations or with an ectopic thyroid. Her mother with a heterozygous mutation showed variable RTH phenotype on T3 suppression testing. In conclusion, the prevalence of RTHb might be underestimated and occasional SITSH could also suggest RTHb. @entity11112 gene mutation is not always correlated with the RTH phenotype.
