Identification and functional characterization of a novel thyrotropin receptor mutation (V87L) in a Chinese woman with subclinical hypothyroidism

Abstract

Abstract. The thyrotropin receptor (TSHR) gene has been defined as a highly mutable gene. Mutations in the TSHR gene result in either gain or loss of the receptor function. Subclinical hypothyroidism (SH) is a clinical condition defined as an elevated serum TSH level associated with normal free thyroxine and free triiodothyronine. Chronic autoimmune thyroiditis is the most frequent cause of subclinical hypothyroidism in adults. In rare cases, a loss-of-function mutation of TSHR is the cause of SH. In the present study, a novel TSHR mutation (V87L; confirmed to be a loss-of-function mutation) was identified in a 59-year-old Chinese woman, as the potential cause of the patient's subclinical hypothyroidism. The case may provide valuable insight into the etiology of SH.

Can inactivation mutation in the thyroid stimulating hormone receptor gene and hyperthyroidism coexist?: A case report

“…[4,6] The inactivation mutation of TSHR gene has a wide range of clinical and serological manifestations, ranging from severe non-autoimmune hypothyroidism to hyperthyroxemia with normal thyroid function. [7,8] The degree of TSH resistance depends on the severity of receptor function damage caused by mutation and the number of mut alleles. [9] Previous reports have shown that carriers of homozygous or compound heterozygous mutations are more likely to develop congenital hypothyroidism, while subjects with monoallelic heterozygous mutation in the TSHR gene may present with normal thyroid function or subclinical hypothyroidism.…”