A novel TSHR gene mutation (Ile691Phe) in a Chinese family causing autosomal dominant non-autoimmune hyperthyroidism

Familial non-autoimmune hyperthyroidism is a rare autosomal dominant genetic disease resulting from activating mutations in the thyroid-stimulating hormone receptor (TSHR) gene. In this work a Chinese family with autosomal dominant non-autoimmune hyperthyroidism across four generations was collected. The strongest evidence for linkage in this study occurred on chromosome 14q24.2-31.3. By mutation scan of the TSHR gene located within the region of interest, a heterozygote substitution (A > T) at position 2071 of the TSHR was found, changing isoleucine 691 to phenylalanine. Our study identified the first germline mutation in the intracellular C-terminal domain of TSHR.