Testotoxicosis is due to

Testotoxicosis is an interesting disease that combines gain and loss of function. In this condition, an activating mutation of Gs a causes excess testosterone secretion and prepubeal sexual maturation. However, this mutation is temperature-sensitive and is active only at the relatively low temperature of the testes (33 degC). At 37 degC, the normal temperature of the rest of the body, it is replaced by loss of function, with the production of hypoparathyroidism and decreased responsiveness to TSH.