MKRN3 and central precocious puberty: It is estimated that in Western countries approximately 9% to 46% of familial CPP cases and 3% to 20% of sporadic CPP cases have identified MKRN3 mutations.[5] In 2013, MKRN3 mutations were first identified as one of the causative factors of CPP in 5 of 15 families.[7] Currently, 37 different loss-of-function mutations of MKRN3 gene have been published in 86 cases with CPP, including 14 frameshift defects, 19 missense mutations, and 4 nonsense mutations (Table 2).