While several paternally imprinted genes have recently been implicated in hereditary and sporadic forms of CPP (e.g. DLK1, MKRN3) [23–25] in 3 out of the 4 familial CPP cases in the current cohort, it was the mother who reported a history of early menarche, suggesting maternal transmission. The gene discussed is MKRN3; the disease is central precocious puberty.