[Puberty, fertility and chronic diseases].

The onset of puberty is the sum of complex and multifactorial mechanisms resulting from the action of both activating and inhibiting factors, leading to the maturation of the gonads and the ability to reproduce. Many contributors to pubertal development are involved in fat mass acquisition and their action is relayed through the hypothalamus. It is therefore easy to understand how chronic diseases can affect the development of puberty and fertility apart from the specific impact of their molecular alteration. We have chosen cystic fibrosis and chronic renal disease as examples of chronic disorders affecting puberty through distinct mechanisms. As drugs are undistinguishable from chronic diseases, we also describe the impact of corticosteroids and chemotherapy on reproductive function. Last, we describe the surveillance and care of pubertal delay and its consequences (growth and bone mineralization) of patients affected with chronic disorders during adolescence.