[Gender dysphoria in children and preadolescents: state of the art. Review and ethical assessment of therapeutic strategies].

Gender dysphoria (GD) can be defined as a persistent and intense experience of incongruence between biological sex and perceived gender identity, accompanied by significant distress and, frequently, an explicit desire to modify bodily characteristics. In the current scientific context, the study of GD is structured around several lines of research, including the possible existence of neurobiological differences between cisgender children/pre-adolescents (controls) and transgender individuals, alterations in the networks involved in body self-perception, and the potential contribution of biological factors - including genetic components - to the development of transsexuality, as has been demonstrated in some adult trans individuals, as well as to gender identity more broadly. In the clinical domain, interventions aimed at children and pre-adolescents with GD - primarily based on the administration of puberty blockers, followed in some cases by cross-sex hormone therapies and, exceptionally, surgical interventions - raise specific questions that go beyond those already identified in adult populations. These issues are particularly related to the role played by sex hormones in brain development during critical stages of neurodevelopment, as well as to the potential long-term effects on endocrine systems and reproductive function. The analysis of the available evidence on side effects, together with consideration of their potentially irreversible nature in certain cases, highlights the need for especially rigorous ethical evaluation. In this regard, the principle of primum non nocere assumes central importance, given that significant uncertainties remain as to whether the potential benefits of these interventions outweigh their inherent risks. Likewise, it is essential to ensure an interpretation of scientific data free from ideological bias, as well as to reinforce the requirement for a comprehensive diagnostic approach encompassing endocrinological, psychological, and social dimensions. This is further compounded by the critical issue of the validity of informed consent in minors, particularly in relation to their level of maturity. Finally, recent advances in the study of genetic bases and in the understanding of the neural networks involved in bodily self-perception open up the possibility of new therapeutic approaches, the exploration of which requires deeper and more systematic scientific development.