Hypogonadism is a condition where sex hormone levels are low. In some people, this is linked to changes in genes that also affect brain development, which can influence learning, behaviour, and social skills. This MD research project aims to identify new gene changes associated with both hypogonadism and neurodevelopment, and UK Biobank genetic and clinical data will contribute to the MD thesis. We will analyse the genetic information of participants in a secure research environment and compare it with previous studies to understand how common these gene changes are in different populations. The findings are expected to improve understanding of the underlying causes of these conditions, support earlier and more accurate diagnosis, enhance care, and provide clearer guidance for families affected by hypogonadism and related neurodevelopmental features. All work will be carried out in accordance with relevant data governance policies.