Klinefelter syndrome is a genetic condition where males are born with an extra X chromosome (XXY instead of XY). This can lead to symptoms such as delayed development, infertility, reduced testosterone levels, and physical traits like taller stature, broader hips, and less facial and body hair2. Many individuals with Klinefelter syndrome may not realise they have it, as symptoms can be mild or overlooked until adulthood and often results in testosterone therapy