A rare case report: atypical presentation of Klinefelter syndrome in a 24-year-old male at suburban tertiary care hospital in Nepal.

Klinefelter syndrome (KS) is the most common chromosomal condition affecting males, usually caused by the presence of an extra X chromosome (47, XXY). However, it often remains undiagnosed until adulthood. We report a unique case of a 24-year-old man whose primary concern was persistent nausea and vomiting, an atypical presenting complaint of Klinefelter syndrome. Further evaluation revealed typical features of KS, including infertility despite normal sexual desire, gradual enlargement of the breasts, tall stature, sparse facial and body hair, small testes, and learning difficulties. An uncommon finding in the patient was premature loss of dentition. Hormonal tests showed low testosterone levels with elevated gonadotropins and estradiol, consistent with primary hypogonadism, and karyotype analysis confirmed the diagnosis. This case highlights the wide spectrum of clinical features associated with Klinefelter syndrome, including both typical and atypical manifestations. This report emphasizes the need for increased awareness of such unusual presentations, for early diagnosis, and a multidisciplinary approach to management that can improve physical health, psychological well-being, and overall quality of life.