Klinefelter syndrome is the most common sex chromosome anomaly, occurring in approximately 1 in 660 males, yet fewer than 30% of individuals are diagnosed. This low diagnosis rate is due to the wide variability in the phenotypic presentation of the condition. The failure to detect Klinefelter syndrome early can lead to significant health complications, including primary hypogonadism, infertility, and an elevated risk of various cancers and other systemic diseases. This study aimed to review the existing literature on Klinefelter syndrome, focusing on its clinical features and its management in the pediatric population. Articles were selected and reviewed from the PubMed database. Klinefelter syndrome manifests in a wide range of clinical presentations that vary based on the age of the patient and the severity of the disease. During infancy, most cases appear phenotypically normal, although extreme cases may present with conditions such as microphallus and undescended testes. As children approach puberty, the rate of diagnosis increases due to the insufficient development of typical pubertal features, such as virilization and muscle mass. Many cases remain undiagnosed until adulthood, usually when individuals seek medical help for infertility. Management strategies include testosterone replacement therapy, assisted reproductive techniques, and early intervention to address associated complications.
