treatment and family planning. Student Health Service plays an important role in screening for

Abstract Background: Klinefelter syndrome (KS) is a common but under-recognised condition caused by an additional X chromosome in the phenotypic male. Clinical features are non-specific and thus many patients remain undiagnosed until adulthood. Persistent androgen deficiency in KS patients may result in cardiovascular complications and has fertility implications, thus warranting earlier detection. Subjects: Nine Chinese boys with karyotype-confirmed non-mosaic Klinefelter syndrome. Methods: Retrospective review of the clinical features at presentation, baseline hormonal investigations and the treatment response was conducted. Results: The mean age at presentation was 14.3 years old. Six patients (66.7%) were referred to us from Student Health Service. Six patients (66.7%) had height percentile more than the 50th height percentile. Only two (22.2%) had gynaecomastia. All had pubic hair bit with a testicular volume of <3 ml on each side. All had elevated gonadotropins but the degree of hypogonadism was variable. All patients reported morning erection after treatment. Conclusion: Our report is the first study reviewing KS in Chinese children. The clinico-hormonal features at presentation were similar to that in Western series, except, gynaecomastia was not as common. Early recognition of KS is important to facilitate timel