The prevalence and diagnosis rates of Klinefelter syndrome: an Australian comparison

Objective: To determine the prevalence and diagnosis rates of Klinefelter syndrome (KS) in Victoria, Australia, and compare these to previous international findings. Design, setting and participants: A Victorian population-based descriptive study of all cytogenetic examinations resulting in a diagnosis of KS, including prenatal diagnoses from 1986 to 2006 and postnatal diagnoses from 1991 to 2006. Main outcome measures: Birth prevalence and diagnosis rates of KS. Results: The birth prevalence of KS in Victoria is estimated to be 223 per 100 000 males (95% CI, 195-254), with about 50% of cases remaining undiagnosed. Conclusions: KS may be occurring more frequently than has been reported previously, yet many cases remain undiagnosed. Our results highlight the need for increased awareness leading to timely detection.