Klinefelter Syndrome Prevalence

What proportion of people with Klinefelter syndrome are diagnosed prenatally, at birth, or later in life and how does that affect prevalence estimates?

Klinefelter syndrome (KS, typically 47,XXY) is relatively common at birth—roughly 1 in 500–1,000 male births—yet the majority of affected males go undiagnosed until adolescence or adulthood, causing l...