Klinefelter's syndrome





Introduction

Klinefelter's syndrome is associated with karyotype 47, XXY.

Clinical features

  • Often taller than average
  • Lack of secondary sexual characteristics
  • Small, firm testes
  • Infertile
  • Gynaecomastia - increased incidence of breast cancer
  • Elevated gonadotrophin levels but low testosterone

Diagnosis

Diagnosis is by karyotype (chromosomal analysis).