Overview
Klinefelter’s syndrome is associated with the 47, XXY karyotype, where male patients have an additional X-chromosome. Symptoms can be subtle and many men may not even be aware they have the condition.
To help make sense of this chapter, it may be helpful to refer to Endocrine and Metabolic Physiology.
Epidemiology
- Klinefelter’s syndrome is the most common sex chromosome disorder
- Klinefelter’s syndrome often goes undiagnosed until adulthood
Presentation
Features can often be subtle:
- Infertility
- Small testes
- Decreased facial and pubic hair
- Reduced libido
- Tall build
- Gynaecomastia
Investigations
- FSH and LH:
- Elevated, usually FSH > LH
- Testosterone:
- Low
- Karyotyping:
- Diagnostic test
Management
Management is coordinated by a multidisciplinary team to monitor for long-term complications. Testosterone replacement is often used.
