Klinefelter's Syndrome

Exam Cram

• Klinefelter's is a syndrome defined by its chromosones of XXY, resulting in 

• Pathophysiology: loss of testicular Leydig ability to process testosterone into DHT 

• Presentation: male, poor virilisation (puberty progression), tall

• Diagnosis: chromosonal analysis

Outline

Background

• Pathophysiology: loss of testicular Leydig ability to process testosterone into DHT 

Assessment

History

Examination

Investigations

Diagnosis

Diagnostic criteria: chromosonal analysis

Differentials: 

Kallman's Syndrome:

• Loss of sense of smell

• XY or XX

• Male or female

• Hypog hypog

Androgen insensitivity syndrome

• Bilateral hernias,

• Tall

• XY

• Female external, male internal

Turner's Syndrome

• Short

• X0

• Female

Management 

Infertility

• Intracytoplasmic sperm injection achieves fertilisation rate of 50%. 

• Issue is male azoospermia.

References and Resources

Written in 2025