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The role of the CAG repeat androgen receptor polymorphism in andrology

M Zitzmann1

  • 1Institute of Reproductive Medicine, Universitätsklinikum Münster, Münster, Germany.

Frontiers of Hormone Research
|November 18, 2008
PubMed

Insights

The androgen receptor gene's CAG repeat polymorphism influences androgen effects, potentially causing hypogonadism even with normal testosterone. This genetic variation also affects testosterone replacement therapy outcomes in hypogonadal men.

Area of Science:

  • Genetics
  • Endocrinology
  • Molecular Biology

Background:

  • Androgen receptor (AR) dysfunction leads to androgen insensitivity or androgenicity.
  • The CAG repeat polymorphism in exon 1 of the AR gene, denoted as (CAG)n, modulates androgen-induced activities.
  • The length of the (CAG)n repeat inversely correlates with androgenic effects.

Purpose of the Study:

  • To investigate the clinical and pharmacogenetic implications of the (CAG)n polymorphism.
  • To understand how (CAG)n length affects androgenicity in eugonadal men.
  • To explore the role of (CAG)n in modulating testosterone treatment response.

Main Methods:

  • Analysis of the CAG repeat polymorphism in the androgen receptor gene.
  • Clinical assessment of androgenic phenotypes and psychological traits.
  • Retrospective analysis of testosterone treatment outcomes in hypogonadal men.

Main Results:

  • The (CAG)n polymorphism significantly modulates androgenicity in various tissues and psychological traits in eugonadal men.
  • Longer (CAG)n repeats are associated with attenuated androgenic effects.
  • The number of (CAG)n repeats influences the effectiveness of testosterone replacement therapy in hypogonadal men.

Conclusions:

  • The (CAG)n polymorphism is a key determinant of androgen action and clinical presentation.
  • This genetic variation has significant implications for diagnosing conditions like hypogonadism and for personalized testosterone therapy.

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