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GTR Home > Tests > Androgen receptor (AR) gene CAG triplet repeat test


This is a clinical test intended for Help: Diagnosis, Mutation Confirmation, Pre-symptomatic, Risk Assessment

Clinical summary


Imported from GeneReviews

Spinal and bulbar muscular atrophy (SBMA) is a gradually progressive neuromuscular disorder in which degeneration of lower motor neurons results in muscle weakness, muscle atrophy, and fasciculations. SBMA occurs only in males. Affected individuals often show gynecomastia, testicular atrophy, and reduced fertility as a result of mild androgen insensitivity.

Clinical features


Imported from Human Phenotype Ontology (HPO)

  • Dysphagia
  • Dysarthria
  • Fasciculations
  • Gynecomastia
  • Abnormality of the mouth
  • Peripheral neuropathy
  • Muscle spasm
  • Tremor
  • Sensory neuropathy
  • Testicular atrophy
  • Elevated circulating creatine kinase concentration
  • Limb muscle weakness
  • Hyporeflexia
  • Decreased fertility
  • Calf muscle hypertrophy
  • Bulbar palsy
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Conditions tested

Target population


Spinal Muscular Atrophy patients


  • Androgen receptor gene mutations in X-linked spinal and bulbar muscular atrophy. - PubMed ID: 2062380

Clinical validity


Not provided

Clinical utility


Establish or confirm diagnosis

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