Background: Epidemiological and clinical studies show higher prevalence of amyotrophic lateral sclerosis (ALS) in males than in females and more severe lesions in androgen receptor (AR)-expressing tissues. The AR gene contains a polymorphic CAG trinucleotide repeat, whose expansion over a certain threshold is toxic to motor neurons, causing spinal and bulbar muscular atrophy (SBMA).
Purpose and methods: We tested the hypothesis that the AR CAG repeat linked to SBMA is a risk factor for ALS. We analyzed AR CAG expansions in 336 patients with ALS and 100 controls.
Results: We found a negative association of AR CAG expansions with ALS susceptibility, clinical presentation, and survival.
Conclusions: Our findings do not support a role of the AR CAG repeat length in ALS.
© 2012 The Author(s) European Journal of Neurology © 2012 EFNS.