CAG repeat length in androgen receptor gene is not associated with amyotrophic lateral sclerosis.

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.