Inclusion Criteria:  Twenty patients with ALS, including 10 patients with more than 5 years of disease progression without requiring respiratory support or gastrostomy feeding. All ALS patients will fulfill the following inclusion criteria: Aged 18 to 80 (inclusive) Possible, probable (clinically or laboratory) or definite ALS according to the revised version of the El Escorial World Federation of Neurology criteria (Brooks et al.,2000) Ten patients with Spinal-bulbar muscular atrophy (SBMA), aged 18 to 80 Ten healthy subjects: Control muscle specimens (deltoid) will be obtained from 10 adult patients (aged 18-80) without neuromuscular disease, undergoing shoulder surgery for local joint or bone disease in the local department of orthopaedic surgery