Using Skin Cells to Study Amyotrophic Lateral Sclerosis

Inclusion criteria common to all 3 populations: * adults, both sexes * with written consent to participate in the study * affiliated to a social security scheme ALS patients : * patients with ALS according to the revised El Escorial criteria : * with a hereditary form of ALS, defined by the presence of a family history of ALS or by the demonstration of a pathogenic mutation in the patient or * with a juvenile form of the disease, defined by onset of symptoms at less than 30 years of age or * with a sporadic form of ALS Asymptomatic mutation carriers : \- Asymptomatic individuals who carry a mutation causing ALS but have not developed symptoms. Healthy subjects: * control individuals, taking into account male/female and close age matching Exclusion Criteria: * with a known skin disease (acne, atopic dermatitis, psoriasis, melanoma, skin carcinoma, rosacea, scabies; as referenced on http://dermato-info.fr/), which in the investigator's opinion constitutes a contraindication to skin biopsy * have a platelet count of less than 75,000/mm3 in a laboratory test less than 3 months old, * with a proven allergy to lidocaine or prilocaine, * Pregnant or breast-feeding women, or subjects under guardianship, curatorship or safeguard of justice. * Patient's condition which, in the opinion of the investigator, is incompatible with skin sampling or participation in the study. * Participation in a clinical trial (involving a drug) or other interventional research if this interferes with FIBRALS research.