The purpose of the study is to determine the frequency of mutations in the C9orf72 and SOD1 genes in the incident population of ALS patients followed in the FILSLAN centres

After obtaining free and informed consent for genetic characteristic tests, a blood sample will be taken during hospitalisation for diagnostic confirmation or during the quarterly multidisciplinary consultations planned for these patients in the classic follow-up set up within the ALS centres of the FILSLAN network if the genetic status is not already known. This sample will be integrated into the standard management of ALS patients, which includes a neurological examination and paraclinical explorations, including a biological assessment.

The patient will then be reviewed during the standard multidisciplinary follow-up consultations. Information to the patient on his or her C9orf72 or SOD1 genetic status will be included in the quarterly multidisciplinary consultations for the classic follow-up of ALS patients.

It should also be noted that the data (ALSFRS-r score, weight, FEV) collected during the 6 and 12 month consultations will be processed for the purposes of this research.

For patients included in the quarterly multidisciplinary consultations planned in the classic follow-up, if the genetic blood sample was taken during the initial hospitalisation for diagnosis, then it will not be repeated in the framework of the research. In this case, the genetic status of C9orf72 or SOD1 will be available at the inclusion visit and the patient will receive specific information about his or her genetic status.

Consent for the research will nevertheless be obtained in order to have the patient's agreement to the processing of their health data for the purposes of the research at inclusion, 6 months and 12 months.

Inclusion Criteria:

• Adult aged ≥ 18 years old
• ALS defined, probable or likely based on neurophysiological data according to Airlie House criteria (Brooks, 2000)
• Sporadic ALS or familial ALS defined by the existence of a case of ALS or FTD among first or second degree relatives of the patient included (Byrne et al, 2011).
• Participant affiliated to a social security scheme
• Free, informed and signed consent for the examination of the genetic characteristics of the participant

Exclusion Criteria:

• All conditions mimicking ALS including motor neuropathies with multiple conduction blocks and all cases of ALS that do not meet the criteria of the Airlie House classification.
• Patients who are cognitively incapable of signing the consent to participate in this study.

incident population of ALS patients followed in the FILSLAN centres.