Advancing Neurogenetic Diagnoses Through Long-Read Sequencing

Inclusion Criteria: * All participants : * Participants affiliated with or beneficiaries of a social security scheme * Participants who speak French * Participants aged ≥ 6 and ≤ 60 years * For patients requiring a new sample: * Free and informed consent, signed by the parents or the holder of parental authority for patients under the age of 18 * Free and informed consent, signed by the patient's representative for adults under guardianship * Free and informed consent, signed by the adult patient * For diagnosed patients : • DeoxyriboNucleic Acid (DNA) sample from a subject carrying a nucleotide repeat expansion in one of the selected genes. * DNA available in sufficient quantity (5-10 µg) or patient agreeing to a blood draw from which DNA will be extracted. * DNA extraction methods known and validated by the steering committee (see paragraph 7). * For participants from undiagnosed families : o Index cases: • Patient affected by a neurological disease candidate for these repeats, for which genomic data did not reveal mutations or expansions in known genes. * Patient whose DNA is already available and whose extraction method is known and validated by the steering committee or patient whose DNA is not available but who agrees to a blood draw. * Patient willing to undergo a skin biopsy if not previously obtained. * Patient with no family members affected by any of the neurological diseases candidate for these repeats, i.e., genomic data do not reveal mutations or expansions in known genes. * Patient from a family in which at least one affected and one unaffected member agree to partici-pate in the study by providing a sample, or whose DNA is already available and extracted using a method known and validated by the steering committee. * For all related members of undiagnosed families who have agreed to participate: * Have at least two other family members who have agreed to participate in the study. * Agree to provide a blood sample or have DNA already available in sufficient quantity and extracted using a method known and validated by the steering committee. * Patient willing to undergo a skin biopsy if not previously obtained. * Be affected by a neurological disease candidate for these repeats, for which genomic data did not reveal mutations or expansions in known genes, or be unaffected and have had a neurological examination showing no signs related to any of the neurological diseases candidate for these repeats. * For controls : Participant for whom: * a consultation is scheduled at CHU Bordeaux for a reason other than a neurological disorder, has agreed to a neurological examination showing no signs of neurological disease, and has agreed to a blood draw and skin biopsy, or * the samples required for the study are already available in sufficient quantity in the CHU Bordeaux biobank and extracted using a method known and validated by the steering committee, or * accompanying a patient attending a consultation at CHU Bordeaux, showing no signs of neurologi-cal disease, and agreeing to a blood draw and skin biopsy, or whose samples are already available in sufficient quantity and extracted using a method known and validated by the steering committee. Exclusion Criteria: For all participants: • Refusal to participate in research: Refusal to provide informed consent or opposition to the use of these samples. * By the parents or the holder of parental authority for patients under the age of 18 * By the patient's representative for adults under guardianship * By the adult patient This opposition from the patient must be communicated to the site investigator within a maximum of one month after the information note has been sent. If the letter confirming consent is returned due to an incorrect address, the patient will not be included. * Degraded DNA or average size \< 30 kb