Analysis of Oculo-motor Deficiencies Associated With FMR1 Gene Expression (Genetic Abnormality Predisposing to a Neurodegenerative Disease)

FOR PATIENTS WITH PREMUTATION ON FMR1 GENE (30 patients expected): Inclusion criteria: * Male * \> or equal to 50 years old * Ally second or third degree with a child affected of "fragile X" * Not living far from Nantes so that visits to the Nantes hospital can be easy * Pre-mutation on FMR1 gene * Signed informed consent Exclusion criteria: * Female * \<50 years old * visual acuteness \< 1/10 * MATTIS dementia scale \<100 (normal:144) * Occurrence, shown by MRI (Magnetic Resonance Imaging), of a pathology either ischemic vascular or hemorrhagic or tumoral FOR PATIENTS WITHOUT PRE-MUTATION ON FMR1 GENE (10 patients expected): Inclusion criteria: * Male * \> or equal to 50 years old * Ally second or third degree with a child affected of "fragile X" * Not living far from Nantes so that visits to the Nantes hospital can be easy - Signed informed consent Exclusion criteria: * Female * \<50 years old * visual acuteness \< 1/10 * MATTIS dementia scale \<100 (normal:144) * Pre-mutation on FMR1 gene * Occurrence, shown by MRI, of a pathology either ischemic vascular or hemorrhagic or tumoral FOR PATIENTS WITH MULTI-SYSTEMATIZED ATROPHY (10 patients expected): Inclusion criteria: * Male * \> or equal to 50 years old * Not living far from Nantes so that visits to the Nantes hospital can be easy * "probable" diagnosis of multi-systematized atrophy * Signed informed consent Exclusion Criteria: * Female * \<50 years old * visual acuteness \< 1/10 * MATTIS dementia scale \<100 (normal:144) * Occurrence, shown by MRI, of a pathology either ischemic vascular or hemorrhagic or tumoral