Neurogenetics and Multi-omics of Neuroinflammatory Diseases in Multiplex Families to Improve Patients Health

Background: Large genetic studies have found many common gene variants that raise the risk of multiple sclerosis, but they explain only part of the inherited risk. They also explain familial forms poorly. Rare variants with a strong effect may be shared within a family and go unnoticed in studies of unrelated people. Families with several affected members are well suited to finding them. NeuroDIP combines genetic, epigenetic (DNA methylation), and gene expression data from these families and links them to clinical information. Design: This is a cross-sectional, family-based study with a single visit and no follow-up. Comparing affected members with unaffected relatives from the same family helps limit the effect of ancestry and of factors that relatives share. Visit: At the hospital, participants give written consent and have a short physical examination. Patients also have a disability assessment (EDSS). The investigator draws a family tree and records medical history, treatments, lifestyle, and any previous brain MRI report. A blood sample is then drawn. The study does not change usual medical care. Relatives are invited through the affected family member and are contacted by the investigating centre. Samples and data: Samples and data carry a code, and names are kept only at the investigating centre. Samples are processed and stored in accredited biological resource centres. Research data are stored on secure servers in France and are not transferred outside the European Union. With participants' consent, coded data and samples may be used in future research on neuroinflammatory diseases, including deposit in the French MS registry (OFSEP). Results: Participants do not receive individual research results. The exception is an incidental finding with health consequences, and participants must agree to be informed of such a finding before they take part. Participants can ask for the overall results and may be invited to an optional information meeting for families. Funding: The study is funded by the Inserm Messidore 2024 call and by the ARSEP Foundation, and belongs to the NeuroDINet network on neuroinflammatory diseases.