Exome Sequencing Uncovers Genetic Drivers of Multiple Sclerosis in a Multiplex Family

Background: Multiple Sclerosis (MS) is a chronic, autoimmune, multifactorial, and complex disorder of the central nervous system (CNS), affecting more than 2 million individuals globally. Genome-wide association studies (GWAS) have explained only a small fraction of its high heritability, highlighting the need for alternative approaches to identify rare genetic variants that contribute to its etiology. To address this, we performed whole-exome sequencing (WES) in a multi-affected family. Methods: WES was performed in a MS multigenerational family comprising two affected sisters, their two healthy brothers, and one affected son. Results: Bioinformatics analysis identified 47 co-segregating rare variants. Three missense variants in genes involved in inflammation, autoimmunity, and demyelinization were identified as the most promising candidates: c.443 C>T, p.Pro148Leu in the RTN4 gene, c.1678 T>G, p.Phe560Val in the JAK2 gene, and c.3449 A>G, p.Tyr1150Cys in the DUOX2 gene. Protein modeling and in silico tools suggest that the three selected variants may have a significant impact on protein function. Conclusions: We identified novel candidate genes for MS in a multiplex family, providing evidence for an oligogenic model of disease susceptibility. Further replication and functional studies are required to validate these preliminary results.