Comparative analysis of plasma and PBMC proteomes identified Basigin (CD147) and phospholipid transfer protein C2CD2 as overlapping candidate markers across biological matrices.<h4>Discussion</h4>Although limited by sample size and the cross-sectional design, this exploratory study demonstrates the value of integrated, cross-matrix multi-omics profiling for identifying molecular patterns associated with advanced FXTAS. This evidence concerns the gene BSG and fragile X-associated tremor/ataxia syndrome.