The most common genetic alteration detected was a mutation in TNFRSF13B (TACI), with additional variants identified in DOCK8, RAG1, LRBA, PRF1, PSTPIP1, CECR1, PRKDC, and MRTFA. Logistic regression revealed a strong independent association between TACI mutations and ITP (OR: 46.5, p = 0.002), while no significant relationship was found with autoimmune cytopenias overall. This evidence concerns the gene TNFRSF13B and autoimmune thrombocytopenic purpura.