Mutations in genes encoding cytoskeletal proteins participate in the pathogenesis of familial dilated cardiomyopathy (fDCM). Additional factors including inflammatory reactions are believed to play a role in deterioration of left-ventricular function. An association of inflammatory fDCM with the HSPA1B 1267 A-->G polymorphism was identified. Since the HSPA1B 1267 A-->G polymorphism has been associated with autoimmune disorders, this finding might point to a pathogenetic role of (auto-) immune phenomena in distinct forms of familial DCM. HSPA1B 1267 A-->G is part of an extended DR3 haplotype explaining the strong association between both alleles. Recombinant haplotype mapping including neighboring genes might aid in identification and classification of susceptibility genes which in turn can point to the not yet identified causative agent.