Only a small number of genes have been linked to familial RCM, even though 30% of RCM sufferers have a family history of the condition, which is regarded as a primary disease of genetic origin (Table 2).41Examples of some of the genes affected include DCBLD2, which impairs vascular endothelial growth factor signaling leading to abnormal vascular development, which leads to desmin aggregates and disrupts intercalated discs. This evidence concerns the gene DCBLD2 and cardiomyopathy, familial restrictive, 1.