Any familial isolated dilated cardiomyopathy in which the cause of the disease is a mutation in the NEXN gene. The disease is dilated cardiomyopathy 1CC (MONDO_0013147, a Monarch Disease Ontology identifier). Also known as: CMD1CC, NEXN familial isolated dilated cardiomyopathy, cardiomyopathy, dilated, type 1Cc, dilated cardiomyopathy type 1CC, familial isolated dilated cardiomyopathy caused by mutation in NEXN.