Any familial isolated dilated cardiomyopathy in which the cause of the disease is a mutation in the LAMA4 gene. The disease is Monarch Disease Ontology id MONDO_0014095 (dilated cardiomyopathy 1JJ). Also known as: CMD1JJ, LAMA4 familial isolated dilated cardiomyopathy, cardiomyopathy, dilated, type 1Jj, dilated cardiomyopathy type 1JJ, familial isolated dilated cardiomyopathy caused by mutation in LAMA4.