[Dilated cardiomyopathy as part of familial dystrophia myotonica].

Dilated cardiomyopathy (DCM) is a condition characterized by non-ischaemic heart failure and is often hereditary. We present a family in which the proband had DCM in isolation while several relatives presented with myotonia, hypotonia, poly-hydramnion during pregnancy or a mental handicap. The disease presentation and subsequent genetic investigations were consistent with a diagnosis of dystrophia myotonica. This case presentation illustrate that DCM may be part of a systemic condition and that familial investigations may have important implications for correct diagnosis, treatment and counseling.