The purpose of this research was to determine the phenotypic spectrum associated with phospholamban gene (PLN) mutations.Inheritance contributes to the development of dilated cardiomyopathy. Mutations in the gene encoding PLN have been associated with dilated cardiomyopathy characterized by early onset and the presence of lethal ventricular arrhythmias.We screened a cohort of 260 unrelated dilated cardiomyopathy patients from a tertiary care referral center for mutations in the PLN gene.Family history of cardiomyopathy was present in approximately one-half the individuals in this cohort. We identified 1 family with a deletion of arginine 14 in the PLN. Interestingly, unlike other individuals reported with the identical PLN mutation, these individuals were not diagnosed with dilated cardiomyopathy until their seventh decade when they were only mildly symptomatic with congestive heart failure.The identical PLN mutation can be associated with both mild and severe forms of dilated cardiomyopathy. Additionally, PLN mutations should be considered in late onset cardiomyopathy. (Genetics of Cardiovascular and Neuromuscular Disease; http://www.clinicaltrials.gov/ct/show/NCT00138931?order=1; NCT00138931)