CD79A and familial dilated cardiomyopathy: anti-tTG: anti-tissue transglutaminase; CD: celiac disease; DCM: dilated cardiomyopathy; ECG: electrocardiogram; ECHO: echocardiography; GFD: gluten-free diet; HF: heart failure; HLA-DQ2: human leukocyte antigen DQ2; IgA: immunoglobulin A; LVEF: left-ventricular ejection fraction; MPI: myocardial performance index; N: number; Tp-e: Tpeak-Tend; QTc: corrected QT.