ADRB1 and familial dilated cardiomyopathy: Two years later the patient developed a symptomatic dilated cardiomyopathy (DCM) with a strongly reduced ejection fraction (23.5%) and functional anti-beta-1-adrenergic receptor antibodies (anti-β1AR-Ab) were found, his AOSD was by that time well controlled and other causes for DCM including cardiac amyloidosis were explored and ruled out.