TBX20 and familial dilated cardiomyopathy: Our results also confirm that TBX20 is a gene intolerant to haploinsufficiency, as it has been recently proposed by ClinGen10; this is relevant because new refinements of the American College of Medical Genetics criteria for specific conditions, such as DCM, are being proposed.21 In this sense, detecting a TBX20tv in a patient with DCM or LVNC should activate PVS1_Strong criteria and be considered likely pathogenic if it is also absent from controls and used predictively.