Further, data regarding the ER pattern and idiopathic VF are somewhat unclear in the literature, as some authors identify ER syndrome and idiopathic VF as being two separate syndromes.87,95 Other evidence suggests that inheritance of the ER pattern is likely polygenic, with reports of mutations in SCN5A, CACNA1C, CACNB2B, and KCNJ8 present in patients with VF and an ER pattern on ECG.88 Finally, while there is anecdotal evidence of familial inheritance of the ER pattern, inheritance of a malignant phenotype has not been reported.88 This evidence concerns the gene KCNJ8 and ventricular fibrillation.