Significant upregulation of miR-3200-3p, let-7g-3p, miR-486-3p, miR-652-5p, miR-133a-3p, miR-1-3p, mir-30c-5p, and miR-187-3p in the HF SAN was predicted to downregulate expression of the ion channels HCN1/4(If ), and SCN1A, SCN8A, SCN1B, SCN2B (INa), which are important for cardiomyocyte pacemaking and conduction. The gene discussed is SCN2B; the disease is hydrops fetalis.