Amongst the established medical therapies for HFrEF, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), beta blockers, mineralocorticoid receptor antagonists (MRAs),ivabradine and newer agents such as angiotensin receptor-neprilysin inhibitor (ARNI) and sodium-glucose co-transporter 2 inhibitors (SGLT2i) have been shown in randomised controlled trials to improve symptoms, reduce HF hospitalisation, and decrease mortality (114). The gene discussed is ACE; the disease is hydrops fetalis.