Sacubitril-valsartan was approved by the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) in 2015, based on the randomised controlled PARADIGM-HF trial (Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor with angiotensin-converting enzyme (ACE) inhibitor to Determine Impact on Global Mortality and Morbidity in HF) [3]. The gene discussed is ACE; the disease is hydrops fetalis.