There are currently no studies on how HF in T1D increases cardiovascular (CV) risk and overall mortality; on the other hand, the role of HF as a major contributor to CV morbidity and mortality in type 2 diabetes (T2D) has been highlighted by several clinical trials on the efficacy of sodium–glucose cotransporter-2 inhibitors (SGLT2-is) in CV prevention [11,12,13,14,19]. The gene discussed is SLC5A2; the disease is hydrops fetalis.