The index clinical case involves acute alcoholic hepatitis complicated by profound hypophosphatemia due to phosphate diabetes, revealing a major production of both FGF23 C-terminal fraction (cFGF23) and bio-intact form (iFGF23, 39 751 RU/mL, N: 21–91; and 228.6 pg/mL, N: 22.7–93.1, respectively). This evidence concerns the gene FGF23 and hypophosphatemia.