COL1A2 and hydrops fetalis: COL1A1, collagen alpha‐1(I) chain; COL1A2, collagen alpha‐2(I) chain; COL2A1, collagen alpha‐1(II) chain; COL3A1, collagen alpha‐1(III) chain; FGA, fibrinogen alpha chain; HF, heart failure; HFmrEF, heart failure with mid‐range ejection fraction; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; IGF, insulin‐like growth factor; UMOD, uromodulin.