In 2006, we reported the results of a study of 28 HF patients and 28 healthy controlsubjects in whom the median urinary hK1 specific amidase activity was significantlylower among HF patients [0.104 μM/(min · mg creatinine)] than amongcontrols [0.213 μM/(min · mg creatinine)] (p = 0.020)6. Here, HK1 is linked to hydrops fetalis.