CYBA and hydrops fetalis: Through our one-gene and epistatic analyses, we concluded that genotypes which, in a particular context, induce higher oxidative stress (2-2 (HP), CT (MTHFR) and CC (CYBA)) and affect the indexes of iron (CC and HH (HFE)) or hematologic homeostasis (II (ACE)) are associated with an increased risk of developing HF.