RNA blots of P5 and P10 wt and Hq mutant skin hybridized with a probe specific for the 3′ end of the Aifm1 transcript showed a dramatic decrease of Aifm1 transcription at P5 and P10 (i.e., before and after the observed histological changes in the mutant HF; Fig. 5a). This evidence concerns the gene AIFM1 and hydrops fetalis.