PPP3CA and hydrops fetalis: Figure 2C presented a heatmap of clustering results (k = 2) and the PCA result showed a clear distribution between cluster A and cluster B (Figure 2D), suggesting that energy metabolism-related genes have potential diagnostic value for HF patients. Figure 2E presented a heatmap of 48 genes expression level between two clusters. The result of the boxplot showed that FOXO1, RXRA, CREB1, MAPK14, MEF2A,PPARD, FOXO3, EP300, CAMK3, MEF2C, MYBBP1A, NCOA1, PPP3CA, PPP3CC, PPRC1, TFAM, TFB2M were significant differential expressed between cluster A and cluster B (P < 0.05, Figure 2F).