CBS and hydrops fetalis: Although the gene expression study in the pancreatic islet showed a lower expression for transcription factors involved in beta-cell differentiation, in particular, Pdx1, which was 50% decreased in CBS+/− (Table 2), the pancreas histological analysis showed a similar beta-cell mass and unchanged insulin/total pancreas ratio in the CBS+/− mice compared to the WT, after Met-HF treatment (Figure 4A,B).