Chiaratti et al. [126] previously showed that the oocyte-specific deletion of Mfn2 caused weight gain and glucose intolerance in the offspring; these findings were consistent with those of Garcia et al. [164] who reported that phenotypic abnormality (weight gain and glucose intolerance) in the offspring might relate to the disruption of functionality of MAMs in oocytes following the oocyte-specific deletion of Mfn2. The gene discussed is MFN2; the disease is Glucose intolerance.