MFN2 and lipodystrophy: MFN2 R707W, uniquely among the many pathogenic MFN2 variants described to date (Zuchner 1993), causes major morbidity and mortality due to a combination of adipose overgrowth and metabolic complications of lipodystrophy (Rocha 2017, Sawyer 2015, Capel 2018, Carr 2015, Pareyson 2015).