Decreased leptin levels have been linked to altered mitochondrial metabolism of the adipose tissue and previously described in patients with multiple symmetrical lipomatosis (MSL) caused by mutant mitofusin 2 (Rocha et al, 2017) and mouse models of primary adipose tissue pathology (Vernochet et al, 2012; Becker et al, 2018). This evidence concerns the gene MFN2 and multiple symmetric lipomatosis.