The recent report of homozygosity for the MFN2 p.Arg707Trp mutation in three individuals with MSL (Sawyer et al., 2015) suggested the first germline Mendelian cause of the disorder, presenting a critical opportunity to further understanding of the underlying pathogenesis, however the pathology of the overgrown adipose tissue and the systemic metabolic consequences were not specifically studied. This evidence concerns the gene MFN2 and multiple symmetric lipomatosis.