OPA1 and obesity due to melanocortin 4 receptor deficiency: YME1L1 plays a key role in mitochondrial morphology by mediating optic atrophy type 1 (OPA1) protein that is involved in mitochondrial fusion and remodeling, and is also believed to be associated with hereditary Spastic Paraplegia 7 disease, Autosomal Recessive disorder, obesity, and defective thermogenesis [73, 103–106].