“…Phenotypes consistent with peroxisomal dysfunction, such as hypomyelination, developmental abnormalities and nystagmus, are also sometimes present in patients with DRP1 mutations [ 94 , 95 ]. Analysis of cells derived from these patients normally show major perturbations to the mitochondrial network reflecting a fission defect, including elongation of mitochondria and formation of a hyperfused network [ 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 ], or swollen ‘balloon-like’ mitochondria [ 102 , 103 , 104 ], with abnormal cristae structure [ 102 , 105 ]. Where peroxisomal morphology has been investigated, an elongated phenotype is often seen [ 96 , 100 , 101 , 103 , 104 ], which may be accompanied by constriction [ 95 ] ( Figure 3 ); however, in other patients, peroxisomes are morphologically normal [ 106 , 107 ].…”