AFG3L2 and progressive myoclonus epilepsy: With the identification of other patients with similar phenotypes we may be able to delineate the consistent and variable features of AFG3L2-related disorders and whether other mutations in AFG3L2 and SPG7 will only cause a spastic-ataxia-neuropathy syndrome or consistently produce an expanded “PME-spastic-ataxia-neuropathy” syndrome.