AIFM1 and X-linked Charcot-Marie-Tooth disease type 4: This difference was probably due to the fact that AIFM1 could cause a variety of diseases, such as childhood cerebellar ataxia (Heimer et al., 2018), mitochondrial encephalomyopathy (Ghezzi et al., 2010), motor neuropathy (Diodato et al., 2016; Hu et al., 2017; Sancho et al., 2017), Cowchock syndrome (Rinaldi et al., 2012) and auditory neuropathy (Zong et al., 2015; Wang et al., 2020), with different severity and potential pathogenesis.