AIFM1 and X-linked Charcot-Marie-Tooth disease type 4: In addition to the function as a caspase-independent apoptotic effector, AIF plays important roles in hearing and genetic metabolism and development and could lead to relative abnormalities, such as auditory neuropathy spectrum disorder (ANSD), mitochondrial encephalopathy, and Cowchock syndrome (Ghezzi et al., 2010; Rinaldi et al., 2012; Zong et al., 2015).