OPA1 and Huntington disease: Concordantly, we showed abnormal mitochondrial dynamics in HD iPSC and NSC, in which the organelle assumes a spherical morphology (Facucho-Oliveira et al., 2007; Prigione et al., 2010; Zhang et al., 2011; Kelly et al., 2013) and lower mitochondrial levels of OPA1 in HD-iPSC and NSC, which may underlie altered mitochondrial morphology (Chen et al., 2016).