TUBB3 and congenital fibrosis of the extraocular muscles: TUBB3 harboring amino acid substitutions Arg262His, Glu410Lys, or Asp417His, which cause the more severe CFEOM-TUBB3 phenotypes, incorporate into microtubules, alter microtubule dynamics, and disrupt kinesin binding (Minoura et al. 2016; Niwa et al. 2013; Tischfield et al. 2010).