In humans, TTPA mutations are responsible for AVED, a disorder previously known as familial isolated vitamin E deficiency (FIVE) (Schuelke 1993; Hoshino et al. 1999; Alex et al. 2000; Cellini et al. 2002; Mariotti et al. 2004; Bouhlal et al. 2008; Di Donato et al. 2010; Euch-Fayache et al. 2014; Elkamil et al. 2015; Zea Vera et al. 2021; Zhang et al. 2022). The gene discussed is TTPA; the disease is familial isolated deficiency of vitamin E.