The human Bosley-Salih-Alorainy (see OMIM reference no. 601536) and Athabascan brainstem dysgenesiss syndromes resulting from HOXA1 loss-of-function mutations also have variable phenotypes among affected individuals, although horizontal gaze palsy and bilateral deafness have been considered the primary features (Bosley et al., 2008). The gene discussed is HOXA1; the disease is deafness.