Because of the clinical overlap between ARCL3A and WARBM, we carried out screening for ALDH18A1 mutations in an additional 51 families with a WARBM phenotype but in whom there were no identified mutations in the known disease genes, RAB3GAP1, RAB3GAP2, RAB18, or TBC1D20. This cohort is detailed in Handley et al. (2013). The gene discussed is TBC1D20; the disease is Warburg micro syndrome.