RAB18 and Micro syndrome: 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).