Mecp2-null male mice develop pronounced ataxia early in life (Chen et al., 2001; Guy et al., 2001), as do the Mecp2lox-Stop/Y mice (Guy et al., 2007) and the GABAergic-specific Mecp2 knockout mice (Chao et al., 2010). The gene discussed is MECP2; the disease is cerebellar ataxia.