STXBP1 and cerebellar ataxia: In ambulatory patients, gait patterns are described in a subset of cases, with three main patterns: ataxia or wide-based (STXBP1: 4/13 patients; IQSEC2: 4/8; MEF2C: 3/9; NTNG1: 1/2 and HNRNPH2: 1/1); dyspraxic (NTNG1: 1/2; GABBR2, HDAC4, ANXA11, KIF4B, RRN3, and JMJD1C: 1/1) and ataxic-dyspraxic gait (STXBP1: 1/13; KCNQ2: 1/6).