SPTBN2 and spinocerebellar ataxia type 5: Three heterozygous mutations of Sptbn2 cause Spinocerebellar Ataxia Type 5 (SCA5) in humans, a neurodegenerative disorder leading to impaired brain development and loss of motor coordination [21], while homozygous mutations result in a more severe childhood ataxia with cognitive impairment [19, 22], indicating an crucial role of Sptbn2 in neurodevelopment and cognition.