| A rare genetic neurological disease due to SPTBN2 (spectrin beta, non-erythrocytic 2) mutations. The disease has characteristics of global development delay in infancy, followed by childhood-onset gait ataxia with limb dysmetria and dysdiadochokinesia, mild to severe intellectual disability, development of cerebellar atrophy and abnormal eye movements (including a convergent squint, hypometric saccades, jerky pursuit movements and incomplete range of movement). Caused by homozygous mutation in the SPTBN2 gene on chromosome 11q13. |