TPP1 and cerebellar ataxia: Spasticity and CA were a common combination in 10 patients with variants in FBXO7, PLEKHG2, TPP1, ITPR1, KIF1A, and SPG7 genes; ataxia was also present in those with ITPR1, KIF1A, and SPG7 mutations; two probands with mutations in EXOSC3 suffered from early severe encephalopathy and CA, with progressive motor neuron signs after the first years of life.