Among the patients with classical RTT, there was a higher frequency of spasticity‐dystonia (46.4%) and tremor‐ataxia (64.3%) in patients who were mutation positive compared with those who were mutation negative (spasticity‐dystonia [16.7%]; tremor‐ataxia [33.3%])The study showed that female patients who were MECP2 positive had more difficulties in walking, muscle tone, tremor, and ataxia. This evidence concerns the gene MECP2 and cerebellar ataxia.