Spinocerebellar ataxia type 36 (nicknamed Asidan)

We report the phenotype of spinocerebellar ataxia type 36 (SCA36), which is a novel type of dominant cerebellar ataxia nicknamed as "Asidan," caused by the expansion of a hexanucleotide GGCCTG repeat in intron 1 of the nucleolar protein 56 (NOP56) gene. Age at the onset of ataxia was 53.1 (3.4) years (mean [SD]). Truncal ataxia was the most frequent initial symptom (100%), followed by ataxic dysarthria (100%), limb ataxia (93%), and general hyperreflexia (79%). Tongue fasciculation and subsequent atrophy were observed in 71% of the cases, especially in those of a longer duration. Skeletal muscle fasciculation and atrophy in the limbs and trunk were also observed in 57% of the cases. To our knowledge, we describe for the first time a unique clinical feature of Asidan (SCA36) - relatively pure cerebellar ataxia with progressive motor neuron involvement during the course of disease-that puts SCA36 at the crossroad of SCA and amyotrophic lateral sclerosis.