Spinocerebellar ataxia type 36 (SCA36) is a subtype of autosomal dominant cerebellar ataxia type 1 (ADCA type 1; see this term) characterized by gait and limb ataxia, lower limb spasticity, dysarthria, muscle fasiculations, tongue atrophy and hyperreflexia.
The prevalence is unknown. SCA36 has been described in at least 14 Japanese and Spanish families in approximately 90 individuals.
SCA36 presents in adulthood with ataxic dysarthria, truncal ataxia, limb ataxia, general hyperreflexia and variably occurring lower limb spasticity. Motor neuron involvement occurs later in the disease course and manifests with fasciculations and atrophy of the skeletal muscles and tongue. Only mild cerebellar atrophy is reported. Sensorineural hearing loss may also be present in some.
SCA36 is due to a pathogenic heterozygous GGCCTG repeat expansion in intron 1 of the NOP56 gene (20p13).
SCA36 is inherited autosomal dominantly and genetic counseling is possible.
Last update: June 2014
- Dr Shinsuke FUJIOKA
- Dr Zbigniew WSZOLEK