Spinocerebellar ataxia-4 (SCA4) is an autosomal dominant neurologic disorder characterized by the onset of balance disturbances and gait and limb ataxia usually in the fourth decade, although earlier onset in the teens or twenties has been reported. There is evidence of genetic anticipation within families. The disorder is slowly progressive, and most patients eventually become wheelchair-bound. Additional features include hypometric or slow saccades, sensory or sensorimotor axonal peripheral neuropathy, dysarthria, and autonomic dysfunction, including orthostatic hypotension and problems with bowel or bladder control. More severely affected individuals have dysphagia and significant unintended weight loss, which may contribute to premature death. Brain imaging shows cerebellar atrophy (Wallenius et al., 2024).
For a discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (164400). [from
OMIM]