The clinical features of 4 unrelated patients are highly variable. Onset of clinical signs is also variable and most are progressive. Several patients have presented in the first month of life with microcephaly and delayed motor development. Progressive cerebellar signs of ataxia with dystonia, dysphagia and motor signs from infancy has been seen. Other patients with cognitive deterioration and progressive neurologic deficits may present late in the first decade of life at which time ataxia, dysarthria, spasticity, and pyramidal signs nay also be noted. Dystonic and athetoid movements and intention tremor have been reported in some patients.
Brain MRIs in older individuals in the second decade of life reveal hypomyelinating leukodystrophy with thinning of the corpus callosum and cerebellar atrophy.