AFG3L2 and spinocerebellar ataxia type 28: Although the presently described syndrome shares features with SCA28 and prominent spasticity clearly extends the phenotypic spectrum associated with AFG3L2 mutations, it appears different from SCA28 in several ways, specifically: 1) much earlier onset of symptoms, 2) spastic paraplegia as the earliest and predominant feature, and 3) presence of a peripheral neuropathy.