Onset is in the second year of life, when
bilateral corneal opacifications of the corneas (which eventually result in
severe visual impairment) and slowly progressive cerebellar anomalies with
variable spinocerebellar involvement begin. Patients may be mentally
delayed. In addition to the ocular findings (ptosis, corneal edema, pannus
and dystrophy with clouding and visual loss requiring penetrating
keratoplasty), the disorder may involve the face (triangular shape,
micrognathia, low-set ears with posterior angulation), the nervous system
(abnormal electroencephalogram, spinocerebellar degeneration, ataxia,
muscular hypertonia and spasticity, hemiparesis), and the musculoskeletal
system (lordosis, scoliosis, dislocation of the hips). Histologic anomalies
of nerves and muscles exist.