The clinical features of this disease, per organ system, include:
Central Nervous System
- Early developmental delay in motor milestones
- Intellectual disability
- Attention deficit hyperactivity syndrome
- Visual-motor perceptual dyspraxia
- Growth retardation and microcephaly
- Dystonia
- Dysarthria and severe linguistic delay
- Muscle cogwheel rigidity
- Brisk deep tendon reflexes
- Upgoing plantar responses
- Brain MRI: Thinning of the putamena and swelling of caudate heads
- PET scan: Hypometabolism of the putamina
The disease has a consistent phenotype among all the four affected siblings with neurodevelopmental delay from infancy and early-onset of cataract. Basal ganglia symptoms with dystonia and dysarthria becoming evident in early childhood.