The major features of the condition include:
- developmental delay - delay in meeting motor milestones (eg sitting without support and crawling)
- muscle weakness
- early onset cataracts
- congenital cerebellar ataxia - a movement condition due to underdevelopment of the part of the brain controlling movement (cerebellum) causing unsteadiness and lack of coordination
- short stature (height)
- hypergonadotrophic hypogonadism (underactive sexual organs) causing a lack of development at puberty.
- learning disability - in some but not all children.
The extent to which people are affected by the condition varies between individuals.