The clinical features Cerebellar Ataxia, Mental Retardation, and Dysequilibrium Syndrome 2 include:
- Severe intellectual disability
- Cerebellar ataxia (lack of muscle coordination caused by dysfunction of a part of the brain called the cerebellum)
- Dysmetria (undershoot or overshoot of intended position with the hand, arm, leg, or eye)
- Dysarthria (unclear articulation of linguistically normal speech)
- Involuntary muscle contraction
- Inability to perform rapid alternating movements
- Delayed psychomotor and language development
- Degeneration of parts of the brain, visualized on MRI imaging
- Short stature
- Forward flexed head
- Abnormal outward curvature of the spine
- Abnormal sideway curvature of the spine
- Small hands and feet
- Rough facial features
- Short and wide nape
- Strabismus (‘crossed-eyes’)
The onset of this disease is in infancy.
Congenital hydrocephalus 3 has been reported in some individuals with autosomal recessive mutations in WDR81. The clinical features are apparent in utero and include:
- Hydrocephalus (accumulation of excess cerebrospinal fluid within the fluid containing cavities of the brain, which may lead to increased pressure in the head)
- Ventriculomegaly (enlargement of the fluid containing cavities of the brain)
- Hydranencephaly (missing right or left hemisphere of the brain)
- Degenerated or absent cerebellum (the part of the brain that coordinates movement)
- Holoprosencephaly (incomplete separation of the two hemispheres of the brain)
- Dandy-Walker malformation (abnormal development of the cerebellum)
- Macrocephaly (abnormally large head)
- Dysmorphic facial features
- Excess amniotic fluid in the amniotic sac, usually detected on ultrasound