Clinical Characteristics

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