Pontocerebellar Hypoplasia 11

Background and History: 

This recently reported hereditary condition has widespread neurological, eye, behavioral and brain abnormalities.

Clinical Correlations: 

The head is usually small at birth.  The ears are low-set.  There may be abnormal alignment of the eyes (strabismus) and there is often a visible defect in the pupil which is also visible inside the eyes.  Infants have poor eye contact.  There is general delay in neurological development with late achievement of walking, sitting, and talking.  Some individuals have seizures and there is unsteadiness (ataxia).  Muscle tone may be generally decreased (hypotonia) or increased (spasticity).  Speech may be slurred and swallowing difficulties have been reported in some patients.  Behavior abnormalities include signs of autism, and repetitive behavior.

MRI imaging shows generalized underdevelopment of brain structures.  Moderate to severe intellectual disability is nearly always present.


This condition results from mutations in both members of a specific pair of genes.  When both parents (who are clinically normal) carry a single copy of the mutation each of their children inherit a 25% risk of developing this disorder.

Diagnosis and Prognosis: 

None of the physical or neurological signs are unique to this disorder but their combination can suggest this condition.  Neurologists, ophthalmologists, and pediatricians may collaborate in the evaluation and care.  The smaller than normal head size at birth can be a clue to the diagnosis but this abnormality occurs in numerous conditions.  The neurological abnormalities do not seem to progress.  The impact on longevity is unknown.

No treatment has been reported.


Additional Information
Autosomal recessive