Horizontal gaze palsy with progressive scoliosis

Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare autosomal recessive disease.

Clinical presentation

Abnormal horizontal gaze while normal vertical gaze and kyphoscoliosis. Horizontal gaze requires the action of ipsilateral abducent nerve and contralateral oculomotor nerve and mediated by the abducens nucleus. In this condition, there is congenital absence of the abducens nucleus results in abnormal horizontal gaze.

Pathology

Genetics

It is caused by mutation of ROBO3 gene on chromosome 11.

Radiographic features

MRI

• loss of facial colliculus due to absent abducens nucleus
• split pons sign
• butterfly medulla oblongata
• tenting of the 4 ventricle
• scoliotic deformity