This is a recently described inherited disorder that limits horizontal eye movement (one type of ophthalmoplegia) and causes severe curvature of the spine (scoliosis).
Lack of side-to-side eye movements may be noted at birth or soon thereafter. Vertical eye motion is usually intact or only mildly impacted. Most patients have near normal vision. There may be fine nystagmus (sometimes called 'dancing eyes') and mild head shaking present. Turning of the head can mask the lack of horizontal motion in some individuals. In many patients the appearance of the eyes and their position appear normal to casual observers. Depth perception (stereoscopic vision) is often preserved to some extent.
bnormal curvature of the spine may be evident by 2 years of age and progressively worsens. MRI studies reveal mild abnormalities of the brainstem thought to reflect abnormal routing of nerve cell fibers accounting for the clinical findings. Mental development is normal.
This is an autosomal recessive disorder requiring two copies of a mutation (gene change). Many parents are related to each other but are clinically normal since they have only one copy of the mutation. However, such parents can expect that there is a 25% risk for each of their children to inherit this disorder.
The major health problem is the severe curvature of the spine and is often the presenting complaint to pediatricians and orthopedists. An ophthalmologist can diagnose the abnormal eye movements although they may be apparent to other observers. Surgery is required to stabilize the scoliosis where indicated. Longevity is not impacted but lifelong monitoring and physical therapy are recommended.