Two families with three offspring having this rare hereditary disorder have been reported. It is a condition of congenital brain maldevelopment with abnormal eye movements, delayed development, and abnormal curvature of the spine.
Abnormal eye movements are evident at birth. The eyes are unable to move horizontally while vertical eye movements are intact. Infants are 'floppy' and neurological development is slow with significant delay in achievement of milestones. Intellectual disabilities are evident. Walking can be unsteady but may also be normal. Abnormal curvature of the upper spine has been detected as early as 4 years of age. This is progressive and can cause difficulties in breathing that requires spinal surgery by the second decade of life.
Imaging (MRIs) of the brain shows a variety of abnormalities most of which suggest incomplete or faulty crossing of nerve fibers from one side of the brain to the other. Certain brain structures are not fully developed and some are absent.
This condition results from specific mutations in both members of a gene pair. Parents who carry one copy are normal but when both carry the single mutation they confer a 25% risk to each of their children to develop this disorder.
Since the abnormal eye movements are present at birth, an ophthalmologist should do a complete eye examination. Pediatricians and neurologists should evaluate the general neurologic status and general 'floppiness' is reason to do a full neurological evaluation. A radiological evaluation of the spine should be done in such infants to look for early abnormalities of curvature.
Physical could be helpful beginning as soon as the diagnosis is suspected. No treatment for the abnormal eye movements has been reported. The level of vision has not been reported. Nothing is known about longevity.