The optic nerve connects the eye to the brain and carries visual signals from the retina that enables us to see. Consequently, any disease that damages this nerve can result in vision loss. A number of gene mutations lead to defects of optic nerve conduction of visual signals which may occur by itself or in association with other alterations in the brain or elsewhere such as in the disorder described here.
Optic nerve damage has been seen as early as 5 years of age but may be congenital in origin as abnormalities of the optic nerve was present in all 4 patients of the single family reported. Three of the 4 affected children also were nearsighted.
Other associated features in this family are: short stature, small heads, and brain atrophy. Children were slow to develop mentally and physically with unsteadiness (ataxia) and various abnormal physical movements. Speech likewise was slow to develop and all were intellectually delayed.
This is an autosomal recessive condition resulting from mutations in both members of a specific gene. The clinically normal parents carry one copy but there is a 25% chance that each child born to two such parents will inherit both copies and therefore have this disorder
The external physical findings are not specific and the diagnosis may be delayed until later in infancy when delayed mental development becomes apparent. Neurologists, ophthalmologists, and pediatricians may collaborate in the diagnosis and care of such infants. Visual handicaps are no doubt present and could be severe but have not been quantitated. MRIs of the brain can be helpful to the diagnosis.
No treatment has been reported. Nothing is known about longevity.