Congenital motor nystagmus is caused by involuntary ocular oscillations (eye movements). It is not yet known whether the problem lies in the function of the eye or the function of the brain.
Genetically, the problem may be inherited in an autosomal dominant, autosomal recessive or X-linked dominant or X-linked recessive manner and it has been suggested that at least 4 genes are associated with congenital motor nystagmus. This means that mutations in any of these genes could cause the problem. However, not all cases of early onset nystagmus are thought to be genetic.
I do not know whether the nystagmus you have described could be contributing to your son’s development. To get specialist advice about your son it would be best to see your doctor and ask to be referred to a paediatric neurologist and/or ophthalmologist.
Dr Jane Fleming