Nystagmus 1, Congenital, X-linked; NYS1
OMIM number: 310700
Comments closing date: 08/05/2026
Nystagmus 1, congenital, X-linked is a rare hereditary (genetic) condition caused by mutations in a gene called FRMD. When this gene is working, it is involved in development of neurons in the brain and retina (back of the eye). If a person is born with a mutation (also called “pathogenic variant”) in this gene, it can impact the eyes. The main feature of this condition is nystagmus, which is an involuntary, rapid eye movement of both eyes. This can lead to feelings of unsteadiness or balance issues, blurred vision, dizziness, sensitivity to light, and reduced vision particularly in the dark. There is also a significant psychological component to the condition, and affected people report increased feelings of social anxiety and reduced self-esteem as a result of the physical appearance of the condition. Certain professions and hobbies might be impossible. While both females and males can be affected, not all females with the mutation are affected and they might be more mild, although they can still have significant features of the condition. Contact lenses or glasses can help slow rapid eye movements which can improve vision. Some medications also can be helpful. Rarely, surgery can be performed to reposition the muscles around the eye.
