X-linked retinoschisis is characterized by the abnormal schisis (splitting) of the retina’s neurosensory layers resulting in reduced visual acuity in affected men. Carrier females generally remain asymptomatic. Usually the condition is diagnosed in the first decade of life. It manifests with poor vision and reading difficulties. Other symptoms include night blindness, strabismus and nystagmus. In about half of the cases, peripheral vision is also affected in people with X-linked retinoschisis. Visual acuity remains stable until forties or fifties, when a significant deterioration in visual acuity occurs. In severe cases, vitreous hemorrhage and retinal detachment, which may lead to impaired vision or blindness, can be seen.
The prevalence of X-linked retinoschisis is estimated to range between 1:5,000-1:25,000 males worldwide.
The disease is caused by mutations on the RS1 gene, mutation spectrum reveals missense, nonsense, and splice site mutations, deletions, and insertions.
Indications for genetic testing:
1. Confirmation of clinical diagnosis
2. Carrier testing for at-risk family members
3. Genetic counseling
4. Prenatal diagnosis for known familial mutation