X-Linked Congenital Retinoschisis

Clinical characteristics: X-linked congenital retinoschisis (XLRS) is characterized by symmetric bilateral macular involvement with onset in the first decade of life, in some cases as early as age three months. Fundus examination shows areas of schisis (splitting of the nerve fiber layer of the retina) in the macula, sometimes giving the impression of a spoke wheel pattern. Schisis of the peripheral retina, predominantly inferotemporally, occurs in approximately 50% of individuals. Affected males typically have 20/60 to 20/120 vision. Visual acuity often deteriorates during the first and second decades of life but then remains relatively stable until the fifth or sixth decade.

Diagnosis/testing: The diagnosis of XLRS is established in a male proband with suggestive ophthalmologic findings and a hemizygous pathogenic variant in RS1 identified by molecular genetic testing.

Management: Treatment of manifestations: Management of refractive errors and amblyopia is per standard care. Ambylopia prevention therapy is indicated following surgical intervention for vitreous hemorrhage or retinal detachment or in instances of severe retinoschisis or hypermetropia.

Low-vision aids such as large-print textbooks; preferential seating in the front of the classroom; and use of handouts with high contrast. Surgery may be required to address the infrequent complications of vitreous hemorrhage and full-thickness retinal detachment.

Surveillance: Annual evaluation of children younger than age ten years by a pediatric ophthalmologist or retina specialist; patient education and close follow up may allow for early identification of refractive errors and treatment of vision-threatening complications (retinal detachment).

Agents/circumstances to avoid: Head trauma and high-contact sports to reduce risk of retinal detachment and vitreous hemorrhage.

Genetic counseling: XLRS is inherited in an X-linked manner. Heterozygous females have a 50% chance of transmitting the pathogenic variant in each pregnancy: males who inherit the pathogenic variant will be affected; females who inherit the pathogenic variant will be carriers and will nearly always have normal visual function. Affected males transmit the pathogenic variant to all of their daughters and none of their sons. Once the RS1 pathogenic variant in the family is known, carrier testing for at-risk female relatives, prenatal testing for pregnancies at increased risk, and preimplantation genetic testing are possible.