Norrie disease

Norrie disease (also known as Norrie disease–pseudoglioma, atrophia bulborum hereditaria, or fetal iritis syndrome) is a rare X-linked recessive genetic disorder caused by mutations in the NDP gene located on chromosome Xp11.3. The NDP gene encodes norrin, a protein critical for normal vascular development of the retina and other tissues. The disease primarily affects the eyes, ears, and brain. The hallmark feature of Norrie disease is congenital blindness or severe visual impairment present at birth or developing in early infancy. Affected males typically develop bilateral retinal dysplasia, characterized by masses of immature retinal tissue (pseudoglioma) behind the lens, which may be visible as a white or grayish-yellow mass in the pupil (leukocoria). The retina often detaches, and the eyes may progressively shrink (phthisis bulbi). In addition to ocular involvement, approximately one-third of affected individuals develop progressive sensorineural hearing loss, typically beginning in childhood or early adulthood. Intellectual disability and developmental delays, including speech and behavioral difficulties, occur in a significant proportion of patients, estimated at 30–50%. There is currently no cure for Norrie disease. Management is supportive and multidisciplinary, involving ophthalmologic monitoring, hearing aids or cochlear implants for progressive hearing loss, and educational and developmental support services. Early surgical intervention for retinal detachment may be attempted in some cases but is often unsuccessful in restoring vision. Genetic counseling is important for carrier females, who are typically unaffected but may rarely show mild retinal abnormalities. Ongoing research into the norrin signaling pathway may offer future therapeutic targets.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Norrie disease