congenital stationary night blindness 1B

Congenital stationary night blindness 1B is a non-progressive visual disorder that primarily affects the ability to see in low-light conditions. The condition is caused by mutations in the GRM6 gene, which plays an important role in retinal signaling. Affected individuals usually present in early childhood with symptoms such as difficulty seeing at night, though precise prevalence estimates are not available. Current descriptions emphasize that while the condition is present from birth, its impact on vision remains stable over time.

Characteristic clinical features include nyctalopia and congenital stationary night blindness, both of which are consistently observed. In addition, a subset of affected individuals may develop bone spicule pigmentation of the retina, myopia, and horizontal nystagmus, findings reported in 30-79% of cases. These visual challenges often lead to further ophthalmologic evaluation during early childhood. Not all individuals experience all features, and severity varies considerably.

This condition is caused by mutations in the GRM6 gene, which is essential for proper signal transmission in the retina. Congenital stationary night blindness 1B follows an autosomal recessive inheritance pattern, meaning that an individual must inherit two mutated copies—one from each parent—to be affected. This pattern implies that siblings of an affected individual have a 25% chance of being affected if both parents are carriers, and genetic counseling is recommended for families to understand these risks.

Currently, management focuses on supportive care and symptom management, as there are no specifically approved treatments for this condition. Patients are encouraged to have regular ophthalmologic evaluations and benefit from a multidisciplinary approach involving specialists to monitor vision and overall eye health. Regular surveillance is an essential part of long-term care, helping to identify potential complications early. In addition, genetic counseling is advised to help families understand the inheritance pattern and associated risks.

The clinical course of congenital stationary night blindness 1B is generally stable over time, with affected individuals experiencing lifelong challenges with night vision rather than a progressive decline. Outcomes can vary based on individual severity and access to specialized care, and modern management strategies have improved quality of life for many patients. That outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists familiar with this condition for ongoing support and guidance.