Night Blindness, Congenital Stationary, CSNB1H

Clinical Characteristics
Ocular Features: 

Night blindness is a feature of many pigmentary and other retinal disorders, most of which are progressive.  However, there is also a group of genetically heterogeneous disorders, with generally stable scotopic defects and without RPE changes, known as congenital stationary night blindness (CSNB).  At least 10 mutant genes are responsible with phenotypes so similar that genotyping is usually necessary to distinguish them.  All are caused by defects in visual signal transduction within rod photoreceptors or in defective photoreceptor-to-bipolar cell signaling with common ERG findings of reduced or absent b-waves and generally normal a-waves.  However, the photopic ERG can be abnormal to some degree as well and visual acuity may be subnormal.  In the pregenomic era, subtleties of ERG responses were frequently used in an attempt to distinguish different forms of CSNB.  Genotyping now enables classification with unprecedented precision.

Night blindness in this condition can be detected in early childhood and may be congenital.   Photophobia, reduced cone sensitivity. and mild dyschromatopsia may develop in midlife.  Peripheral field constriction can be demonstrated.  Visual acuity is near normal and there is no nystagmus or high myopia as reported for some other forms of CSNB.   

Systemic Features: 

There are no systemic abnormalities.


This is an autosomal recessive disorder resulting from homozygous or compound heterozygous mutations in the GNB3 gene (12p13.31).

Treatment Options: 

No effective treatment has been reported but the use of tinted lenses can enhance contrast and improve acuity.

Article Title: 


Vincent A, Audo I, Tavares E, Maynes JT, Tumber A, Wright T, Li S, Michiels C; GNB3 Consortium, Condroyer C, MacDonald H, Verdet R, Sahel JA, Hamel CP, Zeitz C, Heon E. Biallelic Mutations in GNB3 Cause a Unique Form of Autosomal-Recessive Congenital Stationary Night Blindness. Am J Hum Genet. 2016 May 5;98(5):1011-9.

PubMedID: 27063057