Congenital Stationary Night Blindness (CSNB) is a rare, non-progressive inherited retinal disease (IRD) characterized by impaired night vision from childhood onwards. At Protheragen, we provide services spanning the full continuum from CSNB diagnostics to therapeutics development.
Overview of Congenital Stationary Night Blindness (CSNB)
Congenital Stationary Night Blindness (CSNB) is an inherited condition of the retina characterized by reduced or absent night vision since early childhood. It is strikingly diverse both clinically and genetically, meaning that there is a spectrum of observable traits, and the mutations responsible for them are numerous. Among the main types of CSNB are Riggs, Schubert-Bornschein, fundus albipunctatus, and Oguchi disease; each type has distinctive electrophysiological and clinical features. The latter groups differ in the type of inheritance, whether dominant or recessive, and autosomal or X-linked. The genetic diversity and complexity of CSNB highlight the requirement for more accurate testing and customized therapeutic strategies.

Fig. 1 Color fundus imaging. (Kim A. H.,
et al., 2022)
Pathogenesis of Congenital Stationary Night Blindness (CSNB)
Congenital stationary night blindness (CSNB) is caused by disruption of phototransduction and synaptic transmission in the retina. Important genes such as RHO which encodes for rhodopsin, result in the dysfunction of rod photoreceptors causing night blindness. GRM6, TRPM1, and NYX mutations block the glutamate signaling between photoreceptors and bipolar cells which create a breakdown in visual signal relay. The genetic mutations lead to characteristic abnormalities of the electroretinogram (ERG) including absent b waves in the dark adapted phase as well as electronegative low waveform oscillations which are unique indicators of CSNB. Understanding the molecular mechanisms that result from these alterations is essential in forming appropriate therapies.
Diagnostics Development for Congenital Stationary Night Blindness (CSNB)
- Genetic Testing
The developments in genetic testing technologies have changed the way CSNB is diagnosed. Mutations in the genes RHO, GRM6, TRPM1, NYX, and CACNA1F can now be causatively and definitively mapped through whole-exome sequencing and targeted gene panels. Genetic analysis goes beyond merely confirming the diagnosis. It sheds light on the specific genetic abnormalities which is pivotal for grasping how the disease operates and tailoring therapeutic approaches.
- Imaging Techniques
Techniques like spectral domain optical coherence tomography (SD-OCT) and short-wave autofluorescence (SW-AF) enable practitioners to obtain intricate pieces of structural information regarding the retina. SD-OCT can demonstrate the integrity of the ellipsoid zone (EZ) and the retinal architecture, whilst SW-AF can indicate increased or decreased autofluorescence, which reflects the health of the retina or reveals retinal pathology.
Therapeutics Development for Congenital Stationary Night Blindness (CSNB)
Gene Therapy
Gene therapy is one of the most promising therapeutics for CSNB. It involves the introduction of functional versions of the defective genes into the corresponding retinal cells which suffer from mutations. Genes responsible for causing these disorders are most often delivered via adeno-associated viral (AAV) vectors because they effectively transduce retinal cells without triggering much of an immune response. Animal models have shown structural restoration and enhanced ERG response with AAV gene augmentation.
Photoreceptor Transplantation
Another innovative therapeutic strategy includes photoreceptor transplantation. This method aims to transplant viable photoreceptor cells into the retina in place of the degenerated ones. Transplanted photoreceptors have been shown to make functional connections with bipolar and horizontal cells associated with significant enhancement of vision in experiments conducted on rats. For example, Gnat1−/− mice showed restored rod-mediated vision and enhanced navigation skills following rod photoreceptor transplantation.
Pharmacological Interventions
Pharmacological approaches consider modifying the phototransduction cascade or synaptic transmission to alleviate the consequences of the genetic disturbances. Small molecules and pharmaceutical agents targeting selective pathways implicated in CSNB are being studied. As a case in point, some compounds increasing glutamate signaling or stabilizing photoreceptor abnormalities may offer beneficial therapeutic prospects. While these pharmacological methods remain in the experimental stage, they may have potential for future usefulness.
Our Services
As a premier provider of research services, Protheragen offers integrated solutions for the study and therapeutics development of Congenital Stationary Night Blindness (CSNB). Our services include, but are not limited to, genetic profiling, sophisticated imaging, preclinical studies, as well as the development of therapeutics.
Disease Models
- GRM6 KO Models
- TRPM1 KO Models
- GPR179 KO Models
- GRM6 Mutation Models
- Rho Mutation Models
- CACNA1F KI Models
- LRIT3 Mutation
- SAG Mutation
Protheragen's preclinical research services for CSNB are designed to accelerate the development of novel therapies. We utilize a range of animal models, including mice and dogs, to study the pathophysiology of CSNB and evaluate the efficacy of therapeutic interventions. If you are interested in our services, please feel free to contact us.
References
- Kim, Angela H., et al. "Congenital stationary night blindness: clinical and genetic features." International Journal of Molecular Sciences 23.23 (2022): 14965.