Electrophysiological characteristics and gene analysis of children with congenital stationary night blindness without fundus abnormalities

To analyze the electrophysiological and genetic examination results of children with congenital stationary night blindness (CSNB) without fundus abnormalities.

A retrospective study was conducted on 11 children diagnosed with CSNB in our department from August 2019 to March 2025. Their full-field electroretinogram (ffERG) and the results of genetic testing were analyzed.

Among the 11 patients, there were 10 males and 1 female, at a mean age of 7.5±2.1 years. In the optometry, 1 patient had hyperopia and the other had myopia, and all of them obtained a corrected visual acuity of 0.48±0.11 after wearing glasses. In fundus photography examination, except for the leopard pattern changes in high myopia, no obvious abnormalities were found in the remaining fundus. In ffERG examination for all patients, the amplitude of the a-wave of scotopic ERG 3.0/10.0 was normal or slightly to moderately decreased, the amplitude of the b-wave was decreased significantly, and the amplitude ratio of the b-wave to the a-wave was <1, showing a negative-phase wave, which belonged to the CSNB Schubert-Bornschein waveform. The results of genetic test revealed that all the 11 patients carried pathogenic mutations, including 6 cases with CACNA1F mutations, 2 cases with GPR179 mutations, 2 cases with NYX mutations, and 1 case with GRM6 mutation.

For children with normal fundus manifestations but corrected visual acuity lower than normal after wearing glasses, ffERG examination should be carried out as soon as possible to screen for CSNB, and a diagnosis should be made in combination with genetic testing. This is helpful for evaluating the heredity and prognosis of the disease, increasing the chance of early detection, and reducing excessive amblyopia training and treatment.