Clinical and Genetic Characteristics of Korean Congenital Stationary Night Blindness Patients

Abstract

In this study, we investigated the clinical and genetic characteristics of 19 Korean patients with congenital stationary night blindness (CSNB) at two tertiary hospitals. Clinical evaluations, including fundus photography, spectral-domain optical coherence tomography, and electroretinography, were performed. Genetic analyses were conducted using targeted panel sequencing or whole exome sequencing. The median age was 5 (3–21) years at the initial examination, 2 (1–8) years at symptom onset, and 11 (5–28) years during the final visit. Genetic mutations were identified as CNGB1 and GNAT1 for the Riggs type (n = 2), TRPM1 and NYX for the complete type (n = 3), and CACNA1F (n = 14) for the incomplete type. Three novel variants were identified, and best-corrected visual acuity (BCVA) and spherical equivalents (SE) were related to each type of CSNB. The Riggs and TRPM1 complete types presented mild myopia and good BCVA without strabismus and nystagmus, whereas the NYX complete and incomplete types showed mixed SE and poor BCVA with strabismus and nystagmus. This is the first case series of Korean patients with CSNB, and further studies with a larger number of subjects should be conducted to correlate the clinical and genetic aspects of CSNB.

Precision Medicine through Next-Generation Sequencing in Inherited Eye Diseases in a Korean Cohort

“…The other 59 patients (39.6%) remained unsolved after targeted NGS. Among solved 90 patients, 25 patients were previously reported by our group [ 12 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. The molecular diagnostic rate was higher in patients with family history than in singleton cases (86.8% vs. 51.4%, p < 0.001).…”

Ocular findings and genomics of X-linked recessive disorders: A review

“…X-linked CSNB may be caused by mutations in the NYX (OMIM # 300278) and CACNA1F (OMIM # 300110) genes. [ 103 102 103 104 105 106 107 108 109 110 111 ] NYX gene mutations may be responsible for nearly half of the X-linked CSNB, leading to the complete form or CSNB1A. The product of this gene is a 476-amino-acid polypeptide expressed in the eye during all stages of postnatal retinal development and belonging to a small leucine-rich proteoglycan family of proteins.…”

“…The product of this gene is a 476-amino-acid polypeptide expressed in the eye during all stages of postnatal retinal development and belonging to a small leucine-rich proteoglycan family of proteins. [ 103 104 105 106 107 108 109 110 111 ] CACNA1F gene mutations may explain more than half of the X-linked CSNB and result in CSNB2A. [ 103 104 105 106 107 108 109 110 111 ] CACNA1F encodes an alpha-1 subunit of the voltage-dependent calcium channel which is a multipass transmembrane protein mediating the influx of calcium ions into the cell.…”

“…[ 103 104 105 106 107 108 109 110 111 ] CACNA1F gene mutations may explain more than half of the X-linked CSNB and result in CSNB2A. [ 103 104 105 106 107 108 109 110 111 ] CACNA1F encodes an alpha-1 subunit of the voltage-dependent calcium channel which is a multipass transmembrane protein mediating the influx of calcium ions into the cell. [ 111 ]…”

“…Cone function might be impacted to some degree and mild dyschromatopsia may be an associated finding. [ 103 104 105 106 107 108 109 110 111 ] Based on ERG, individuals with X-linked CSNB are the Schubert–Bornschein type with scotopic b-wave amplitudes being reduced in response to bright flashes after dark adaptation. [ 103 104 105 106 107 108 109 110 111 ]…”