Genotype and phenotype of CRB1 mutated Leber congenital amaurosis and early-onset retinal atrophy / 中华眼底病杂志

ABSTRACT

Objective:To investigate the relationship between genotype and phenotype in children with CRB1 mutated Leber congenital amaurosis (LCA) and early onset retinal dystrophy (EOSRD). Methods:A retrospective clinical study. From January 2013 to December 2019, 10 children with CRB1 mutated LCA/EOSRD were enrolled in the study. The patients were identified as CRB1 mutation by the second generation targeted capture sequencing, Sanger sequencing and the family segregation analysis. All children underwent electroretinogram (ERG) and fundus examination. At the same time, 6 cases were examined by optical coherence tomography (OCT); 1 case was examined by fluorescein fundus angiography (FFA), 7 cases were examined by wide-angle laser scanning ophthalmoscope (UWF SLO). Results:There were 6 cases of LCA and 4 cases of EOSRD in 10 patients with CRB1 gene mutations. The average age of first visit was 3.61 years old. The light and dark wave of ERG was flat in 6 cases, and decreased in 4 cases. A total of 19 pathogenic mutations were detected. There were 1 homozygous mutation and 9 compound heterozygous mutations. There were 4, 2 and 1 cases of "copper-coin" like, "salt and pepper" like and "osteocyte" like pigment changes in retina, 1 case of "crystalline pigment" change and 2 cases of macular pigment scar. In 7 cases of UWF SLO examination, different degrees of para-arteriolar pigment epithelium retention (PPRPE) were found in the middle and peripheral fundus. In 6 cases examined by OCT, the outer layer of retina atrophied and the band of ellipsoid disappeared. Symmetrical cystoid macular edema, splitting cystoid macular degeneration and adhesion of epi-macular membrane to optic disc and macular area were found in 1 case, respectively, the retinal structure was rough and thickened, and the fovea became thinner in 3 cases. In FFA examination, 1 case showed uveitis-like changes with late optic disc fluorescein staining, macular fluorescence accumulation, strong fluorescence diffusing along the blood vessels in each quadrant, peripheral PPRPE of "frost-branch" like strong fluorescence. Conclusion:The relationship between genotype and phenotype of CRB1 mutation is complex, and PPRPE is a common characteristic change.