ABCA4 mutations and phenotype of different hereditary retinopathies in 3 pedigrees

Abstract

Objective: To analyze the relationship between genotype and phenotype of different types of hereditary retinopahty caused by ABCA4 gene. Method: Three (3) pedigrees that carried mutations on ABCA4 gene as determined through the second generation sequencing technology were selected from the patients diagnosed with hereditary retinal disease in Ningxia Eye Hospital between Januaryand September 2016. The clinical features of patients and other family members of them were collected and analyzed with complete ophthalmic examinations including visual acuity, best corrected visual acuity, fundus examination, macular OCT, fundus fluorescein angiography and electroretinogram (ERG). The relationship between genotype and phenotype was analyzed. Results: All the 3 pedigrees were autosomal recessive families. Four mutations on ABCA4 gene were detected, the CRD pedigree and the RP pedigress carried a homozygous frameshift mutation respectively. The Stargardt pedigree carried two heterozygous mutations. The onset age of the patients were less than 10 years. The best corrected visual acuity was lower than 0.1 and the macular OCT indicated different levels of macular area atrophy, and the visual electrophysiological changes varied from completely normal to significantly reduced visual stem cell function in different cases. Conclusions: The patients with hereditary retinal disease that carried ABCA4 gene mutations were featured with characteristics of early onset age, rapid progress and severe visual impairment. The second generation sequencing technique has the advantages of rapidness and high efficiency in the diagnosis of hereditary retinal disease. (Chin J Ophthalmol, 2018, 54:775-781).