Spectrum analysis of gene mutations in retinitis pigmentosa and cone-rod dystrophy

AIM: To analyze the gene mutation spectrum of autosomal recessive retinitis pigmentosa(ARRP)pedigrees and cone-rod dystrophy(CORD)pedigrees in Ningxia region of China. METHODS:Totally 35 ARRP pedigrees and 18 CORD pedigrees were included in Ningxia Eye Hospital from September 2016 to February 2020. Peripheral venous blood samples of the proband were collected for targeted capture enrichment and high-throughput sequencing using a genetic retinal disease capture chip that contain 232 pathogenic genes. Online analysis software was used to predict the pathogenicity of suspicious gene variation, and Sanger sequencing was used to analyze the co-segregation of the family members. RESULTS: Totally 16 pathogenic genes were confirmed in 35 ARRP pedigrees, the mutations rate of RP1 gene was the highest, accounting for 14%(5/35), following were ABCA4, CRB1 and EYS gene, accounted for 11%(4/35); 18 CORD pedigrees carried 10 pathogenic genes. The mutation rate of ABCA4 gene was the highest, accounting for 28%(5/18), followed by ALMS1, PROM1, RPE65, USH2A gene, accounting for 11%(2/18). There were 5 co-exist disease-causing genes in ARRP and CORD pedigrees, which were ABCA4, CLN3, CRB1, PROM1, NRL, accounting for 42%(22/53).CONCLUSION: There are similarities and crossover in the phenotype of ARRP and CORD. The pathogenic genes were overlaped. The most common overlaping gene between the two diseases is ABCA4