RESUMO
Background Retinitis pigmentosa (RP) is a monogenic inheritance and blinding disease of fundus oculi.There is not an effective therapeutic method now.Objective This work was to identify the mutations of RP1 gene in Chinese RP patients in Ningxia area and to explore the potential interactions in the pathogenesis of RP.Methods The periphery blood of 3-5 ml was collected from 110 individuals with RP(35 ADRP and 75SRP)and 100 normal controls in Ningxia area.Polymerase chain reaction (PCR) and direct DNA sequencing were used to screening the sequence alterations in the entire coding region and splice sites of RP1 gene.Multivariate analysis and two web-based programs( PolyPhen and SIFT) were used to analyze the results.Results Eleven mutation locus were detected in the exon 4 of RP1 gene including two novel sequence variants:p.Lys1152Lys without a higher mutation rate in comparison with normal control group(x2 =9.12 P＜0.01 ),but c.* 247A＞C with a higher mutation rate in comparison with normal control group(x2 =12.77,P＜0.01 ) and c.* 247A＞C mutation was thought to be correlated with RP( r=1.11,P＜0.05 ).The other ten mutation locus were reported as single nucleotide polymorphisms (SNP).The mutation rate of p.Gln1725Gln was found to be higher in the RP patients than the normal controls (x2 =42.09,P＜0.01 ),but no the significant correlation was seen between the pathogenesis of RP and mutation of p.Gln1725Gln(r=1.74,P＞0.05).p.Lys1152Lys mutation was found in only 1 patient.Three SNPs( p.Arg872His,Ala1670Thr,Ser1691Pro) were always occurred in the same 83 RP patient and the relevance ratio was higher than controls ( P＜0.01 ).The age of night blindness on patients with concurrent three mutations was (30.54± 13.68 ) years,and the best corrected visual acuity (BCVA) was 0.50 ± 0.38.The age of night blindness on patients without concurrent three mutations was(21.06± 16.24) years,and the BCVA was 0.40 ±0.33 and were higher than controls ( t =2.11,P ＜ 0.05 ).Conclusions In this study,the prevalence of RP1 mutations among the RP patients in Ningxia population was lower than other populations (＜ 1％ ).The alliance of SNPs (p.Arg872His、p.Ala1670Thr、p.Ser1691Pro) may play a protective role on RP patients and reduce the frequency of mutatiaon in RP1 gene.