ObjectiveTo observe the disease-causing genes and the inheritance in sporadic retinitis pigmentosa (sRP) in Ningxia region. Methods49 sRP patients and 128 family members were recruited for this study. All the patients and family members received complete ophthalmic examinations including best corrected visual acuity, slit-lamp microscope, indirect ophthalmoscopy, fundus color photography, visual field, optic coherence tomography, full view electroretinogram. DNA was extracted from patients and family members. Using exon combined target region capture sequencing chip to screen the 230 candidate disease-causing gene mutations, polymerase chain reaction and direct sequencing were used to confirm the disease-causing mutations. Results24/49 patients (49.0%) had identified disease-causing genes, totally 16 genes were involved. There were 41 mutation sites were found, including 32 new mutations (78.0%). The disease-causing genes include USH2A, C2orf71, GNGA1, RPGR1, IFT140, TULP1, CLRN1, RPE65, ABCA4, GUCA1, EYS, CYP4V2, GPR98 and ATXN7. Based on pedigree analysis, 20 patients were autosomal recessive retinitis pigmentosa, 3 patients were autosomal dominant retinitis pigmentosa and 1 patient was X linked retinitis pigmentosa. 3/7 patients with USH2A mutations were identified as Usher syndrome. ConclusionsUSHZA is the main disease-causing of sRP patients in Ningxia region. 83.3% of sRP in this cohort are autosomal recessive retinitis pigmentosa.
Objective To observe the mutifocal electroretinogram (mfERG) characteristics of rod and cone cells in patients with retinitis pigmentosa (RP) and to evaluate the function of photosensory cell.Methods The mfERG recording technique for rod cell in eight normal subjects (eight eyes) were established and the influence of different brightness lightstimulus in P1 wave amplitude were analyzed. The cone and rod cells mfERG of 38 eyes in 19 patients were recorded and then calculated positive ratio from local signalnoise ratio. The average visual acuity and P1 wave amplitude density of cone mfERG in different types were compared and statistically analyzed. Meanwhile, the changes in P1 wave amplitude of cone and rod mfERG in four quadrants also compared and analyzed. Results Rod cell mfERG in normal subjects can be recorded stably by using blue flashes with low light intensity as 0.04 cd/m2. In patients with RP, the cone and rod cells mfERG can be detectd 65.79% and 10.51% respectively. P1 wave amplitude density in type I of cone cell mfERG was significantly higher than that in type II (t=5.21,P=0.000). There were no differences in average visual acuity (t=1.15, P=0.612). P1 wave amplitude density in type I was negatively related to logMAR visual acuity （r=-0.48，P=0.04）.The comparison of rod and cone cells mfERG in local wave characteristics showed that P1 wave amplitude densities had spatial relationship in each area. Conclusions The results suggested highly variable central responses in cone cell in RP patients, higher positive recorded ratio in cone cell than rod cell and spatial correspondence between the function of reserved cone and rod cells.
Objective To detect and analyse the mutations in rhodopsin gene of members in a family affected by autosomal dominant retinitis pigmentosa (ADRP). Methods Using the polymerase chain reaction (PCR), we amplified exon 1-5 of rhodopsin gene in patients with ADRP,and analyzed it with direct sequence measuement. Results The Gly-182-Asp mutation in the rhodopsin gene was detected in most of affected members of this ADRP family, but no mutation was detected in two affected members and the control ones. Conclusion We cannot regard the Gly-182-Asp mutation in the rhodopsin gene as the pathagenic factor of the ADRP family. It is likely there is a new gene next to the rhodopsin gene. (Chin J Ocul Fundus Dis, 2002, 18: 256-258)
Objective To detect characteristics and the pathogenesis of rhodopsin (RHO) gene mutation in an inbreeding family with autosomal recessive retinitis pigmentosa (ARRP). Methods Peripheral venous blood 5-8 ml was abstracted from 8 members in the inbreeding ARRP family and 10 control individuals. DNA gene group was picked. Extron 1-5 of RHO gene was amplified by polymerase chain reaction (PCR)，and the mutation of RHO gene was screened by direct DNA sequence measurement. Results The Gln-344-Arg mutation in the RHO gene was detected in 3 patients with ARRP and homozygotes of the mutation in 3 patients were found. Heterozygous of the mutation was detected in the parent of patients and 1 healthy family member. No mutation of RHO gene was found in 2 healthy family members and 10 control individuals. Conclusions The Gln-344-Arg mutation in the RHO gene may be the pathogenic factor of the ARRP family; the frequency of the mutation of RHO gene may increase in the in breeding ARRP family.(Chin J Ocul Fundus Dis，2004，20：145-148)
Retinitis pigmentosa (RP) is an inherited retinal disease characterized by degeneration of retinal pigment epithelial cells. Precision medicine is a new medical model that applies modern genetic technology, combining living environment, clinical data of patients, molecular imaging technology and bio-information technology to achieve accurate diagnosis and treatment, and establish personalized disease prevention and treatment model. At present, precise diagnosis of RP is mainly based on next-generation sequencing technology and preimplantation genetic diagnosis, while precise therapy is mainly reflected in gene therapy, stem cell transplantation and gene-stem cell therapy. Although the current research on precision medicine for RP has achieved remarkable results, there are still many problems in the application process that is needed close attention. For instance, the current gene therapy cannot completely treat dominant or advanced genetic diseases, the safety of gene editing technology has not been solved, the cells after stem cell transplantation cannot be effectively integrated with the host, gene sequencing has not been fully popularized, and the big data information platform is imperfect. It is believed that with the in-depth research of gene sequencing technology, regenerative medicine and the successful development of clinical trials, the precision medicine for RP will be gradually improved and is expected to be applied to improve the vision of patients with RP in the future.
Objective To observe the expression of cyclin dependent kinase 5 (Cdk5) and p25 in the pathogenesis of retinitis pigmentosa (RP) in Royal College of Surgeon (RCS) rats and its relationships with apoptosis. To explore the mechanism of Cdk5 and p25 induced photoreceptor apoptosis in the pathogenesis of RP. Methods Retinas of RCS and RCS-rdy+ rats were obtained at the ages of postnatal day 17, 25, 35, 60. The retinal structure and thickness of outer nuclear layer were measured by optical microscopy. The expression of Cdk5, p25, cleave-caspase 3 in the retina was evaluated by immunohistochemistry. The protein expression of cleave-caspase 3 in the retina was determined by Western blot. The apoptosis of retinal cells was examined by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The mean absorbance value of apoptotic cells was analyzed by SPSS 17.0 software. Results The retinal thickness of the RCS rats was significantly reduced in comparison to the RCS-rdy+ rats as the postnatal days progressed, particularly in the layer of rods and cones and the outer nuclear layer. The expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increased from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above indexes in RCS-rdy+ rats. The protein expression of cleave-caspase 3 in the RCS rats was significantly increased with progression of postnatal days to postnatal 35; but there was no obvious similar change in RCS-rdy+ rats. The results of TUNEL showed that the apoptotic cells significantly increased in the outer nuclear layer of RCS rats from postnatal 17 days to postnatal 35 days, while decreased on postnatal 60 days; but there was no obvious change of above index in RCS-rdy+ rats. This study showed that there were significant correlations between the following variables: Cdk5 expression and p25 expression, Cdk5 expression and cleave-caspase 3 expression, Cdk5 expression and apoptotic cells, p25 expression and cleave-caspase 3 expression, p25 expression and apoptotic cells, cleave-caspase 3 expression and apoptotic cells. The partial correlation coefficients were 0.949, 0.808, 0.959, 0.887, 0.979, 0.852, respectively and the P value was 0.000. Conclusions The apoptotic cells significantly increases and the expression level of Cdk5, p25, cleave-caspase 3 of RCS rats increases from postnatal 17 days to postnatal 35 days. The tendency of apoptotic cells to increase is consistent with the change of Cdk5, p25, cleave-caspase 3 expression. The apoptosis of photoreceptor cells is related to increasing expression of Cdk5 and p25 in RCS rats. Cdk5 may be involved in the development of RP in RCS rats.
ObjectiveTo observe and analyze the pathogenic genes and clinical phenotype characteristics of retinitis pigmentosa sinepigmento(RPSP). MethodsA retrospective clinical study. Two patients (proband) and five family members from two RPSP families admitted to Xiamen Eye Center of Xiamen University in December 2022 and Shenzhen Eye Hospital in July 2023 were included in the study. Two families have no blood relationship and were both Han Chinese. Detailed ocular and systemic medical history and specialized examinations were performed for all members, including color fundus photography, fundus autofluorescence (FAF), and full field electroretinogram (ff-ERG) examination. The peripheral venous blood of all members was collected, and genomic DNA was extracted. Pathogenic genes and their loci were screened using whole exome high-throughput sequencing technology. Sanger sequencing was used to verify the pathogenic genes in the two pedigrees. The pathogenicity of candidate variants was evaluated according to the American Society for American College of Medical Genetics and Genomics (ACMG) classification criteria and guidelines for genetic variants. ResultsThe two probands were male, aged 9 and 7 years, respectively. The main complaint was poor binocular vision for 6 and 3 years and poor treatment effect of amblyopia. The proband (Ⅱ2) in family 1 had a pale red color on the optic disc, with leopard-like changes in the posterior pole and thinner retinal arteries. FAF showed mottled fluorescence attenuation outside the macular vascular arch. There was no significant waveform in both bright and dark visual responses of ff-ERG. He also had 6-toed deformity of both feet, renal cysts, and a slightly overweight body. The clinical diagnosis was non-pigmentary retinitis pigmentosa. The proband of family 2 (Ⅱ1) had poor binocular vision in a dark environment and had atrophy lesions on the nasal side of the optic disc and leopard print like changes in the fundus. FAF showed uneven enhancement in the fovea. ff-ERG showed severe abnormalities in dark and light response, with significant decrease and delay in b-wave amplitude and latency. He had no other systemic abnormalities. The clinical diagnosis was binocular RPSP. There were no abnormal ocular and systemic manifestations in the two family members. Gene sequencing revealed a homozygous mutation (c.534+1G>T) of BBS2 gene, which was inherited from the mother and father respectively. Based on clinical manifestations and genetic testing results, the final diagnosis was Bardet Biedl syndrome. The genetic sequencing results confirmed a novel compound heterozygous mutation (c.950T>G: p. Leu317Arg missense mutation and c.849+1G>C splicing mutation) of BBS7 gene. His father (Ⅰ1) and mother (Ⅰ2) carried M1 heterozygous variants. Combined with the clinical manifestations and genetic testing results, the final diagnosis was Bardet-Biedl syndrome (BBS). Family 2 proband (Ⅱ1) carried the BBS7 gene C.950T>G (p.Leu317Arg) (M2) missense variation and C.849 +1G>C (M3) splice site variation. His father (Ⅰ1) and mother (Ⅰ2) carried M3 shear site variation and M2 missense variation, respectively. The two families all fit the autosomal recessive inheritance pattern, and the genotype and clinical phenotype were coseparated. According to ACMG guidelines, M1, M2 and M3 were all identified as possible pathogenic variants. ConclusionsBBS2 gene M1 homozygous variation and BBS7 gene M2, M3 complex heterozygous variation are the possible pathogenic genes in family 1 and family 2, respectively. Two families are affected by BBS and RPSP, respectively.
ObjectiveTo identify the causative gene in a family affected with Usher syndrome (USH) with retinitis pigmentosa sine pigmento (RPSP) and to analyze the genotype-phenotype correlation.MethodsA retrospective clinical study. A 9-year-old girl with RPSP type 1F USH diagnosed in the ophthalmology clinic of Henan Provincial People's Hospital in November 2019 and her parents were included in the study. The patient had bilateral night blindness for more than 4 years, she suffered from hearing loss 7 years, and is currently binaural sensorineural deafness. The best corrected visual acuity in both eyes was 0.5+. There was showed no obvious pigmentation on the fundus. The visual acuity of the peripheral field of vision decreased. Optical coherence tomography showed that the outer layer of the peripheral retina became thinner and the ellipsoid band disappeared. On electroretinogram examination, the rod and cone system response was severely decreased. The clinical phenotype of the parents of the child were normal. The peripheral venous blood of the child and his parents were extracted, the whole genome DNA was extracted, the custom developed targeted capture kit (PS400) was used, and the next-generation sequencing technology was used to detect genetic mutations. The suspected pathogenic mutation sites were verified by Sanger; co-segregation was performed among family members. The pathogenicity of variants were evaluated according to the interpretation standards and guidelines of sequence variants. Bioinformatics techniques were used to assess the impact of variants on encoded proteins.ResultsThe results of genetic testing showed that the proband detected the PCDH15 gene c.4109dupA (p.K1370fs) (M1), c.17dupA (p.Y6_L7delinsX) (M2) compound heterozygous mutation sites, verified by Sanger sequencing, the mutations were in the family in a state of co-segregation. According to the evaluation of sequence variation interpretation standards and guidelines, M1 and M2 were pathogenic variants of the PCDH15 gene. M1 led to a complete change in the transmembrane structure of the encoded protein, and M2 caused the gene to only translate 6 amino acids, which predicted that the PCDH15 protein cannot be synthesized. According to the clinical phenotype, gene mutation pathogenicity and protein structure prediction, the final clinical diagnosis was PCDH15-related type 1F.ConclusionsPCDH15 genes c.4109dupA and c.17dupA are the pathogenic mutation sites of USH in this family. These compound heterozygous new mutations lead to the failure of normal synthesis of PCDH15 protein, which leads to ocular and ear manifestations.
ObjectiveTo analyze the subfoveal choroidal thickness in retinitis pigmentosa (RP) patients and to evaluate the correlation between the subfoveal choroidal thickness (SCT) and visual function. MethodsTotally 42 RP patients (84 eyes) and 49 age and diopter-matched normal controls (98 eyes) were enrolled in this study. All the patients were taken the enhanced depth imaging technique of optical coherence tomography (EDI-OCT) examination for the measurement of the SCT. The covariate analysis was used to analyze the interaction effect between age and group. Then the SCT was amended. The RP patients were examined by 30°visual field test (T32 or LVC program) and electroretinogram (ERG) test. 32 eyes examined by T32 program, 52 eyes examined by LVC program. The waveform of ERG, mean sensitivity (MS) and mean defect (MD) were recorded. The relationship of SCT, MS and MD were analyzed by Pearson correlation analysis. ResultsThe SCT of RP patients and controls were (223.12±69.59), (288.29±52.36) μm. The covariate analysis of covariance with different age group interaction was not statistically significant (F=1.619, P=0.205), as amended SCT of RP patients and controls were (217.34±6.60), (293.20±6.00) μm, respectively. The SCT was decreased in RP patients (t=7.042, P < 0.001). Among 84 eyes, bright cone response weaken in 35 eyes, scotopic rod response weaken in 31 eyes. The difference of SCT in different ERG waveform was not significant (t=-0.976, -1.584; P=0.332, 0.117). The MS and MD of 32 eyes using T32 program were (9.05±6.42), (18.84±6.30) dB, the SCT was (209.83±71.48) μm; the MS and SCT of 52 eyes using LVC program were (7.14±5.03) dB and (228.32±66.32) μm. The SCT was related to MS (r=0.494, P=0.003) and MD (r=-0.448, P=0.009) in eyes using T32 program. There was no correlation between SCT and MD in eyes using LVC program (r=-0.232, P=0.095). ConclusionsThe SCT of RP patients is thinner than that of normal controls. The SCT of RP patients is related to MS and MD of T32 program, but not correlated to ERG waveform and MS of LVC program.
Objective To observe the characteristics of fundus autofluorescence (AF) in short wavelength AF (SW-AF) and Near Infrared AF (NIR-AF), and their relationship with visual fields. Methods Twelve patients (24 eyes) with primary RP were enrolled in this study. The patients included nine males (18 eyes) and three females (six eyes). The patients aged from 15 to 69 years, with a mean age of (35.33plusmn;15.03) years. All the patients were examined for color photography, SW-AF, NIR-AF, visual fields and optical coherence tomography examination. Results There were hyper-AF ring of varying sizes in posterior pole by SW-AF and NIR-AF examinations. The area of hypo-AF which located in SW-AF hyper-AF ring had a positive correlation with the area of hyper-AF in the NIR-AF (r=0.662，P＜0.05). OCT showed that outside the hyper-AF ring, there were disconnected inner segment/outer segment (IS/OS) junction and external limiting membrane, and thinned outer nuclear layer and retinal pigment epithelium. Peripheral retinal osteocytes-like pigmentation showed non fluorescence in SW-AF and NIR-AF. The plaque-like area showed mottled and low fluorescence examined by SW-AF. SW-AF hyper-AF ring had a positive correlation with visual fields (r=0.492，P＜0.05). Conclusions The area of hypo-AF inside of the SW-AF hyper-AF ring is related to visual fields in RP patients. The retinal structures in the hypo-AF area inside of the SW-AF hyper-AF ring, and in the NIR-AF hyper-AF region are normal.