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This study aims to explore the effect of Lycii Fructus and Salviae Miltiorrhizae Radix et Rhizoma(LFSMR), a drug pair possesses the function of nourishing Yin, promoting blood circulation, and brightening the eyes, in treating retinitis pigmentosa(RP)by inhibiting the gliosis of Müller cells(MCs) and inducing their reprogramming and differentiation into various types of retinal nerve cells. Twelve C57 mice were used as the normal control group, and 48 transgenic RP(rd10) mice were randomly divided into the model group, positive control group, and low and high dose LFSMR groups, with 12 mice in each group. HE staining was used to detect pathological changes in the retina, and an electroretinogram was used to detect retinal function. Retinal optical coherence tomography was used to detect retinal thickness and perform fundus photography, and laser speckle perfusion imaging was used to detect local retinal blood flow. Digital PCR was used to detect gene expression related to retinal nerve cells, and immunofluorescence was used to detect protein expression related to retinal nerve cells. LFSMR could significantly improve the pathological changes, increase the amplitude of a and b waves, increase the retinal thickness, restore retinal damage, and increase retinal blood flow in mice with RP lesions. LFSMR could also significantly inhibit the m RNA expression of the glial fibrillary acidic protein( GFAP) during the pathogenesis of RP and upregulate m RNA expression of sex determining region Y box protein 2(SOX2), paired box protein 6(Pax6),rhodopsin, protein kinase C-α(PKCα), syntaxin, and thymic cell antigen 1. 1(Thy1. 1). LFSMR could significantly inhibit GFAP protein expression and enhance protein expression of SOX2, Pax6, rhodopsin, PKCα, syntaxin, and Thy1. 1. It could also reverse the pathological changes in the retina of rd10 mice, improve retinal function and fundus performance, increase retinal thickness, enhance local retinal blood flow, and exert therapeutic effects on RP. The mechanism of action of LFSMR may be related to inhibiting the gliosis of MCs and promoting their reprogramming and differentiation into various types of retinal nerve cells.

Objective: To explore the genetic basis for a patient with autosomal dominant retinitis pigmentosa (RP)., Methods: A male patient with RP treated at Gansu Provincial Maternal and Child Health Care Hospital in September 2019 was selected as the study subject. Clinical data was collected. Peripheral blood samples of the patient and his parents were subjected to whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing and bioinformatic analysis., Results: The patient, a 29-year-old male, developed night blindness, amblyopia, visual field defects and optic disc abnormalities since childhood. Gene sequencing revealed that he has harbored a heterozygous c.942G>C (p.Lys314Asn) variant of the IMPDH1 gene, which was inherited from his mother, whilst his father was of the wild type. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.942G>C variant was predicted as likely pathogenic (PM1+PM2_Supporting+PP3+PP1)., Conclusion: The c.942G>C (p.Lys314Asn) variant in the IMPDH1 gene probably underlay the RP in this patient.

Biallelic pathogenic variants in the USH2A gene result in Usher syndrome type Ⅱ and non-syndromic retinitis pigmentosa, both of which entail the progressive loss of photoreceptors leading to blindness. The cDNA of the USH2A gene is extensive, consisting of 15 606 base pairs, rendering it impractical for delivery via adeno-associated virus vectors for gene replacement therapy. Notably, exon 13 has emerged as a focal point for therapeutic intervention, given its predilection for harboring the most pathogenic variants within USH2A. Recent intervention studies targeting USH2A exon 13 through the utilization of antisense oligonucleotides, genome editing, and RNA editing approaches have exhibited promising therapeutic potential. This paper provides a comprehensive overview of the molecular mechanisms, outcome data, and the challenges associated with the application of these interventions in this domain.

Objective: To explore the genetic basis for a patient with early-onset retinitis pigmentosa (RP)., Methods: A patient who had presented at the West China Hospital of Sichuan University on March 10, 2020 was selected as the study subject. The patient and his parents were subjected to whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing and in silico analysis., Results: The patient has featured substantial loss of binocular vision field. Funduscopy revealed characteristic bone spicule-type pigment deposits, as well as attenuated retinal arterioles and pale-appearing optic discs. WES revealed that he has harbored compound missense variants of a RP-associated CRB1 gene, including c.2969T>C (p.Leu990Ser) and c.1816T>C (p.Cys606Arg), which were respectively inherited from his father and mother. Homozygous c.1816T>C (p.Cys606Arg) variant has been identified among RP patients, whilst the c.2969T>C (p.Leu990Ser) variant was unreported previously. Both variants were predicted as likely pathogenic based on the guidelines from the American College of Medical Genetics and Genomics (ACMG)., Conclusion: The novel compound heterozygous variants of the CRB1 gene probably underlay the early-onset RP in this patient. Above finding has enriched the mutational spectrum of the CRB1 gene.

Oliver-McFarlane syndrome is a rare genetic disorder characterized by long eyelashes, choroidoretinal atrophy, and multiple pituitary hormone deficiencies. The patient in this case is a 29-year-old female who has suffered from night blindness, low vision, and long eyelashes since childhood. Through genetic sequencing, she was diagnosed with compound heterozygous variaton in the PNPLA6 gene, indicating Oliver-McFarlane syndrome based on her comprehensive clinical presentation.

Objective: To explore the genetic basis for a Chinese patient with retinitis pigmentosa (RP)., Methods: Whole exome sequencing (WES) was carried out to screen potential variant in the proband. Candidate variants were determined by taking consideration of clinical phenotype. Sanger sequencing was used to verify the variant in the proband and his parents., Results: The proband was found to harbor compound heterozygous variants of c.8G>A (p.Cys3Tyr) and c.958_959insA (p.Arg320Glnfs*29) in the C2ORF71 gene, which has derived from his father and mother, respectively. Both variants were unreported previously. Based on the ACMG guidelines, they were predicted to be likely pathogenic and pathogenic, respectively., Conclusion: The novel compound heterozygous variants of the C2ORF71 gene probably underlay the pathogenesis of RP in the proband. Above finding has enriched the spectrum of C2ORF71 gene mutations and facilitated genetic counseling for the family.

Objective: To identify the pathogenic mutation underlying retinitis pigmentosa in a large pedigree., Methods: The pedigree has included three generations showing an autosomal dominant transmission of retinitis pigmentosa. Potential mutations were screened using a retinitis pigmentosa gene panel and an Ion PGM platform. Suspected mutation was verified by Sanger sequencing., Results: A novel heterozygous missense mutation, c.251T>C(p.Leu84Pro), was identified in the RHO gene. The mutation has co-segregated with the retinitis pigmentosa phenotype among all family members and was not found in public databases ExAC, 1000G and dbSNP or 831 healthy controls. The mutation was predicted to be damaging by three major protein-predicting software., Conclusion: The c.251T>C (p.Leu84Pro) mutation of the RHO gene is a novel pathogenic mutation underlying the retinitis pigmentosa phenotype in this pedigree. Above findings have enabled prenatal diagnosis for the pedigree.

Objective: To explore the genetic etiology of a pedigree affected with hereditary retinitis pigmentosa., Methods: High-throughput DNA sequencing was used to analyze the sequences of 173 genes associated with hereditary eye diseases in the proband. Suspected mutation was verified with PCR amplification and Sanger sequencing., Results: The proband was found to have carried a c.570_571 ins GAAGATGCTGT insertional mutation in the RP2 gene located on the X chromosome. All female carriers of the pedigree were heterozygous, while all affected males were hemizygous for the same mutation., Conclusion: The inheritance pattern of this retinitis pigmentosa pedigree was X-linked recessive. The c.570_571 ins GAAGATGCTGT insertional mutation of the RP2 gene probably underlies the disease.

Retinitis pigmentosa (RP) is a group of inherited disorders which involve photoreceptors of the retina and can lead to visual loss. The genetic and clinical phenotypes of RP feature high heterogeneity. RP can be divided into nonsyndromic and syndromic types, both may feature autosomal dominant, autosomal reccesive and X-linked inheritance. So far, many genes have been identified, most of which are expressed in the photoreceptors or retinal pigment epithelium. Sixty-three genes have been identified in nonsyndromic RP. This paper reviews recent progress in the research of the genetics of RP.

Objective: To detect the disease-causing genes of 10 retinitis pigmentosa pedigrees by using exon combined target region capture sequencing chip., Methods: Pedigree investigation study. From October 2010 to December 2013, 10 RP pedigrees were recruited for this study in Ningxia Eye Hospital. All the patients and family members received complete ophthalmic examinations. DNA was abstracted from patients, family members and controls. Using exon combined target region capture sequencing chip to screen the candidate disease-causing mutations. Polymerase chain reaction (PCR) and direct sequencing were used to confirm the disease-causing mutations., Results: Seventy patients and 23 normal family members were recruited from 10 pedigrees. Among 10 RP pedigrees, 1 was autosomal dominant pedigrees and 9 were autosomal recessive pedigrees. 7 mutations related to 5 genes of 5 pedigrees were detected. A frameshift mutation on BBS7 gene was detected in No.2 pedigree, the patients of this pedigree combined with central obesity, polydactyly and mental handicap. No.2 pedigree was diagnosed as Bardet-Biedl syndrome finally. A missense mutation was detected in No.7 and No.10 pedigrees respectively. Because the patients suffered deafness meanwhile, the final diagnosis was Usher syndrome. A missense mutation on C3 gene related to age-related macular degeneration was also detected in No. 7 pedigrees. A nonsense mutation and a missense mutation on CRB1 gene were detected in No. 1 pedigree and a splicesite mutation on PROM1 gene was detected in No. 5 pedigree., Conclusions: Retinitis pigmentosa is a kind of genetic eye disease with diversity clinical phenotypes. Rapid and effective genetic diagnosis technology combined with clinical characteristics analysis is helpful to improve the level of clinical diagnosis of RP.

Objective: To identify the pathogenic mutation in a four-generation Chinese family with autosomal dominant retinitis pigmentosa (ADRP) and to analyze its associated clinical phenotypes., Methods: Twelve participants from the index family were recruited, including 5 patients, 6 asymptomatic siblings, and one spouse. All participants underwent ophthalmic examinations, including best-corrected visual acuity (BCVA), visual field (VF) testing, fundus photography, and full-field flash electroretinography (ERG). Targeted sequence capture array technique with next-generation of high throughput sequencing(NGS) was performed to detect variants in 189 hereditary retinal disease (HRD) related genes, comprising 179 identified HRD-causing genes and 10 potential causative genes which were involved in pre-messenger RNA(pre-mRNA) splicing. Variants detected by targeted sequencing were filtered by bioinformatic analyses, validated by Sanger sequencing and intra-familiar analysis.Genotype-phenotype correlation was also analyzed., Results: SNRNP200 p.S1087L was identified as the disease causative mutation for this family by targeted sequencing and optimized bioinformatic analyses. This family demonstrated early onset of the disease by presenting nyctalopia among 6 to 8 years old, performed rapid disease progression and severely impaired visual function by displaying loss of VF among 14 to 17 years old and decreased central vision among 21 to 28 years old. The fundus presentations and ERG results showed typical RP presentations., Conclusions: SNRNP200 p.S1087L is identified as a hotspot mutation but correlates with distinct phenotypes in the present family, including early onset of the disease, rapid disease progression, and severely impaired visual function. This study also give evidence to that molecular diagnostic platform for HRD can improve the detection rate of causative genes/mutations in HRD patients, thus providing important approaches for further investigation of the genetic causes for HRD.

Objective: To analyse the mode of inheritance and clinical characteristics of retinitis pigmentosa (RP) patients with consanguineous marriage., Methods: RP patients were recruited for this study in Ningxia Eye Hospital from September 2009 to July 2011. All patients received complete ophthalmic examination. The mode of inheritance were determined based on family history and marriage history. Clinical features were characterized by complete ophthalmic examinations including visual acuity, macular OCT, visual field and electroretinogram (ERG)., Results: A total of 143 individuals with RP (33 families) were recruited. Based on analysis of family history and marriage history, 20 RP families (23 patients) had consanguineous marriage history accounted for 60.6% RP families (16.1% RP patients). There were 4 patients (from 4 families) diagnosed as Usher syndrome. In 20 RP families with consanguineous marriage history, 7 families (35.0%) were Hui ethnicity and 13 families (65%) were Han ethnicity. The marriages of 15 families were between first cousins and 3 families were between second cousins, only 2 families were between half cousins matrimony. Of 23 RP patients, 12 were males and 11 were females. The average age of onset was 11.4 ± 6.8 years and the average age of recruitment was (32.0 ± 13.5) years. The best-corrected visual acuity was less than 0.6 in 78.2% patients. According to the features of the fundus, 13 patients were classical retinitis pigmentosa and 10 patients were retinitis pigmentosa sine pigmento. Visual field examination showed that all patients had varying degrees of peripheral visual field defect. Retinal neuroepithelial layer of macular and peripheral retina became thinner and retinal photoreceptors were disappeared. The average thickness of macular fovea was (186.1 ± 78.7) µm on right eyes and (187.4 ± 76.3) µm on left eyes., Conclusions: The incidence of RP with consanguineous marriages was high in Ningxia Region. The mode of inheritance of RP patients with consanguinity is autosomal recessive. The common marriage pattern of consanguinity is between first cousins. The age of onset is early and the ocular fundus changes of some patients are atypical, this should be paid attention clinically.

Objective: To map the gene responsible for a three generations family with autosomal dominant retinitis pigmentosa (ADRP) and screen the mutation in candidate genes., Methods: For a 14-member family with 7 suspected patients, systematic and ophthalmic examinations were performed including visual acuity, ophthalmoscopy, perimetry and electrophysiologic test. After the genomic DNA was extracted, genome scanning was performed, and candidate genes were screened for potential mutations., Results: The maximal two-point LOD score was obtained at D1S252 with a value of 2.02 (θ=0.00), and multi-point LOD score reached its maximum 2.28 at D1S252. However, no mutations were detected in two candidate genes in this region, namely PRPF3 and SEMA4A by direct sequencing., Conclusion: Significant evidence for linkage was found at the chromosome region of 1p21.1-q23.3. However, neither PRPF3 nor SEMA4A has harbored a mutation. There may exist an additional gene which is responsible for this disease.

Objective: To screen the mutation in the RPGR gene in a large Chinese family with X-linked recessive retinitis pigmentosa (RP) and to describe the phenotype in affected males and female carriers., Methods: Ophthalmic examinations were performed in 77 family members of a RP pedigree to identify affected individuals. Polymerase chain reaction (PCR) and direct sequencing were used for screening of mutations in RPGR gene exon ORF15., Results: Mutation screening demonstrated a novel mutation, g.ORF15 + 577_578delAG, which caused an open reading frameshift and resulted in premature truncation of the RPGR protein. This mutation was detected in 8 affected male individuals and 14 obligate female carriers in this family and was found to segregate with the phenotype in this family. This mutation led to a severe RP phenotype in male affected individuals with some variability in the age of onset of night blindness and loss of visual acuity, but was recessive in female carriers without a RP phenotype. However the most striking phenotypic feature in female carriers in this pedigree was moderate to high myopia with refractive error ranging from -5.00 D to -22.00 D in 14 female carriers., Conclusions: This novel mutation in RPGR ORF15 causes serious RP phenotype in males and no RP phenotype in female carriers. Moderate to high myopia was a particular feature for female carriers in this pedigree. Our finding expands the spectrum of RPGR mutations causing RP and phenotypic spectrum of the disease in Chinese family, which is useful for further genetic consultation and genetic diagnosis.

Objective: To map the disease-causing gene in a Chinese family with autosomal dominant retinitis pigmentosa., Methods: Twenty-seven micro-satellite markers were randomly selected from the region around the known loci of causative genes, and haplotypes were determined by ABI3100 genetic analyzer. Two-point linkage analysis was performed using MLINK., Results: The Lod score of each marker vs adRP was below 1., Conclusion: The phenotype of this family may not be caused by mutation of the known disease-causing genes.

Objective: To illuminate pathogenic gene and mutation in a Chinese family with autosomal dominant retinitis pigmentosa (adRP)., Methods: Genetic linkage analysis was performed on the known genetic loci for adRP with a panel of polymorphic markers, and then all exons including exon-intron boundary, 5oUTR and 3oUTR of the candidate gene were sequenced directly., Results: Two-point LOD scores were negative with all markers tested except D17S701 (Zmax=2.107, theta=0) and D17S1604 (Zmax=1.806, theta=0). The disease gene locus was confined to RP17 with further genetic linkage and haplotype analysis. Screening all exons including exon-intron boundary, 5oUTR and 3oUTR of carbonic anhydrase 4 (CA4) revealed no mutation in this family., Conclusion: The disease-causing gene of one Chinese family with adRP was first mapped to RP17, however no gene mutation of CA4 was detected in this family. Maybe there is a complex CA4 gene mutation in this family or a new disease-causing gene for this family in this locus, further study need to be done.

Objective: To evaluate the disease-causing gene and phenotypic characters of a large family with autosomal dominant retinitis pigmentosa (adRP)., Methods: Disease status and associated ocular abnormalities of eight patients and six unaffected members who represent different generations of this family were assessed by measurement of visual psychophysics, full-field and multifocal electrophysiology (ERG and mfERG) and funds fluorescent angiography (FFA). The DNA samples of nineteen patients and fifteen unaffected individuals in this family were examined by Genome scanning, linkage analysis and mutation detection to identify coding sequence changes., Results: A case with variable, early onset night blindness before 10 years and visual field loss in their teens was found. Macular dystrophy, progressing to a retinitis pigmentosa phenotype was demonstrated in most adult cases. Both a-wave and b-wave amplitudes of photopic and scotopic full-field ERG were marked reduced and nearly non-detectable, demonstrating severe damage of photoreceptor systems. There were two obligate gene carriers in the family which remained asymptomatic in the clinical. But one of them was found with a minimal RP characteristic and the other was normal by examination of fundus and ERG. An unreported splicing site mutation (IVS5-1G > A) was identified in intron 5- acceptor site of PRPF-31 gene on chromosome 19. ERG and molecular genetic findings were consistent with the reclassification of this disease as an autosomal dominant RP., Conclusion: It is a novel splicing site mutation that IVS5-1G > A of D19S418 site in PRFP31, the relative phenotypes by which main displayed type I/diffuse has variable expressivity and complex phenotype.

Objective: To identify the mutation patterns of RHO and RP1 genes in the Chinese patients with retinitis pigmentosa (RP) and to explore their potential interactions in the pathogenesis of RP., Methods: Sequence alterations in the entire coding region and splice sites of RHO and RP1 gene were screened in 151 RP affected probands and 150 unrelated controls who were all Hong Kong Chinese. Additional 46 relatives of 12 RP probands carrying possible mutations in RHO or RP1 were recruited for segregation analysis. Univariate analysis, multivariate analysis and genotype-pedigree disequilibrium test were used to examine the associations of polymorphisms in these two genes with RP., Results: Two mutations in the RHO gene, 5211delC and P347L, were identified each in one proband from the 151 probands, accounting for 1.3% of the RP patients. Two mutations in the RP1 gene, R677X and D984G, were identified each in one proband from the 151 probands, also accounting for 1.3% of the RP patients. In univariate analysis, non-coding sequence variants in the RHO gene, -26G > A, was found to increase the risk of RP, while R872H in the RP1 gene was likely to be a protective factor for RP. Multivariable logistic regression analysis and haplotype analysis confirmed these associations., Conclusion: The prevalences of RHO and RP1 mutations among the RP patients in Chinese population are both less than reported in other populations. Besides the disease-causing mutations, non-coding sequence alterations may also be a modifier for RP. The potential interactions between RHO and RP1 suggest a digenic etiology for RP.

Objective: To detect mutation in the rhodopsin gene (RHO) in a Chinese family with autosomal dominant retinitis pigmentosa (ADRP)., Methods: A total of 25 family members from a Chinese family were investigated. All the subjects were examined clinically by direct funduscopy, perimetry and vision test. Evaluation of the proband included electroretinography (ERG). Genomic DNA was extracted using standard method. The complete coding regions of RHO were amplified by polymerase chain reaction (PCR) and the PCR products were subjected to automatic DNA sequencing., Results: 512 C>T (P171L), a recurrent missense mutation was detected in the proband. All 12 affected subjects in the family were heterozygous for the mutation. The affected individuals had night blindness at the age of 5-6 years. They had relatively severe impairment of visual acuity and suffered a gradual loss of peripheral visual field at the age of 20-30 years. And they went blind at the age of 40-50 years. Rod and cone ERG were not detectable in the proband., Conclusion: A recurrent missense mutation, 512C>T (P171L), was detected in a Chinese family with ADRP.

Objective: To identify mutations in a four-generation Chinese family with retinitis pigmentosa and to investigate its clinical phenotype., Methods: Ophthalmic and electrophysiological examinations of patients with RP were performed. A genome-wide scan and linkage analysis were conducted in this family. Direct genomic sequencing was used to evaluate the candidate gene. A restriction assay was used to confirm the mutation status in this family, and to exclude it as a polymorphism in a reference population., Results: The mutation gene was mapped close to RP11 in chromosomal region 19q13.4 by linkage analysis. A novel single heterozygous base substitution (G > C) was detected at the beginning of intron 8 in the PRPF31 gene whereby the consensus GT dinucleotide of the intron 8 splice donor site was changed to CT. The mutation was co-segregated completely with the disease phenotype, but was absent in the unaffected relatives and in 100 reference subjects, thus supporting its pathogenic nature in this family. The clinical findings of RP patients were consistent with a relatively severe and diffuse type of RP., Conclusion: A novel splice site mutation (IVS8 + 1G > C) in the PRPF31 gene caused retinitis pigmentosa in the four-generation Chinese RP family studied.

Retinitis pigmentosa (RP) is a common genetic eye disease affecting about 1 in 3500 people worldwide with pan-ethnic occurrence. So far there is no effective treatment for RP. This paper gives an overview on recent advances in molecular genetics of RP with emphasis on the important gene mutations for diagnosis and prognosis, and a review on gene therapy of RP.

Objective: To investigate the mutation spectrum of phosphodiesterase beta subunit (PDE6B) gene and incidence in Chinese retinitis pigmentosa (RP) patients., Methods: Genomic DNA was extracted from the blood samples of 38 patients from 35 autosomal recessive retinitis pigmentosa (ARRP) families and 55 sporadic cases. The mutation of the PDE6B gene was detected using PCR-SSCP, and the amplified PCR product of abnormal bands was sequenced., Results: Within intron 10 of PDE6B gene, a mutation was found in an ARRP family, a G --> A transition at 19th base upstream 5'-end of exon 11. A novel complex heterozygous variant of PDE6B gene in a sporadic case, a T to C transition in codon 323 resulting in the substitution of Gly by Ser and two bp(TG) inserted between the 27th-28th bp upstream of the 5'-end of exon 10 were both present in the same isolate RP. But they were not found in 100 unrelated normal individuals. A sporadic RP was found carrying a sequence variant of PDE6B gene, a G to C transversion in intron 18, the 15th base adjacent to the 3'end of exon 18. Another isolate RP was found to have 2 bp inserted between 31st and 32nd base upstream 5'end of exon 4 (in intron 3) of PDE6B gene., Conclusion: There is a complex heterozygous mutation of PDE6B gene responsible for a sporadic RP patient in China. Several DNA variants were found in intron of PDE6B gene in the national population.

Objective: To study the relationship between the rhodopsin gene on chromosome 3 and autosomal dominant retinitis pigmentosa (ADRP) in a Chinese kindred., Methods: Sixteen normal persons and 18 RP patients in a ADRP family were recruited. Genome scan method based on fluorescence labeled (using 3 different labels: 6-FAM, HEX, and NED) microsatellite markers with multiplex PCR system was used to identify loci influencing susceptibility to ADRP. Fourteen microsatellites (D3S1297, D3S1263, D3S1266, D3S1289, D3S1300, D3S3681, D3S1271, D3S1292, D3S1569, D3S1279, D3S1614, D3S1262, D3S1580 and D3S1311) on chromosome 3 were used as genetic markers. Linkage analysis (using Genescan3.0, GeneScan Analysis 2.1, Genotyper 2.1 and Designer sofe system) was performed using these markers., Results: The LOD value was

Objective: To determine the causative mutation in a 5 generation pedigree with autosomal dominant retinitis pigmentosa (ADRP)., Methods: Genomic DNA from four patients and 4 normal persons in the same pedigree suffering ADRP were extracted, and subsequently eight exons of three ADRP candidate genes were screened for mutations by a combined polymerase chain reaction-single strand conformation polymorphism and DNA sequencing techniques., Results: A new point mutation in rhodopsin gene at codon 52 of exon 1 (TTC to TAC) that resulted in a substitution of Tyr to Phe was detected in the four affected family members, but not in the four control individuals from the same pedigree., Conclusion: A causative mutation of rhodopsin gene was identified in a large Chinese pedigree with ADRP. The present study confirmed the molecular genetic heterogeneity of ADRP.

Objective: To identify the mutation spectrum of phosphodiesterase beta subunit (PDE6B) gene, the incidence in Chinese patients with retinitis pigmentosa (RP) and their clinical phenotypic characteristics., Methods: Screening of mutations within PDE6B gene was performed using polymerase chain reaction-heteroduplex-single strand conformation polymorphism (PCR-SSCP) and DNA sequence in 35 autosomal recessive (AR) RP and 55 sporadic RP cases. The phenotypes of the patients with the gene mutation were examined and analyzed., Results: Novel complex heterozygous variants of PDE6B gene in a sporadic case, a T to C transversion in codon 323 resulting in the substitution of Gly by Ser and 2 base pairs (bp: G and T) insert between the 27th-28th bp upstream of the 5'-end of exon 10 were both present in a same isolate RP. But they are not found in 100 unrelated healthy individuals. Ocular findings showed diffuse pigmentary retinal degeneration in the midperipheral and peripheral fundi, optic atrophy and vessel attenuation. Multi-focal ERG indicated that the rod function was more severely deteriorated. A mutation was found in a case with RP in a ARRP family, a G to A transversion at 19th base upstream 5'-end of exon 11 (within intron 10) of PDE6B gene. A sporadic RP carried a sequence variant of PDE6B gene, a G to C transition, at the 15th base adjacent to the 3'-end of exon l8. In another isolate case with RP was found 2 bp (GT) insert between 31st and 32nd base upstream 5'-end of exon 4 (in intron 3) of PDE6B gene., Conclusions: There are novel complex heterozygous mutations of PDE6B gene responsible for a sporadic RP patient in China. This gene mutation associated with rod deterioration and RP. Several DNA variants were found in introns of PDE6B gene in national population.

Objective: To test the frequency and pattern of rhodopsin (RHO) mutations in Chinese retinitis pigmentosa (RP) patients and to evaluate their effects in the pathogenesis of RP., Methods: Genomic DNA was extracted from peripheral blood samples of 100 Hong Kong Chinese RP patients. Sequence variants of the entire coding exons of the RHO gene were tested using PCR, conformation sensitive gel electrophoresis and DNA sequencing., Results: Totally six nucleotide changes were identified, among which three were silent mutations, two missense mutations and one deletion mutation. P347L was found in one RP proband and her three children who also had RP. P327(1 bp del) was novel and detected in a late-onset RP patient of 53 years. Her 26-year-old daughter, also carrying the identified mutation, had no RP phenotypes except for the mottled retinal pigment epithelium (RPE) revealed by fundal examination. Neither of the two mutations was detected in normal controls., Conclusion: Two patients had disease-causing mutations in the RHO gene, thus RHO mutations cause about 2.0% (95% confidence interval: 0.2%-7.0%) of all RP among Chinese in Hong Kong. A highly conserved C-terminal sequence QVS(A)PA was altered due to P347L and thereby resulting in an aberrant subcellular localization of rhodopsin. Loss of all six phosphorylatable residues at the C-terminus and the highly conserved C-terminal sequence QVS(A)PA may occur because of P327(1 bp del). To elucidate the predominant biochemical defects in such mutant, transgenic mice and transfected culture cells carrying P327(1 bp del) would be of greatest value.

Objective: To report the localization of a gene for an autosomal dominant retinitis pigmentosa (ADRP) family., Methods: We studied a large ADRP family, collected 3 - 5 ml of venous blood samples from some family members, and genomic DNA was extracted from the blood. Then two-point linkage analysis between the known markers and the disease locus was performed., Results: Linkage analysis showed the maximum LOD score reaches 2.732852 at marker D3S1292 (at recombination fraction theta = 0.1)., Conclusion: Since D3S1292 was localized at 3q21, we roughly localized the disease gene on 3q21. In the mean time, the rhodopsin gene had been reported as linked to 3q21 adjacent to D3S1292, thus we think the disease gene may be the rhodopsin gene.

Objective: To investigate the frequency and pattern of RP1 point mutations in Chinese retinitis pigmentosa (RP) patients and to examine their effects on the development of RP., Methods: Conformation sensitive gel electrophoresis (CSGE) and direct DNA sequencing were used to determine sequence alterations occurring in the entire coding region of the RP1 gene in 101 Chinese RP patients in Hong Kong., Results: R677X was detected in one RP patient. A nonpathogenic nonsense mutation, R1933X, was identified in three normal individuals and one patient with Stargardt disease. The frequency of RP1 mutations among all RP patients in this study is 1/101. R677X is expected to lead to large disruptions of the encoded protein. Additionally, 10 more missense alterations in the RP1 gene were identified in the subjects of this study. Apart from M479I whose pathogenicity can not be determined currently, other sequence changes are just polymorphisms of the RP1 gene., Conclusion: The nonpathogenicity of R1933X indicates that the C-terminal 224 residues of RP1 protein may be not critical for RP1. Recently, a C-termnal truncating mutation, Y1053(1 bp del), was reported to occur in an RP patient. Thus RP can be caused by lack of the region of RP1 protein after codon 1052 but before 1933. To confirm such a proposition, a large genotyping study is necessary and is likely to reveal more RP causative mutations and uncover more sequence alterations different from those of other ethnic groups.

Objective: To detect rhodopsin (RHO) mutation in Chinese families with autosomal dominant retinitis pigmentosa (ADRP) and study on the association of RHO gene mutations with clinical phenotype., Methods: Twenty-seven members from 13 Chinese families with ADRP and 30 normal subjects were recruited. The complete coding regions of the rhodopsin gene were amplified with polymerase chain reaction (PCR) and then DNA single-strand conformation polymorphism (SSCP) technique was used to screen RHO gene mutations. When a variant band was observed after the SSCP electrophoresis, the variant band was analyzed by sequencing PCR-amplified DNA. All subjects were examined clinically by slit-lamp, direct funduscopy, Goldmann kinetic perimetry, Humphrey threshold perimetry and electroretinogram., Results: Nine affected subjects and 2 boys (11 and 9 years old respectively) in one pedigree among 13 families were found to have three DNA single strand bands by SSCP analysis. Results of assaying sequence showed the 11 members were heterozygous for rhodopsin E341ter mutation. The codon 341 is changed from GAG to TAG, resulting in a stop codon mutation. Thirty normal controls and unaffected subjects in this family were the wild type of RHO gene. Affected individuals reported night blindness in the second decade, showed optic atrophy, vessel attenuation and a few bone spicule-like pigments in the peripheral retina. The impairment of visual acuity was relatively severe, loss of peripheral visual field was greatly considerable after 30 years of age, rod and cone ERG were not detectable in the second decade, and only slight cone response was left., Conclusions: The natural history of RP in this family begins with a loss of rod function, progresses to involve the cone system, and leads eventually to a severe loss of visual function. A novel rhodopsin gene mutation E341ter is responsible for a Chinese family with ADRP.

Objective: To clone the differentially expressed genes in the retina of rds mouse (the animal model of congenital retinitis pigmentosa) during the disease development., Methods: The retinal mRNA of rds mouse during the development of retinitis pigmentosa was analyzed by the mRNA differential display. The differentially expressed mRNA fragments were cloned and sequenced., Results: There was obvious difference of gene expression between rds mouse and the control during the development of retinitis pigmentosa. Five differentially expressed bands were cloned and sequenced. One of those had 86% identity (132/154) with the sequence of the human cDNA DKFZp434D1227 from adult testis in GenBank, which was submitted lately (15-Oct-1999) and without much information. The other had lower identity with the sequences in GenBank. A highly expressed clone in the rds mouse on postnatal day 25 had the same length as another clone in the normal on postnatal day 37, which was not expressed in the rds mouse on day 37. The sequences of the two clones were identical in all but two base pairs., Conclusion: These results indicate that there are a lot of novel differentially expressed genes in the chronic processing diseases, such as retinitis pigmentosa.

Objective: To detect mutations of the RP2 gene in two Chinese families with X-linked retinitis pigmentosa (XLRP)., Methods: Eight pairs of primers designed from exon and intron sequence of the RP2 gene were used for the amplification of eight segments which encompass all exons of the gene. PCR were carried out with human genomic DNA as the template. The PCR products were sequenced after being purified. Mutation was identified by comparing DNA sequences of patients with that of normal controls., Results: The mutation 358C-->T was detected in exon 2 of the RP2 gene in both families. It changed the codon CGA for Arginine to a terminator codon TGA and causes retinitis pigmentosa in the two families., Conclusion: The mutation 358C-->T is useful in analyzing the function of RP2 protein and gene diagnosis of XLRP.

Objective: To investigate retinal degeneration slow (RDS) gene mutation in a Chinese family with primary retinitis pigmentosa (RP) and the association of the mutation with clinical phenotypes and to explore the pathogenesis of RP., Methods: Blood DNA from 2 patients in the same family with RP and 2 normal persons was analyzed by molecular genetic methods. RDS gene mutation was screened out by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. The mutant RDS gene fragment was cloned, then sequenced with an automatic DNA sequencer using a dideoxy chain termination protocol. The phenotype of the patients with the gene mutation were examined and determined by clinical ophthalmologic examinations., Results: The PCR-RFLP analysis of the RDS gene in 2 patients with RP revealed codon 216 mutation of RDS gene. The mutation was heterozygous, and not found in 2 normal persons as controls. The alteration in the DNA sequence was identified as a heterozygous transversional change of C to T at the second nucleotide in codon 216 of RDS gene, resulting in the amino acid replacement of proline residue with leucine residue (Pro216Leu). The ocular finding of the patients with Pro216Leu mutation of RDS gene included severe visual loss and diffuse distribution of pigmentary changes with macular degeneration., Conclusions: The Pro216Leu mutation of RDS gene is found in Chinese patients with RP. The gene mutation is associated with the ocular phenotype, diffuse RP with macular degeneration.

Purpose: To investigate the genotype-phenotype correlation in Chinese patients with retinitis pigmentosa caused by rhodopsin gene mutation., Methods: On the basis of the onset of symptoms, degree of morphological changes and progression of visual disability in three (3/83) patients with identified mutations, the correlation of the phenotype with the corresponding mutations was assessed., Results: There was a certain degree of allele-specificity. Severe form of retinitis pigmentosa was found in patients with mutation in the cytoplasmic domain and mild form of retinitis pigmentosa in patients with mutation in the intradiscal domain., Conclusion: Although there is a certain relation between the mutant rhodopsin and ocular manifestation, we need to accumulate more materials before relating a rhodopsin mutation to a specific phenotype.

Objective: To establish a gene diagnosis method for X linked retinitis pigmentosa (XLRP)., Methods: Ten microsatellite markers were selected from the region where the RP2 and RP3 gene may be located at Xp21.1-p11.23. Haplotype analysis for XLRP pedigrees was used to determine the chromosome region which is RP related and whether this region was carried by the individuals we want to detect., Results: The young female who is the RP carrier or the young boy who is the pre-symptom RP patient could be determined this way in 4 XLRP family., Conclusion: Haplotype analysis for XLRP Pedigrees is useful.

Purpose: To disclose the mutation of rhodopsin and peripherin/RDS genes among Chinese patients with retinitis pigmentosa as there was no identified mutation through sequencing reported in Chinese., Methods: Genomic DNA was prepared from the peripheral lymphocytes. Gene fragments of the rhodopsin and peripherin/RDS genes were amplified by the polymerase chain reaction. The PCR products were analyzed by Heteroduplex-SSCP technique. PCR samples with aberrant migrational bands were identified through direct sequencing or cloning sequencing., Results: Three different mutations in the rhodopsin gene were found in 3 of the 83 patients with retinitis pigmentosa(Va1104Phe, Lys311Glu, Pro347Leu). Two of the three mutations have not been reported before. One of the two (heterozygous, Va1104Phe) was found in an isolated patient and the other (homozygous, Lys311Glu) in a family with autosomal recessive retinitis pigmentosa. Mutation of peripherin/RDS gene was not found in the 83 patients., Conclusion: Mutation in the rhodopsin gene is the common cause in Chinese patients with retinitis pigmentosa, either autosomal dominant, recessive or sporadic.

Objective: To clone retinitis pigmentosa region by yeast artificial chromosome (YAC) and establish the restriction enzyme physical map., Methods: The ornithine transcarbamoylase (OTC) cDNA probe, which is closely linked to the RP3 locus, was chosen to screen the X chromosome YAC library by colony in situ hybridization. Size determination, sequence taged site (STS) analysis and long range physical mapping were performed with positive YACs. The results obtained were used to map these YACs., Results: We obtained a 1.6 Mb YAC contig containing information on RP3 range, restriction enzyme sites, CpG islands location and YAC position., Conclusion: The work provides a good basis for identification and cloning of the RP3 gene.

Comprehensive genetic segregation analysis performed in 150 pedigree of retinitis pigmentosa (RP) showed that the disease manifested genetic heterogeneity. Families of the mating type Affected x Normal were autosomal dominant (AD), with 80% of penetrance and no sporadic cases. Families of the mating type Normal x Normal were 80% autosomal recessive (AR), with 20% of sporadic cases. In the present series, the RP pedigrees were AD in 13.3%, X-linked in 2.7%, AR in 67.3% and sporadic in 16.7%, and most sporadic cases were nongenetic. It was also demonstrated that, with the conventional mode of pedigree analysis, the proportions of AR and AD cases were underestimated, and the proportion of sporadic RP was overestimated.