Variants of RP1 gene in Chinese patients with autosomal dominant retinitis pigmentosa

BACKGROUND: The objective of this study was to determine the frequency and characteristics of mutations in the RP1 gene and to characterize mutations with the clinical features in the Chinese family with autosomal dominant retinitis pigmentosa (ADRP). METHODS: Forty-three affected, unrelated Chinese individuals with ADRP were recruited between 2002 and 2006. Polymerase chain reaction and direct DNA sequencing were used to screen in the entire coding region and splice sites of the RP1 gene. Cosegregation analysis and population frequency studies were performed for patients with identified mutations. The clinical features were determined by complete ophthalmologic examinations. RESULTS: The mutation detectable rate of the RP1 gene in Chinese patients with ADRP was 1/43. A missense mutation, N985Y, was identified in exon 4 of the RP1 gene in 8 affected individuals from a Chinese family with ADRP. The ophthalmic findings with an N985Y mutation were similar to those of typical retinitis pigmentosa with delayed onset after age 40 years and slow progression. In addition, a total of 9 distinct variants were detected in our study population, most of which were RP1 gene polymorphisms; the pathological significance of P903L, a novel missense mutation, was unconfirmed. INTERPRETATION: Mutations in the RP1 gene are relatively rare in Chinese patients with ADRP. In our cases, N985Y mutation segregated with the phenotype from 1 Chinese family with mild and late-onset ADRP, a finding that has not been documented in other races.     

Novel rhodopsin mutations Gly114Val and Gln184Pro in dominant retinitis pigmentosa

PURPOSE: To identify mutations in the rhodopsin gene in North American patients with autosomal dominant retinitis pigmentosa (ADRP) and to measure the proportion of cases with rhodopsin mutations. METHODS: Single-strand conformation polymorphism (SSCP) analysis and direct genomic sequencing were used to evaluate the coding region and intron splice sites of the rhodopsin gene for mutations in 91 unrelated patients. RESULTS: Nineteen patients heterozygously carried a missense change in the rhodopsin gene (six with Pro23His, two with Pro347Leu, and one each with Thr17Met, Phe45Leu, Gly51Arg, Gly89Asp, Gly114Val, Arg135Trp, Pro171Leu, Gln184Pro, Phe220Leu, Ser297Arg, and Pro347Thr). All these missense changes were previously reported as causes for ADRP except for Gly114Val, Gln184Pro, and Phe220Leu, which were evaluated further by examining the relatives of index patients. The Gly114Val and Gln184Pro alleles cosegregated with ADRP as expected if they were pathogenic. Phe220Leu did not, indicating that it is not a cause of ADRP. CONCLUSIONS: Summation of the results of cases in this study with those of 272 unrelated cases of ADRP previously evaluated by our group shows that 90 of 363 (25%) of cases were caused by rhodopsin mutations.     

Expression of the TIGR gene in the iris,ciliary body,and trabecular meshwork of the human eye

Purpose: To identify mutations in the rhodopsin ( RHO ) gene in Chinese patients with autosomal dominant retinitis pigmentosa (ADRP) and to measure the prevalence rate of RHO mutations in Chinese ADRP cases. Methods: Thirteen Chinese families with ADRP were clinically characterized. The complete coding region and intron splice sites of RHO were analyzed for mutations with single-strand conformation polymorphism (SSCP) analysis and direct genomic sequencing. Results: One of the 13 Chinese families with ADRP was found to have a new, previously unidentified RHO mutation, a change from GAG to TAG at codon 341. The mutation (E341X) results in an in-frame stop codon, leading to the truncation of the rhodopsin protein. Mutation E341X was not detected in 100 normal control individuals. Patients carrying mutation E341X reported night blindness and showed optic atrophy, vessel attenuation, and a few bone spicule-like pigments in peripheral retina at the age of 23–25 years. At the age of 30 years, visual acuity was severely impaired, peripheral visual field was greatly constricted, rod and cone ERG was not detectable, and only a slight left cone response remained. Conclusion: We have identified a novel rhodopsin mutation (E341X) in a Chinese family with ADRP. The location and character of the mutation expand the spectrum of RHO mutations causing RP. Identification of a RHO mutation in one of the 13 ADRP families studied suggests that only 7.7% of the ADRP cases in a Chinese population were caused by RHO mutations, a ratio significantly lower than that from North America or Europe.     

视网膜色素变性患者视紫红质E341ter基因突变及临床表型分析

目的 探讨常染色体显性遗传视网膜色素变性患者视紫红质基因突变及其与临床表型的关系。方法 应用聚合酶链反应（polymerase chain reaction,PCR)和单链构象多态性（single strand conformation polymorphism,SSCP)技术,对13个常染色体显性遗传视网膜色素变性家系的27例成员,进行视紫红质基因整个编码区的突变筛选,对SSCP检测有变异带的外显子PCR产物进行测序;同时应用裂隙灯、眼底镜、动静态视地和视网膜电流图（ERG）对患者进行临床检测。随机收集30例正常人进行对照检测。结果 发现1个家系患者有视紫红质E341ter突变,呈杂合子,密码子341第一个碱基由G变成T。该家系临床表现为青年期出现夜盲,视力和视野损害较重,ERG检查杆体和锥体无反应或仅有较小的锥体反应。结论 视紫红质基因突变家系的视网膜色素变性病史开始于杆体功能的丢失,进而累及锥体系统,并最终导致视功能严重丧失。视紫红质E341ter突变被认为是该家系的病因。     

Screening for mutations in the IMPDH1 gene in Japanese patients with autosomal dominant retinitis pigmentosa

PURPOSE: To determine the presence and frequency of mutations in the IMPDH1 gene in Japanese patients with autosomal dominant retinitis pigmentosa (ADRP), and to characterize the clinical characteristics of patients with the Lys238Arg mutation in the IMPDH1 gene. DESIGN: Case reports and results of DNA analysis. METHODS: All 14 coding exons of the IMPDH1 gene were directly sequenced in 96 unrelated patients with ADRP. The clinical features were determined by visual acuity, slit-lamp biomicroscopy, and kinetic visual field tests. RESULTS: Two novel mutations, a Leu227Pro and Lys238Arg, in the IMPDH1 gene were identified in two unrelated families with ADRP. The clinical features associated with the Lys238Arg mutation were an early-onset and severe retinal degeneration. CONCLUSIONS: The most commonly reported Asp226Asn mutation was not found in the Japanese population, instead two novel mutations were found. These findings suggest that mutations of the IMPDH1 gene cause ADRP in the Japanese population.     

Mutation of human retinal fascin gene (FSCN2) causes autosomal dominant retinitis pigmentosa

PURPOSE: To characterize the clinical features of 14 Japanese patients with autosomal dominant retinitis pigmentosa (ADRP) who were found to have a mutation in the FSCN2 gene. METHODS: Mutation screening by single-strand conformation polymorphism (SSCP) was performed in 120 unrelated patients with ADRP, 200 unrelated patients with autosomal recessive retinitis pigmentosa (ARRP), and 100 patients with simplex RP (SRP). The DNA fragment that showed abnormal mobility on SSCP was sequenced. The clinical features of these patients were determined by visual acuity, slit lamp biomicroscopy, electroretinography, fluorescein angiography, and kinetic visual field testing. RESULTS: A novel 208delG mutation in the FSCN2 gene was identified in 14 patients from four unrelated families with ADRP. The ophthalmic findings were typical of RP. CONCLUSIONS: The findings show that a 208delG mutation in the FSCN2 gene produces ADRP. This mutation was found in 3.3% of the patients with ADRP in Japan, which suggests that it may be relatively common in Japanese patients with ADRP.     

视网膜色素变性1基因在常染色体显性遗传视网膜色素变性家系中的突变分析

目的:研究常染色体显性遗传视网膜色素变性(autosomal dominant retinitis pigmentosa,ADRP)家系中视网膜色素变性1(retinitis pigmentosa-1,RP1)基因的突变特征及其在RP发病机制中的作用。方法:运用聚合酶链反应和直接测序方法,对6个ADRP家系的47例成员和50例对照者进行了RP1基因全编码区和邻近剪切位点的内含子区域序列突变的筛选与检测。运用单因素分析、多因素Logistic回归分析研究RP1基因点突变在RP发病中的作用。结果:ADRP家系成员和对照组RP1基因第4外显子上检测出2个变异位点。在1691和1725密码子存在杂合的两种类型的密码子(S1691P,Ser-Pro,TCT→CCT;Q1725Q,Gln-Gln,CAA→CAG)。ADRP家系成员中Ser-1691-Pro及Gln-1725-Gln位点突变率显著高于正常对照组(χ2=11.202,P<0.05)。结论:RP1基因Ser-1691-Pro及Gln-1725-Gln位点多态性可增高RP的危险性,具有潜在的致病性,考虑为ADRP家系的易感基因。     

Novel 2336-2337delCT mutation in RP1 gene in a Japanese family with autosomal dominant retinitis pigmentosa

PURPOSE: To determine the frequency and kinds of mutations in the RP1 gene, and to characterize the clinical features of a Japanese family with autosomal dominant retinitis pigmentosa (ADRP) with a novel 2336 to 2337delCT mutation in the RP1 gene. DESIGN: Case reports and results of DNA analysis. METHODS: Mutational screening by direct sequencing was performed on 96 unrelated patients with ADRP. The clinical features were determined by complete ophthalmologic examinations. RESULTS: A novel 2336 to 2337delCT mutation in the RP1 gene was identified in two patients from a Japanese family with ADRP. In addition, three families with ADRP carried a previously reported nonpathogenic Arg1933X mutation. The ophthalmic findings with a 2336 to 2337delCT mutation were similar to those of typical retinitis pigmentosa with rapid progression after age 40 years. CONCLUSIONS: The most common Arg677X mutation in the white population was not found in the Japanese population; instead a novel mutation was found.     

Molecular genetic analysis for Japanese patients with autosomal dominant retinitis pigmentosa

PURPOSE: To identify the common mutations in Japanese patients with autosomal dominant retinitis pigmentosa(ADRP), and to show that the kind and frequency of mutations depend on race. METHODS: Previously reported mutations for ADRP are summarized, and the results of screening for 120 Japanese patients with ADRP of the human retinal bascin (FSCN 2) gene are presented. Clinical features are characterized by visual acuity, slit lamp biomicroscopy, fluorescein angiography, electroretinography, and kinetic visual field-testing. RESULTS AND CONCLUSION: The Pro 23 His and Pro 347 Leu mutations in the rhodopsin gene are representative mutations for ADRP in other countries, but the mutation in the rhodopsin gene is very rare in Japanese patients with ADRP. On the other hand, a novel 208 delG mutation in the FSCN 2 gene was identified in 14 patients from 4 Japanese families with ADRP. This mutation was found in 3.3% of patients with ADRP, which suggests that this mutation might be relatively common and characteristic in Japanese patients with ADRP.     

视网膜色素变性患者特异性光感受器细胞核受体基因突变检测分析

目的 观察特异性光感受器细胞核受体(NR2E3)基因在宁夏地区视网膜色素变性(RP)患者中的突变频率及特征,探讨其在RP发病机制中的作用。方法 经检查确诊的120例RP患者纳入研究。其中,常染色体显性遗传RP (ADRP)患者33例,来自18个家系;常染色体隐性遗传RP (ARRP)患者20例,来自15个家系;散发型RP(SRP)患者67例。选取100名健康成年人作为对照组。采用聚合酶链反应(PCR)和直接测序方法,检测NR2E3基因全编码区和邻近剪切位点的内含子区域序列突变。多因素分析研究NR2E3基因突变位点对RP的作用。结果 120例RP患者NR2E3基因检测出变异位点12个。其中,非编码区5个;第4、6、7外显子上7个。12个变异位点中,新发现变异位点6个。外显子上7个变异位点中,同义突变3个;错义突变4个。统计学分析结果显示,所有变异位点均为NR2E3基因多态性。多因素Logistic回归分析显示,变异位点均与RP发生无相关性。18例ADRP先证者、67例SRP患者和正常对照组中,分别有1、3、2例NR2E3基因第4外显子上发现p.Glu121Lys变异。发生该位点变异的ADRP患者家系（NXRP-1）另外8例患者中,出现p.Glu121Lys位点变异5例,未出现变异3例。出现变异的6例患者发病年龄较未出现p.Glu121Lys位点变异的3例患者早,且较早出现明显的中心视力损害。结论 宁夏地区RP患者NR2E3基因致病突变率小于1％,NR2E3基因的p.Glu121Lys变异发生率较低。     

常染色体显性遗传视网膜色素变性患者视紫红质基因突变的研究

目的探讨常染色体显性遗传型视网膜色素变性(autosomal dominant retinitis pigmentosa,ADRP)患者视紫红质(rhodopsin,RHO)基因是否存在突变。方法应用聚合酶链反应(polymerase chain reaction,PCR)扩增RHO第1、5外显子基因片段，以限制性核酸内切酶酶切消化技术检测38个ADRP家系的57名患者和60名正常对照者RHO第58、347密码子的突变。结果1个ADRP家系的4名患者第58密码子发生点突变，另2个ADRP家系的6名患者第347密码子也出现点突变，而对照者未发现上述两种突变。结论ADRP存在分子水平的遗传异质性，某些ADRP是由于RHO基因突变所致。(中华眼底病杂志,1998,14:108-110)     

Investigation of crystallin genes in familial cataract, and report of two disease associated mutations

AIMS: Mutations of seven crystallin genes have been shown to cause familial cataract. The authors aimed to identify disease causing crystallin mutations in paediatric cataract families from south eastern Australia. METHODS: 38 families with autosomal dominant or recessive paediatric cataract were examined. Three large families were studied by linkage analysis. Candidate genes at regions providing significant LOD scores were sequenced. Single stranded conformational polymorphism (SSCP) analysis was used to screen five crystallin genes in the probands, followed by direct sequencing of observed electrophoretic shifts. Mutations predicted to affect the coding sequence were subsequently investigated in the entire pedigree. RESULTS: A LOD score of 3.72 was obtained at the gamma-crystallin locus in one pedigree. Sequencing revealed a P23T mutation of CRYGD, found to segregate with disease. A splice site mutation at the first base of intron 3 of the CRYBA1/A3 gene segregating with disease was identified by SSCP in another large family. Five polymorphisms were also detected. CONCLUSIONS: Although mutations in the five crystallin genes comprehensively screened in this study account for 38% of paediatric cataract mutations in the literature, only two causative mutations were detected in 38 pedigrees, suggesting that crystallin mutations are a relatively rare cause of the cataract phenotype in this population.     

A comprehensive survey of mutations in the OPA1 gene in patients with autosomal dominant optic atrophy

PURPOSE: To characterize the spectrum of mutations in the OPA1 gene in a large international panel of patients with autosomal dominant optic atrophy (adOA), to improve understanding of the range of functional deficits attributable to sequence variants in this gene, and to assess any genotype-phenotype correlations. METHODS: All 28 coding exons of OPA1, intron-exon splice sites, 273 bp 5' to exon 1, and two intronic regions with putative function were screened in 94 apparently unrelated white patients of European origin with adOA by single-strand conformational polymorphism (SSCP)-heteroduplex analysis and direct sequencing. Clinical data were collated, and putative mutations were tested for segregation in the respective families by SSCP analysis or direct sequencing and in 100 control chromosomes. Further characterization of selected splice site mutations was performed by RT-PCR of patient leukocyte RNA. Staining of mitochondria in leukocytes of patients and control subjects was undertaken to assess gross differences in morphology and cellular distribution. RESULTS: Twenty different mutations were detected, of which 14 were novel disease mutations (missense, nonsense, deletion-frameshift, and splice site alterations) and six were known mutations. Mutations were found in 44 (47%) of the 94 families included in the study. Ten new polymorphisms in the OPA1 gene were also identified. Mutations occur throughout the gene, with three clusters emerging: in the mitochondrial leader, in the highly conserved guanosine triphosphate (GTP)-binding domain, and in the -COOH terminus. Examination of leukocyte mitochondria from two unrelated patients with splice site mutations in OPA1 revealed no abnormalities of morphology or cellular distribution when compared with control individuals. CONCLUSIONS: This study describes 14 novel mutations in the OPA1 gene in patients with adOA, bringing the total number so far reported to 54. It is likely that many cases of adOA are due to mutations outside the coding region of OPA1 or to large-scale rearrangements. Evaluation of the mutation spectrum indicates more than one pathophysiological mechanism for adOA. Preliminary data suggests that phenotype-genotype correlation is complex, implying a role for other genetic modifying or environmental factors. No evidence was found of pathologic changes in leukocyte mitochondria of patients with adOA.     

中国视网膜色素变性相关基因研究现状

目的 分析20年来中国视网膜色素变性(RP)相关基因研究现状。方法 回顾性分析。通过检索中国知网(CNKI)中国学术文献网络出版总库、美国国家生物技术信息中心、人类基因突变数据库、人类基因组变异协会等数据库及查阅1991～2011年发表的相关文献,统计已研究的RP相关基因种类和研究结果,并与国外相关研究进行对比。结果 迄今已发现60个与RP相关的基因。我国自1991年开始开展RP相关基因的筛查。迄今为止,共有29所医院和研究机构,收集300个RP家系和1572例散发型RP患者,对17个RP相关基因进行了研究,发表RP基因突变的文献66篇,发现239个突变,其中致病性突变131个;关于基因治疗的文献有4篇。我国RP患者中,视紫红质(RHO)、特异性光感受器细胞核受体和RP1基因突变的发生率分别为2.0％、2.9％和1.0％。关于RP基因型与临床表型关系的研究较少,发表文献15篇,主要集中在ADRP致病基因RHO、视网膜变性慢(RDS)、RP1和RP三磷酸鸟苷酶调节子(RPGR,又名RP3)的突变热点区域。国外关于RP基因筛查的文献有718篇,发现2000多个突变,其中致病性突变352个;关于RP基因治疗的文献有391篇。RHO、RDS和RP1基因是导致白种人群ADRP最主要的3个基因,基因突变的发生率分别为25％～50％、8％、5％～10％。RPGR基因是导致白种人群XLRP最主要的基因,基因突变的发生率为70％～80％,其中外显子开放阅读框15的突变频率最高,约为50％～60％。结论 我国已对17个RP相关基因进行了研究,发现了131个致病性突变;RP基因治疗尚处于起步阶段。与国外研究相比存在较大差距。     

视网膜色素变性遗传致病基因peripherin/RDS的突变筛选

目的 了解中国视网膜色素变性患者（RP）中peripherin/RDS基因的突变谱及突变率。方法 应用聚合酶链-异源双链-单链构象多态性（PCR-SSCP）及DNA序列分析技术对收集的15个常染色体显性遗传视网膜色谱变性家系和55例散发视网膜色素变性患者peripherin/RDS基因的第一，第二外显子进行检测。结果 15个家系及55例散发患者未检测到peripherin/RDS基因突变。结论 本研究所检测的视网膜色素变性患者与RDS基因无关，显示视网膜色素变性的遗传异质性。     

Molecular genetics of primary congenital glaucoma in Brazil

PURPOSE: To determine the distribution of CYP1B1 gene mutations in Brazilian patients with primary congenital glaucoma (PCG). METHODS: PCG diagnosis was established by presence of buphthalmos in at least one affected eye and associated high intraocular pressures before the age of 3 years. CYP1B1 mutation screening of 52 patients with PCG was performed by SSCP and direct sequencing of PCR fragments. RESULTS: Eleven mutations, four of which are novel, were observed in 26 (50%) individuals. A new frameshift mutation (4340delG) was observed in 20.2% of all individuals screened. These individuals had early-onset, bilateral glaucoma that necessitated multiple surgical interventions. CYP1B1 mutations were twice as frequent in affected individuals of European descent as in individuals of African descent. Analysis of six intragenic single nucleotide polymorphisms (SNPs) established 5'-C-C-G-G-T-A-3' as the most common haplotype among the affected Brazilian individuals. A nonsense mutation (W57X) previously reported in an individual with Peters anomaly (compound heterozygote) was also observed in two individuals with PCG but combined with different mutations. A newly developed SSCP assay enabled us to detect all DNA mutations and polymorphisms previously detected by direct sequencing. CONCLUSIONS: Our results indicate that CYP1B1 mutations may be responsible for half of cases of PCG in the Brazilian population. The SNP haplotype 5'-C-C-G-G-T-A-3' was associated with the majority of CYP1B1 mutations. This haplotype harbors the high-activity V432 allele, which is emerging as a putative susceptibility factor in several cancers.     

常染色体显性视网膜色素变性一家系基因排除定位研究

目的对1个四代常染色体显性视网膜色素变性(autosomal dominant retinitis pigmentosa，ADRP)家系在包含已知ADRP致病基因的全部9条染色体上进行基因连锁定位。方法对家系中的所有患者进行眼科及电生理检查。在家系中对第1、3、6、7、8、11、14、17、19号染色体进行基因扫描、基因型分析及连锁分析。结果在全部9条染色体范围内未发现微卫星位点与该家系疾病表型共分离，最大lod score小于-2。结论此家系中排除了目前已知的所有ADRP位点，此家系中应存在新的ADRP连锁位点位于上述9条染色体之外。     

Novel cytochrome P4501B1 (CYP1B1) gene mutations in Japanese patients with primary congenital glaucoma

PURPOSE: To investigate CYP1B1 gene mutations in Japanese patients with primary congenital glaucoma (PCG). METHODS: Sixty-five unrelated Japanese patients with PCG were screened by PCR-single-strand conformational polymorphism (SSCP) analysis followed by direct sequencing. No patients were offspring of consanguineous marriages, a common occurrence among patients in previous reports. PCG haplotypes were constructed with intragenic polymorphisms in affected individuals. Three-dimensional atomic structures of human CYP1B1 and four mutant CYP1B1 sequences representing missense mutations were assembled using homology modeling and were regularized by an energy-minimization procedure. RESULTS: Eleven novel mutations, including seven definite and four probable mutations, were detected in 13 (20%) of the 65 unrelated patients. Of the seven definite mutations, three were predicted to truncate the CYP1B1 open reading frame. The other four were missense mutations (Asp192Val, Ala330Phe, Val364Met, and Arg444Gln), all located in conserved core structures determining proper folding and heme-binding ability of cytochrome P450 molecules. Molecular modeling demonstrated that two of four mutations in positions 330 and 364 were structurally neutral, but Arg444Gln caused significant structural change. Of the four probable mutations, three were missense (Val198Ile, Val320Leu, and Glu499Gly); the other was a base substitution in the noncoding region of exon 1. CONCLUSIONS: The 11 varied CYP1B1 mutations found in 13 unrelated Japanese patients with sporadic occurrence of PCG represent an allelic heterogeneity and may be unique to a specific population.     

Lack of association of mutations of the bestrophin gene with age-related macular degeneration in non-familial Japanese patients

BACKGROUND: Heterozygous mutations of the bestrophin gene are associated with Best macular dystrophy (BMD). The bestrophin gene is specifically expressed in the retinal pigment epithelium. BMD is a hereditary form of macular degeneration that may develop subretinal neovascularisation similar to the wet type of age-related macular degeneration (AMD). PURPOSE: To study whether mutations of the bestrophin gene occur in non-familial Japanese AMD patients. METHODS: A total of 85 non-familial AMD patients (average age 67.5 years; 71 male, 14 female) diagnosed by indocyanine green angiography were screened. Among them, 69 patients (81 %) were classified as having wet type AMD. Genomic DNA was purified from the total blood and used as the template for polymerase chain reaction (PCR). All the exons of bestrophin gene were amplified by PCR. Mutation analysis was performed by SSCP using the ABI Prism 310 Genetic Analyzer (Perkin Elmer). Nucleotide sequence was determined by direct sequencing of the PCR amplicons. As the control, 105 non-AMD patients (average age 62.0 years; 52 male, 53 female) were screened by the same method. RESULTS: Only one AMD patient had a specific polymorphism in exon 2, but no mutations leading to amino acid substitutions were found. In exon 2 and 3, two further polymorphisms were detected in all AMD patients as well as normal controls. CONCLUSION: No mutations were found in the bestrophin gene in nonfamilial Japanese patients with AMD or in normal controls.     

ATP binding cassette transporter retina genotypes and age related macular degeneration: an analysis on exudative non-familial Japanese patients

AIM: To determine whether mutations in the Stargardt's disease gene, ATP binding cassette transporter retina (ABCR) affect the occurrence of age related macular degeneration (AMD) in Japanese non-familial patients. METHODS: 80 unrelated Japanese patients with AMD (67 males and 13 females; mean age, 67.2 years) diagnosed by indocyanine green angiography and 100 age matched control subjects were studied. Among the AMD patients, 70 (87.5%) had choroidal neovascularisation of exudative type. Genomic DNA was purified from the total blood and 10 exons (exons 11, 23, 29, 32, 34, 37, 41, 43, 44, and 49) that have been reported to contain AMD associated mutations were amplified by polymerase chain reaction (PCR). The amplicons were analysed by the single strand conformation polymorphism (SSCP) method. The nucleotide sequencing of the amplicons was determined when necessary. RESULTS: Of the 10 exons, aberrant patterns of SSCP were detected in three exons-exons 29, 41, and 43. In exon 29, an aberrant pattern was found in seven of 80 patients (8.8%) and eight of 100 controls (8%). Sequencing of the PCR products revealed a heterozygous T1428M mutation which has been previously reported as one of the AMD associated mutations. Statistical analysis showed that there was no significant difference in the occurrence of this mutation between these AMD patients and the control groups (p = 0.86). In exons 23, 41, and 43, polymorphisms and sequence variations were found. CONCLUSION: No data to support the association between the ABCR gene mutations and AMD of Japanese patients, especially that of the exudative type, were obtained in this molecular genetic analysis.