Tomoyo Funayama

Association of Toll-like Receptor 4 Gene Polymorphisms in Japanese Subjects With Primary Open-Angle, Normal-Tension, and Exfoliation Glaucoma

PURPOSE To determine whether polymorphisms in the Toll-like receptor 4 (TLR4) gene are associated with primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), and exfoliation glaucoma (XFG) in Japanese individuals. DESIGN Genetic association study. METHODS SETTING Multicenter study. STUDY POPULATION One hundred eighty-four unrelated Japanese patients with POAG, 365 unrelated patients with NTG, and 109 unrelated patients with XFG from 5 hospitals. PROCEDURES Genomic DNA was extracted from leukocytes of the peripheral blood, and 8 polymorphisms in the TLR4 genes were amplified by polymerase chain reaction (PCR) and directly sequenced. Allele and genotype frequencies and the inferred haplotypes were estimated. MAIN OUTCOME MEASURES Differences in allele and genotype frequencies and haplotypes between subjects with POAG, NTG, and XFG. RESULTS The allele frequency of rs2149356 of the TLR4 gene in the POAG, NTG, and XFG groups was the most significantly different from that of the control group (minor allele frequency 0.446, 0.395, 0.404, vs 0.308; P = .000058, P = .0030, and P = .015). The allele frequencies of the 5 TLR4 SNPs were higher in all of the glaucoma groups than that in the control group. The statistics of genotypes of TLR4 were approximately the same for all allele frequencies. The haplotypic frequencies with Tag SNPs studied earlier showed that only POAG was statistically significant. Other haplotypes, such as rs10759930, rs1927914, rs1927911, and rs2149356, had higher statistical significance (overall P = .00078 in POAG, overall P = .018 in NTG, and overall P = .014 in XFG). CONCLUSIONS This study demonstrated that TLR4 polymorphisms are associated with NTG in the Japanese, and they also play a role in the pathogenesis of POAG and XFG.

Genetic variants of TP53 and EPHX1 in Leber’s hereditary optic neuropathy and their relationship to age at onset

PurposeTo determine whether genetic polymorphisms of the genes for oxidative stress and apoptosis cause the clinical variability in patients with Leber’s hereditary optic neuropathy (LHON).MethodsEighty-seven unrelated Japanese LHON patients carrying the 11778 mitochondrial mutation were studied at the Keio University Hospital. Their mean age (±SD) was 25.0 ± 13.0 years with a range 3 to 65 years. Eleven polymorphisms in nine genes were studied: seven genes related to oxidative stress (SOD2, GSTT1, GSTM1, EPHX1, NQO1, p22 PHOX, and NOS3), and two genes related to apoptosis (TP53 and CD95). Each genetic polymorphism was analyzed in relation to the age at onset and the final visual acuity.ResultsAmong the oxidative stress-related polymorphisms, a significant association between Tyr113His in the EPHX1 gene and the age at onset of the disease was identified (P = 0.026). LHON patients who were homozygous for His113 developed the disease earlier than those without this genotype (21.9 vs. 27.9 years). Among the apoptosis-related polymorphisms, a significant association between Arg72Pro in the TP53 gene and the age at onset was identified (P = 0.007). LHON patients who were homozygous for Arg72 developed the disease earlier than those without this genotype (20.5 vs. 28.1 years). In addition, LHON patients with both genotypes developed the disease significantly earlier (17.5 years, P = 0.011). No associations were found between the final visual acuity and the genetic polymorphisms examined.ConclusionNuclear genetic polymorphisms related to oxidative stress or apoptosis may modify the age at onset of LHON.

Lattice Corneal Dystrophy Type III in Patients with a Homozygous L527R Mutation in the TGFBI Gene

Late-onset lattice corneal dystrophy (LCD) is associated with decreasing vision, minor recurrent epithelial erosions or no erosions at all, and lattice lines much thicker than those usually observed in LCD types I and II.A patient with this type of LCD is classified as LCD type III. Most LDC type III cases have been reported in Japanese patients, and the inheritance pattern is proposed to be autosomal recessive. However, Stock et al. reported that although LCD type IIIA resembles type III clinically, it differs in that type IIIA has an autosomal dominant inheritance pattern. A later study reported that LCD type IIIA is caused by mutations in the transforming growth factor beta-induced (TGFBI) gene. More recently, a heterozygous L527R mutation in the TGFBI gene has been reported to be the cause of late-onset LCD in six Japanese patients. Interestingly, only two of these had a family history of LCD. Hirano et al. reported that two Japanese patients with late-onset LCD also had a heterozygous L527R mutation and no family history. They clinically diagnosed LCD type III in these two patients. We present the characteristics of two patients with late-onset LCD who were homozygous for the L527R mutation.

Novel myoc Gene Mutation, Phe369leu, in Japanese Patients with Primary Open-angle Glaucoma Detected by Denaturing High-performance Liquid Chromatography

Purpose:To screen for mutations in the MYOC gene in Japanese patients with primary open-angle glaucoma (POAG) using denaturing high-performance liquid chromatography (DHPLC). Patients and Methods:Blood samples were collected from 171 patients with POAG and 100 controls from seven institutions in Japan. For high-throughput analysis, seven exonic regions were amplified by polymerase chain reaction using DNA pooled from three patients; each DNA pool was then analyzed chromatographically. For analysis of a small number of samples, 7 exonic regions were amplified separately but simultaneously with annealing at 58°C in each patient and then chromatographed, using 7 wells of the same 96-well plate per sample. When chromatographic patterns were abnormal by either method, the PCR products of the individual samples were sequenced. Results:Four glaucoma-causing mutations were identified in five POAG patients (2.9%). One missense mutation, Phe369Leu, is new; and three others, Ile360Asn, Ala363Thr, and Thr448Pro, have been reported in Japanese patients. Phe369Leu was associated with adult onset POAG. Conclusions:Mutations in the MYOC gene were demonstrated chromatographically in 2.9% of our Japanese POAG patients. The use of pooled DNAs with DHPLC analysis is a time- and labor-saving technique. All mutations detected appear to be specific to Japanese patients.

Association between open-angle glaucoma and gene polymorphism for heat-shock protein 70-1.

PurposeHeat-shock proteins (HSPs) or antibodies against them may contribute to glaucomatous optic neuropathy. We investigated the associations of HSP70-1 polymorphisms with open-angle glaucoma (OAG) in a Japanese population.MethodsIn 241 normal Japanese controls and 501 Japanese OAG patients, including 211 with primary open-angle glaucoma (POAG) and 290 with normal-tension glaucoma (NTG), two single-nucleotide polymorphisms, A−110C and G+190C, of HSP70-1 were identified by using an Invader assay and polymerase chain reaction-restriction fragment length polymorphism, respectively. Genotype distributions were compared between controls and OAG patients. Age at diagnosis, untreated maximum intraocular pressure, and visual field defects at diagnosis were examined for associations with the polymorphisms.ResultsDistribution of the A−110C genotype (AA versus AC+CC) differed significantly between controls and OAG patients (P = 0.007), POAG patients (P = 0.007), or NTG patients (P = 0.032). The genotype distribution of the G+190C polymorphism did not differ significantly between the controls and any patient group. No significant differences in the clinical characteristics of the patients were detected between genotype-defined groups by logistic regression analysis.ConclusionThe A−110C polymorphism of HSP70-1 may be associated with OAG pathogenesis in Japanese patients. Jpn J Ophthalmol 2007;51:417–423

Paraoxonase 1 gene polymorphisms influence clinical features of open-angle glaucoma

BackgroundThe purpose of this study was to determine whether genetic polymorphisms affecting high-density lipoprotein (HDL)-associated antioxidant enzymes were associated with open-angle glaucoma (OAG). The rationale for this study was that the modification of low-density lipoprotein (LDL) by HDL prevents oxidative modification which can then cause dysfunction of endothelial cells.MethodsWe studied 284 normal Japanese controls and 555 Japanese patients with OAG, including primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). The possible associations of polymorphisms of PON1/L55M, PON1/Q192R, PON2/S311C, and PAF-AH/V279F with OAG were investigated. We compared the genotype distributions and allele frequency in controls and patient groups. The age at diagnosis, intraocular pressure (IOP) at diagnosis, and visual field score at diagnosis were examined for association with polymorphisms.ResultsThe distributions of genotypes and allele frequency for the four polymorphisms were not significantly different between any patient group and controls. In NTG patients, 55M carriers of the PON1 gene were significantly older at diagnosis than 55M non-carriers (P=0.001). The IOP at diagnosis was significantly higher in glaucoma patients carrying 192R in the PON1 gene than in patients not carrying 192R (P=0.006). No significant differences were seen in clinical characteristics of OAG patients in relation to other polymorphisms.ConclusionPON1 gene polymorphisms may influence the features of Japanese patients with OAG.

Association of HK2 and NCK2 with normal tension glaucoma in the Japanese population.

Although family studies and genome-wide association studies have shown that genetic factors play a role in glaucoma, it has been difficult to identify the specific genetic variants involved. We tested 669 single nucleotide polymorphisms (SNPs) from the region of chromosome 2 that includes the GLC1B glaucoma locus for association with primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) in the Japanese population. We performed a two-stage case-control study. The first cohort consisted of 123 POAG cases, 121 NTG cases and 120 controls: the second cohort consisted of 187 POAG cases, 286 NTG cases, and 271 controls. Out of six SNPs showing significant association with POAG in the first round screening, seven SNPs were tested in the second round. Rs678350 in the HK2 gene coding sequence showed significant allelic (p = 0.0027 in Stage Two, 2.7XE-4 in meta-analysis) association with POAG, and significant allelic (p = 4.7XE-4 in Stage Two, 1.0XE-5 in meta-analysis) association with NTG. Although alleles in the TMEM182 gene did not show significant association with glaucoma in the second round, subjects with the A/A allele in TMEM182 rs869833 showed worse visual field mean deviation (p = 0.01). Even though rs2033008 in the NCK2 gene coding sequence did not show significant association in the first round, it had previously shown association with NTG so it was tested for association with NTG in round 2 (p = 0.0053 in Stage Two). Immunohistochemistry showed that both HK2 and NCK2 are expressed in the retinal ganglion cell layer. Once multi-testing was taken into account, only HK2 showed significant association with POAG and NTG in Stage Two. Our data also support previous reports of NCK2 association with NTG, and raise questions about what role TMEM182 might play in phenotypic variability. Our data suggest that HK2 may play an important role in NTG in the Japanese population.