Macular Degeneration: Swaroop A

Kanda A, Abecasis G, Swaroop A. · No affiliation provided · Br J Ophthalmol. · Pubmed #18369057 No free full text.

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Swaroop A, Branham KE, Chen W, Abecasis G. · Department of Ophthalmology, University of Michigan, Ann Arbor, MI 48105, USA. · Hum Mol Genet. · Pubmed #17911160 links to  free full text

Abstract: Age-related macular degeneration (AMD) is a progressive neurodegenerative disease, which affects quality of life for millions of elderly individuals worldwide. AMD is associated with a diverse spectrum of clinical phenotypes, all of which include the death of photoreceptors in the central part of the human retina (called the macula). Tremendous progress has been made in identifying genetic susceptibility variants for AMD. Variants at chromosome 1q32 (in the region of CFH) and 10q26 (LOC387715/ARMS2) account for a large part of the genetic risk to AMD and have been validated in numerous studies. In addition, susceptibility variants at other loci, several as yet unidentified, make substantial cumulative contribution to genetic risk for AMD; among these, multiple studies support the role of variants in APOE and C2/BF genes. Genome-wide association and re-sequencing projects, together with gene-environment interaction studies, are expected to further define the causal relationships that connect genetic variants to AMD pathogenesis and should assist in better design of prevention and intervention.

Zack DJ, Dean M, Molday RS, Nathans J, Redmond TM, Stone EM, Swaroop A, Valle D, Weber BH. · Departments of Ophthalmology, Molecular Biology and Genetics, and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. · Mol Vis. · Pubmed #10562654 links to  free full text

Abstract: Age-related macular degeneration (AMD) is increasingly recognized as a complex genetic disorder in which one or more genes contribute to an individual's susceptibility for developing the condition. Twin and family studies as well as population-based genetic epidemiologic methods have convincingly demonstrated the importance of genetics in AMD, though the extent of heritability, the number of genes involved, and the phenotypic and genetic heterogeneity of the condition remain unresolved. The extent to which other hereditary macular dystrophies such as Stargardts disease, familial radial drusen (malattia leventinese), Best's disease, and peripherin/RDS-related dystrophy are related to AMD remains unclear. Alzheimer's disease, another late onset, heterogeneous degenerative disorder of the central nervous system, offers a valuable model for identifying the issues that confront AMD genetics.

Edwards AO, Chen D, Fridley BL, James KM, Wu Y, Abecasis G, Swaroop A, Othman M, Branham K, Iyengar SK, Sivakumaran TA, Klein R, Klein BE, Tosakulwong N. · Department of Ophthalmology, Mayor Clinic, Rochester, MN 55905, USA. · Invest Ophthalmol Vis Sci. · Pubmed #18385087 links to  free full text

Abstract: PURPOSE: Evidence from genetic-association studies in conjunction with the demonstration of complement deposition in the retina and choroid implicates noncellular pathways of innate immunity in the pathogenesis of age-related macular degeneration (AMD). The purpose of this study was to determine whether common variation in the 10 human toll-like receptors (TLRs) alters the risk of AMD. METHODS: Sixty-eight SNPs were iteratively genotyped across the TLR genes in a cohort of 577 subjects, with and without AMD. Two additional cohorts were used for replication studies. Standard genetic-association methods were used to analyze the results for association with disease and interaction with other loci. RESULTS: Coding SNPs in TLR3 (rs3775291) and TLR7 (rs179008) showed association with AMD in one group (P = 0.01 and P = 0.02, respectively) before correction for multiple testing. For both SNPs, the association with AMD arose due to an excess of heterozygotes compared with homozygotes for the major allele. The two coding SNPs were not associated with AMD in another case-control cohort or an extended-family cohort. Although an intronic SNP in TLR4 was associated marginally with AMD (P = 0.03), it was not possible to replicate a previous association with the rare coding SNP D299G in this gene (P = 0.6). CONCLUSIONS: Although borderline support for association between polymorphisms in TLR genes and AMD was reported for some cohorts, these initial observations of coding SNPs in TLR3, TLR4, and TLR7 were not replicated. TLR variants are unlikely to have a major impact on overall AMD risk, and the common variants studied were not associated with AMD.

Kanda A, Chen W, Othman M, Branham KE, Brooks M, Khanna R, He S, Lyons R, Abecasis GR, Swaroop A. · Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA. · Proc Natl Acad Sci U S A. · Pubmed #17884985 links to  free full text

Abstract: Genetic variants at chromosomes 1q31-32 and 10q26 are strongly associated with susceptibility to age-related macular degeneration (AMD), a common blinding disease of the elderly. We demonstrate, by evaluating 45 tag SNPs spanning HTRA1, PLEKHA1, and predicted gene LOC387715/ARMS2, that rs10490924 SNP alone, or a variant in strong linkage disequilibrium, can explain the bulk of association between the 10q26 chromosomal region and AMD. A previously suggested causal SNP, rs11200638, and other examined SNPs in the region are only indirectly associated with the disease. Contrary to previous reports, we show that rs11200638 SNP has no significant impact on HTRA1 promoter activity in three different cell lines, and HTRA1 mRNA expression exhibits no significant change between control and AMD retinas. However, SNP rs10490924 shows the strongest association with AMD (P = 5.3 x 10(-30)), revealing an estimated relative risk of 2.66 for GT heterozygotes and 7.05 for TT homozygotes. The rs10490924 SNP results in nonsynonymous A69S alteration in the predicted protein LOC387715/ARMS2, which has a highly conserved ortholog in chimpanzee, but not in other vertebrate sequences. We demonstrate that LOC387715/ARMS2 mRNA is detected in the human retina and various cell lines and encodes a 12-kDa protein, which localizes to the mitochondrial outer membrane when expressed in mammalian cells. We propose that rs10490924 represents a major susceptibility variant for AMD at 10q26. A likely biological mechanism is that the A69S change in the LOC387715/ARMS2 protein affects its presumptive function in mitochondria.

Duncan JL, Zhang Y, Gandhi J, Nakanishi C, Othman M, Branham KE, Swaroop A, Roorda A. · Department of Ophthalmology, University of California, San Francisco School of Medicine, San Francisco, California 94143-0730, USA. · Invest Ophthalmol Vis Sci. · Pubmed #17591900 links to  free full text

Abstract: PURPOSE: To investigate macular photoreceptor structure in patients with inherited retinal degeneration using high-resolution images and to correlate the findings with clinical phenotypes and genetic mutations. METHODS: Adaptive optics scanning laser ophthalmoscopy (AOSLO) images of photoreceptors were obtained in 16 eyes: five with retinitis pigmentosa (RP), three with cone-rod dystrophy (CRD), and eight without retinal disease. A quadratic model was used to illustrate cone spacing as a function of retinal eccentricity. Cone spacing at 1 degrees eccentricity was compared with standard measures of central visual function, including best-corrected visual acuity (BCVA), foveal threshold, and multifocal electroretinogram (mfERG) amplitude and timing. Intervisit variations were studied in one patient with RP and one patient with CRD. Screening of candidate disease genes identified mutations in two patients, one with RP (a rhodopsin mutation) and the other with CRD (a novel RPGR-ORF15 mutation). RESULTS: Cone spacing values were significantly different from normal for patients with RP (P = 0.01) and CRD (P < 0.0001) and demonstrated a statistically significant correlation with foveal threshold (P = 0.0003), BCVA (P = 0.01), and mfERG amplitude (P = 0.008). Although many RP patients showed normal cone spacing within 1 degrees of fixation, cones could not be unambiguously identified in several retinal regions. Cone spacing increased in all CRD patients, even those with early disease. Little variation was observed in cone spacing measured during two sessions fewer than 8 days apart. CONCLUSIONS: AOSLO images can be used to study macular cones with high resolution in patients with retinal degeneration. The authors present the first report of cone structure in vivo in patients with mutations in rhodopsin and RPGR-ORF15 and show that macular cones display distinct characteristics, depending on the underlying disease. AOSLO imaging, therefore, can provide new insight into possible mechanisms of cone vision loss in patients with retinal degeneration.

Ronan S, Nusinowitz S, Swaroop A, Heckenlively JR. · Department of Ophthalmology and Visual Science, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA. · Trans Am Ophthalmol Soc. · Pubmed #17471344 links to  free full text

Abstract: PURPOSE: To test if patients with age-related macular degeneration (AMD) have normal panretinal function using standardized full-field electroretinograms (ERGs). METHODS: This is a retrospective study evaluating electroretinographic studies performed in patients with AMD to assess their panretinal function. Fifty-two individuals 55 years or older had standardized ERG testing and fundus photographs. RESULTS: The study group was aged 57 to 93 years old with a mean of 75.7, and the controls ranged from 79 to 87 years with a mean of 81.4. On average, the photopic, scotopic, dark-adapted bright-flash, and flicker function response amplitudes are lower with longer implicit times in the study group than the controls. The most pronounced differences were seen with the bright-flash dark-adapted a-waves and the photopic b-wave amplitudes. Forty-three of 104 eyes had abnormal photopic b-wave ERGs of more than 2 SD compared to controls. The mean of the photopic b-wave amplitudes for the study group was 76.7 +/- 36.2 muV (1 SD) compared to 91.4 +/- 16.9 muV (1 SD) for the control group. This finding was statistically significant with P = .0269 by the Student t test and P = .0336 by the Wilcoxon test. CONCLUSIONS: There is a subgroup of AMD patients with a panretinal cone dysfunction on ERG in association with their macular degeneration. Previous studies have shown varied results when looking at ERG changes in AMD, likely reflecting the underlying complexity of this disorder. Using standardized ERG to identify a more homogeneous subgroup of AMD patients with panretinal dysfunction will aid in better characterizing subtypes clinically and is likely to be valuable in identifying new genes contributing to AMD.

Li M, Atmaca-Sonmez P, Othman M, Branham KE, Khanna R, Wade MS, Li Y, Liang L, Zareparsi S, Swaroop A, Abecasis GR. · Department of Biostatistics, 1420 Washington Heights, University of Michigan, Ann Arbor, Michigan 48109, USA. · Nat Genet. · Pubmed #16936733 links to  free full text

Abstract: In developed countries, age-related macular degeneration is a common cause of blindness in the elderly. A common polymorphism, encoding the sequence variation Y402H in complement factor H (CFH), has been strongly associated with disease susceptibility. Here, we examined 84 polymorphisms in and around CFH in 726 affected individuals (including 544 unrelated individuals) and 268 unrelated controls. In this sample, 20 of these polymorphisms showed stronger association with disease susceptibility than the Y402H variant. Further, no single polymorphism could account for the contribution of the CFH locus to disease susceptibility. Instead, multiple polymorphisms defined a set of four common haplotypes (of which two were associated with disease susceptibility and two seemed to be protective) and multiple rare haplotypes (associated with increased susceptibility in aggregate). Our results suggest that there are multiple disease susceptibility alleles in the region and that noncoding CFH variants play a role in disease susceptibility.

Vine AK, Stader J, Branham K, Musch DC, Swaroop A. · Department of Ophthalmology, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105, USA. · Ophthalmology. · Pubmed #16225921 No free full text.

Abstract: PURPOSE: To measure and contrast 2 biomarkers of cardiovascular disease, C-reactive protein (CRP) and plasma homocysteine, in individuals with age-related macular degeneration (AMD) and control individuals without AMD. DESIGN: Case-control study. PARTICIPANTS: Seventy-nine affected individuals and 77 unaffected individuals from the AMD Genetic Study Group returned to obtain CRP and homocysteine levels. METHODS: Both affected and unaffected individuals underwent testing for CRP and homocysteine. A detailed cardiovascular history was taken. MAIN OUTCOME MEASURES: Mean CRP and homocysteine levels in affected and unaffected individuals. RESULTS: Mean CRP levels for affected and unaffected individuals were 3.42 and 2.30 mg/l, respectively (P = 0.03). Mean homocysteine levels for affected and unaffected individuals were 11.72 and 8.88 micromol/l, respectively (P<0.0001). In logistic regression models, older age, higher CRP, and higher homocysteine were risk factors for AMD. There were no significant differences between cases and controls in terms of gender, diabetes, hypertension, use of statin drugs, and smoking. The control group was significantly younger and had a lower rate of vitamin usage than the affected group. CONCLUSIONS: Elevated CRP and homocysteine levels are associated with AMD and implicate the role of chronic inflammation and atherosclerosis.

Fisher SA, Abecasis GR, Yashar BM, Zareparsi S, Swaroop A, Iyengar SK, Klein BE, Klein R, Lee KE, Majewski J, Schultz DW, Klein ML, Seddon JM, Santangelo SL, Weeks DE, Conley YP, Mah TS, Schmidt S, Haines JL, Pericak-Vance MA, Gorin MB, Schulz HL, Pardi F, Lewis CM, Weber BH. · Department of Medical and Molecular Genetics, Guy's, King's and St Thomas' School of Medicine, King's College London, London SE1 9RT, UK. · Hum Mol Genet. · Pubmed #15987700 links to  free full text

Abstract: A genetic contribution to the development of age-related macular degeneration (AMD) is well established. Several genome-wide linkage studies have identified a number of putative susceptibility loci for AMD but only a few of these regions have been replicated in independent studies. Here, we perform a meta-analysis of six AMD genome screens using the genome-scan meta-analysis method, which allows linkage results from several studies to be combined, providing greater power to identify regions that show only weak evidence for linkage in individual studies. Results from non-parametric analysis for a broad AMD clinical phenotype (including two studies with quantitative traits) were extracted. For each study, 120 genomic bins of approximately 30 cM were defined and ranked according to maximum evidence for linkage within each bin. Bin ranks were weighted according to study size and summed across all studies; the summed rank (SR) for each bin was assessed empirically for significance using permutation methods. A high SR indicates a region with consistent evidence for linkage across studies. The strongest evidence for an AMD susceptibility locus was found on chromosome 10q26 where genome-wide significant linkage was observed (P=0.00025). Several other regions met the empirical significance criteria for bins likely to contain linked loci including adjacent pairs of bins on chromosomes 1q, 2p, 3p and 16. Several of the regions identified here showed only weak evidence for linkage in the individual studies. These results will help prioritize regions for future positional and functional candidate gene studies in AMD.

Zareparsi S, Branham KE, Li M, Shah S, Klein RJ, Ott J, Hoh J, Abecasis GR, Swaroop A. · Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA. · Am J Hum Genet. · Pubmed #15895326 links to  free full text

Abstract: Using a large sample of cases and controls from a single center, we show that a T-->C substitution in exon 9 (Y402H) of the complement factor H gene is strongly associated with susceptibility to age-related macular degeneration, the most common cause of blindness in the elderly. Frequency of the C allele was 0.61 in cases, versus 0.34 in age-matched controls (P<1x10(-24)). Genotype frequencies also differ markedly between cases and controls (chi2=112.68 [2 degrees of freedom]; P<1x10(-24)). A multiplicative model fits the data well, and we estimate the population frequency of the high-risk C allele to be 0.39 (95% confidence interval 0.36-0.42) and the genotype relative risk to be 2.44 (95% confidence interval 2.08-2.83) for TC heterozygotes and 5.93 (95% confidence interval 4.33-8.02) for CC homozygotes.

Zareparsi S, Buraczynska M, Branham KE, Shah S, Eng D, Li M, Pawar H, Yashar BM, Moroi SE, Lichter PR, Petty HR, Richards JE, Abecasis GR, Elner VM, Swaroop A. · Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA. · Hum Mol Genet. · Pubmed #15829498 links to  free full text

Abstract: Age-related macular degeneration (AMD) is a genetically heterogeneous disease that leads to progressive and irreversible vision loss among the elderly. Inflammation, oxidative damage, cholesterol metabolism and/or impaired function of retinal pigment epithelium (RPE) have been implicated in AMD pathogenesis. We examined toll-like receptor 4 (TLR4) as a candidate gene for AMD susceptibility because: (i) the TLR4 gene is located on chromosome 9q32-33, a region exhibiting evidence of linkage to AMD in three independent reports; (ii) the TLR4-D299G variant is associated with reduced risk of atherosclerosis, a chronic inflammatory disease with subendothelial accumulation; (iii) the TLR4 is not only a key mediator of proinflammatory signaling pathways but also linked to regulation of cholesterol efflux and (iv) the TLR4 participates in phagocytosis of photoreceptor outer segments by the RPE. We examined D299G and T399I variants of TLR4 in a sample of 667 unrelated AMD patients and 439 unrelated controls, all of Caucasian ancestry. Multiple logistic regression demonstrated an increased risk of AMD in carriers of the G allele at TLR4 residue 299 (odds ratio=2.65, P=0.025), but lack of an independent effect by T399I variant. TLR4-D299G showed an additive effect on AMD risk (odds ratio=4.13, P=0.002) with allelic variants of apolipoprotein E (APOE) and ATP-binding cassette transporter-1 (ABCA1), two genes involved in cholesterol efflux. Interestingly, the effect of TLR4, APOE and ABCA1 variants on AMD susceptibility was opposite to that of association with atherosclerosis risk. Our data provide evidence of a link between multiple diverse mechanisms underlying AMD pathogenesis.

Zareparsi S, Reddick AC, Branham KE, Moore KB, Jessup L, Thoms S, Smith-Wheelock M, Yashar BM, Swaroop A. · Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan 48105, USA. · Invest Ophthalmol Vis Sci. · Pubmed #15111581 links to  free full text

Abstract: PURPOSE: To examine the effect of apolipoprotein E (APOE) alleles on age-related macular degeneration (AMD) risk and on age at diagnosis of AMD in a large patient cohort recruited from a single center. METHODS: The frequency of APOE alleles was analyzed in 632 unrelated AMD patients and 206 unrelated controls, all of whom were of white ancestry. The presence or absence of disease symptoms in all patients and controls was based on clinical examination and/or ophthalmic records. The association with APOE was explored in the context of AMD subtypes, family history status, possible interaction with smoking, and distribution of age at diagnosis of AMD. RESULTS: The frequency of the epsilon4 allele was significantly reduced in patients compared with controls (0.10 vs. 0.14, P < or = 0.02). Gender- and age-adjusted odds ratios indicated that epsilon4-carriers have significantly lower risk of developing AMD compared to epsilon3epsilon3 subjects (OR = 0.55, 95% CI: 0.37-0.82, P = 0.004). In the cohort, AMD patients with a positive family history exhibited a significant 3.5 years earlier age at diagnosis (P = 0.001); however, APOE alleles did not appear to modulate the age at diagnosis of AMD. CONCLUSIONS: The association between the APOE-epsilon4 allele and a reduced risk of AMD was established in a large cohort with sufficient statistical power. How distinct APOE alleles affect AMD susceptibility warrants further investigation.

Abecasis GR, Yashar BM, Zhao Y, Ghiasvand NM, Zareparsi S, Branham KE, Reddick AC, Trager EH, Yoshida S, Bahling J, Filippova E, Elner S, Johnson MW, Vine AK, Sieving PA, Jacobson SG, Richards JE, Swaroop A. · Department of Biostatistics, University of Michigan, Ann Arbor, MI 48105, USA. · Am J Hum Genet. · Pubmed #14968411 links to  free full text

Abstract: Age-related macular degeneration (AMD) is a complex multifactorial disease that affects the central region of the retina. AMD is clinically heterogeneous, leading to geographic atrophy (GA) and/or choroidal neovascularization (CNV) at advanced stages. Considerable data exists in support of a genetic predisposition for AMD. Recent linkage studies have provided evidence in favor of several AMD susceptibility loci. We have performed a high-resolution (5-cM) genome scan of 412 affected relative pairs that were enriched for late-stage disease (GA and/or CNV). Nonparametric linkage analysis was performed using two different diagnostic criteria and also by dividing the affected individuals according to GA or CNV phenotype. Our results demonstrate evidence of linkage in regions that were suggested in at least one previous study at chromosomes 1q (236-240 cM in the Marshfield genetic map), 5p (40-50 cM), and 9q (111 cM). Multipoint analysis of affected relatives with CNV provided evidence of additional susceptibility loci on chromosomes 2p (10 cM) and 22q (25 cM). A recently identified Gln5345Arg change in HEMICENTIN-1 on chromosome 1q25 was not detected in 274 affected members in the restricted group with AMD, 346 additional patients with AMD, and 237 unaffected controls. Our results consolidate the chromosomal locations of several AMD susceptibility loci and, together with previous reports, should facilitate the search for disease-associated sequence variants.

Hayward C, Shu X, Cideciyan AV, Lennon A, Barran P, Zareparsi S, Sawyer L, Hendry G, Dhillon B, Milam AH, Luthert PJ, Swaroop A, Hastie ND, Jacobson SG, Wright AF. · MRC Human Genetics Unit, Western General Hospital, Edinburgh, UK. · Hum Mol Genet. · Pubmed #12944416 links to  free full text

Abstract: A primary feature of age-related macular degeneration (AMD) is the presence of extracellular deposits between the retinal pigment epithelium (RPE) and underlying Bruch's membrane, leading to RPE dysfunction, photoreceptor death and severe visual loss. AMD accounts for about 50% of blind registrations in Western countries and is a common, genetically complex disorder. Very little is known regarding its molecular basis. Late-onset retinal degeneration (L-ORD) is an autosomal dominant disorder with striking clinical and pathological similarity to AMD. Here we show that L-ORD is genetically heterogeneous and that a proposed founder mutation in the CTRP5 (C1QTNF5) gene, which encodes a novel short-chain collagen, changes a highly conserved serine to arginine (Ser163Arg) in 7/14 L-ORD families and 0/1000 control individuals. The mutation occurs in the gC1q domain of CTRP5 and results in abnormal high molecular weight aggregate formation which may alter its higher-order structure and interactions. These results indicate a novel disease mechanism involving abnormal adhesion between RPE and Bruch's membrane.

Yoshida S, Yashar BM, Hiriyanna S, Swaroop A. · Department of Ophthalmology and Visual Sciences, W. K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105, USA. · Invest Ophthalmol Vis Sci. · Pubmed #12147584 links to  free full text

Abstract: PURPOSE: To develop gene expression profiles of young and elderly human retinas and identify candidate genes for aging-associated retinal diseases. METHODS: Gene microarray slides containing 2400 human genes (primarily neuronal) were hybridized to biotin or dinitrophenyl (DNP)-labeled target cDNAs that were synthesized using total RNAs from young (13-14 years) and elderly (62-74 years) human retinas. Hybridization signals were visualized with cyanine (Cy)-5 or Cy-3 fluorescent reporter molecules, and the fluorescence intensities of the images were analyzed by computer. Northern blot analysis and real-time quantitative reverse transcription PCR (qRT-PCR) were performed to validate the microarray results. RESULTS: Of the 2400 genes represented on the microarray slides, more than 50% hybridized to the retinal cDNA targets. Expression of a majority of these genes was not altered during aging; nonetheless, changes in the expression of 24 genes were detected between young and elderly retinas. These genes could be clustered into four categories: energy metabolism, stress response, cell growth, and neuronal transmission/signaling. Northern blot analysis and qRT-PCR results confirmed the changes in expression of 8 of 10 genes examined. CONCLUSIONS: Using commercially available slide microarrays, the authors show that aging of the human retina is associated with changes in patterns of gene expression. This analysis suggests that pathways involved in stress response and energy metabolism play key roles in retinal aging. These studies demonstrate the utility of gene microarrays in identifying global patterns of retinal gene expression and lay the foundation for future studies defining the genetic basis of aging-associated retinal diseases, such as age-related macular degeneration.

Ayyagari R, Zhang K, Hutchinson A, Yu Z, Swaroop A, Kakuk LE, Seddon JM, Bernstein PS, Lewis RA, Tammur J, Yang Z, Li Y, Zhang H, Yashar BM, Liu J, Petrukhin K, Sieving PA, Allikmets R. · Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA. · Ophthalmic Genet. · Pubmed #11803489 No free full text.

Abstract: Stargardt-like macular degeneration (STGD(3)) and autosomal dominant macular degeneration (adMD) share phenotypic characters with atrophic age-related macular degeneration (AMD). Mutations in a photoreceptor cell-specific factor involved in the elongation of very long chain fatty acids (ELOVL(4)) were shown to be associated with STGD(3), adMD, and pattern dystrophy. We screened 778 patients with AMD and 551 age-matched controls to define the role of sequence variants in the ELOVL(4) gene in age-related macular degeneration. We detected three sequence variants in the non-coding region and eight variants in the coding region. No statistically significant association was observed between sequence variants in the ELOVL(4) gene and susceptibility to AMD. However, for the detection of modest effects of multiple alleles in a complex disease, the analysis of larger cohorts of patients may be required.

Edwards AO, Swaroop A, Seddon JM. · No affiliation provided · N Engl J Med. · Pubmed #19469037 No free full text.

This publication has no abstract.