PURPOSE: Polymorphic variation in genes involved in regulation of the complement system has been implicated as a major cause of genetic risk, in addition to the LOC387715/HTRA1 locus and other environmental influences. Previous studies have identified polymorphisms in the complement component 2 (CC2) and factor B (CFB) genes, as potential functional variants associated with AMD, in particular CFB R32Q and CC2 rs547154, both of which share strong linkage disequilibrium (LD). METHODS: Data derived from the HapMap Project were used to select 18 haplotype-tagging SNPs across the extended CC2/CFB region for genotyping, to measure the strength of LD in 318 patients with neovascular AMD and 243 age-matched control subjects to identify additional potential functional variants in addition to those originally reported. RESULTS: Strong LD was measured across this region as far as the superkiller viralicidic activity 2-like gene (SKIV2L). Nine SNPs were identified to be significantly associated with the genetic effect observed at this locus. Of these, a nonsynonymous coding variant SKIV2L R151Q (rs438999; OR, 0.48; 95% confidence interval [CI], 0.31-0.74; P<0.001), was in strong LD with CFB R32Q, rs641153 (r(2)=0.95) and may exert a functional effect. When assessed within a logistic regression model measuring the effects of genetic variation at the CFH and LOC387715/HTRA1 loci and smoking, the effect remained significant (OR, 0.38; 95% CI, 0.22-0.65; P<0.001). Additional variation identified within this region may also confer a weaker but independent effect and implicate additional genes within the pathogenesis of AMD. CONCLUSIONS: Because of the high level of LD within the extended CC2/CFB region, variation within SKIV2L may exert a functional effect in AMD.
PURPOSE: Polymorphic variation in genes involved in regulation of the complement system has been implicated as a major cause of genetic risk, in addition to the LOC387715/HTRA1 locus and other environmental influences. Previous studies have identified polymorphisms in the complement component 2 (CC2) and factor B (CFB) genes, as potential functional variants associated with AMD, in particular CFB R32Q and CC2rs547154, both of which share strong linkage disequilibrium (LD). METHODS: Data derived from the HapMap Project were used to select 18 haplotype-tagging SNPs across the extended CC2/CFB region for genotyping, to measure the strength of LD in 318 patients with neovascular AMD and 243 age-matched control subjects to identify additional potential functional variants in addition to those originally reported. RESULTS: Strong LD was measured across this region as far as the superkiller viralicidic activity 2-like gene (SKIV2L). Nine SNPs were identified to be significantly associated with the genetic effect observed at this locus. Of these, a nonsynonymous coding variant SKIV2L R151Q (rs438999; OR, 0.48; 95% confidence interval [CI], 0.31-0.74; P<0.001), was in strong LD with CFB R32Q, rs641153 (r(2)=0.95) and may exert a functional effect. When assessed within a logistic regression model measuring the effects of genetic variation at the CFH and LOC387715/HTRA1 loci and smoking, the effect remained significant (OR, 0.38; 95% CI, 0.22-0.65; P<0.001). Additional variation identified within this region may also confer a weaker but independent effect and implicate additional genes within the pathogenesis of AMD. CONCLUSIONS: Because of the high level of LD within the extended CC2/CFB region, variation within SKIV2L may exert a functional effect in AMD.
Authors: Susan D Vogt; Christine A Curcio; Lan Wang; Chuan-Ming Li; Gerald McGwin; Nancy E Medeiros; Nancy J Philp; James A Kimble; Russell W Read Journal: Exp Eye Res Date: 2011-06-12 Impact factor: 3.467
Authors: Nathan G Lambert; Hanan ElShelmani; Malkit K Singh; Fiona C Mansergh; Michael A Wride; Maximilian Padilla; David Keegan; Ruth E Hogg; Balamurali K Ambati Journal: Prog Retin Eye Res Date: 2016-05-06 Impact factor: 21.198
Authors: Delu Song; Levi N Kanu; Yafeng Li; Kristen L Kelly; Rupak K Bhuyan; Tomas Aleman; Jessica I W Morgan; Joshua L Dunaief Journal: Exp Eye Res Date: 2016-08-23 Impact factor: 3.467