Lack of association between the Angiogenin (ANG) rs11701 polymorphism and amyotrophic lateral sclerosis risk: a meta-analysis

To perform a meta-analysis to help resolve the controversy of whether the Angiogenin (ANG) rs11701 polymorphism is associated with amyotrophic lateral sclerosis (ALS) risk. A literature search of PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure, Wanfang and SinoMed was conducted for eligible studies published up to Jun 5, 2015. The strength of the association between the polymorphism and ALS susceptibility was estimated by odds ratio (OR) and associated 95 % confidence interval (CI). The pooled ORs were assessed for the dominant model (TG + GG vs. TT), recessive model (GG vs. TG + TT), heterozygote model (TG vs. TT), homozygote model (GG vs. TT) and allele model (G vs. T). Ten eligible articles were identified, which reported 14 case-control studies and a total of 5807 cases and 3861 controls. Analysis of pooled ORs and 95 % CIs suggested lack of association between the ANG rs11701 polymorphism and risk for ALS, Familial ALS or Sporadic ALS (all p value for z test >0.05). A stratified analysis according to Caucasian or Han Chinese origin further showed that the rs11701 polymorphism was not associated with the disease risk in Caucasians or Han Chinese. There is no difference in the polymorphism frequencies between patients with FALS or SALS. The ANG rs11701 polymorphism was not associated with risk for ALS, FALS or SALS. There is no difference between the polymorphism frequencies in patients with FALS or SALS. Further well-designed studies with larger populations are required to validate these results.