Lack of association between APOE gene polymorphisms and amyotrophic lateral sclerosis: a comprehensive meta-analysis.

Several studies have evaluated the association between APOE gene polymorphisms and the risk for amyotrophic lateral sclerosis (ALS), with inconclusive results. The aim of our study was to further define the risk associated with carriage of the APOE alleles and development and clinical characteristics of ALS. We performed a comprehensive meta-analysis of all existing studies investigating the association between the APOE gene and ALS published up to September 2013, comprising a total of 4249 ALS patients and 10,397 controls. Pooled odds ratios (OR) were estimated using the random effect (RE) model. Results showed that the carriage of different APOE alleles had no effect on disease risk. In particular, the ϵ4 allele was not associated with a significantly increased disease risk (ϵ4 carriers vs. non-ϵ4 carriers: RE OR 1.18; 95% CI 0.91-1.53). In conclusion, our study suggests that the APOE gene does not have a significant effect in ALS aetiopathogenesis.