Association of α2-macroglobulin polymorphisms and Alzheimer disease in Mainland Han Chinese

This study used case-control method to investigate roles of two alpha2-macroglobulin (A2M) polymorphisms, a 5-bp insertion/deletion (A2M-I/D) and an A --> G substitution (A2M-A/G), in the development of sporadic Alzheimer disease (AD) in Mainland Han Chinese. Our results showed a trend of lower D-carrying genotype frequency in APOE-epsilon4 carrying AD patients than in corresponding control subjects (chi(2) = 3.67 p = 0.055). The ID/AA genotype frequency was lower in AD patients comparing with controls (chi(2) = 4.04, p = 0.044). In AD patients, the G-carrying genotype frequency was significantly higher in APOE-epsilon4 carrier subgroup than in APOE-epsilon4 non-carriers (chi(2) = 7.38, OR = 2.99, 95% CI: 1.33-6.71, p = 0.007). These results indicated that A2M-D allele was probably a weak AD protective factor, and there was a possible interaction of APOE-epsilon4 and A2M-G alleles to increase AD risk in Mainland Han Chinese. (C) 2003 Elsevier B.V. All rights reserved.