rs2251101

This study evaluated variants in seven amyloid-beta degrading genes (ACE, ECE1, ECE2, IDE, MME, PLAU, TF) for association with Alzheimer's disease (AD) risk and cognitive phenotypes in older adults. In the GERAD1 cohort (3,333 AD cases, 1,225 controls), a four-SNP ECE1 intragenic haplotype (rs212524/rs212525/rs2282714/rs212531) was significantly associated with increased AD risk (OR=1.61, P=0.00035) in APOE ε4 carriers. In the Lothian Birth Cohort 1936 (LBC1936), a two-SNP ECE1 haplotype (rs2282715/rs3026883) was associated with lower non-verbal reasoning scores (β=-0.19, P=0.00036) in APOE ε4 non-carriers. Meta-analysis of four cognitive cohorts confirmed ECE1 promoter region SNPs associated with non-verbal reasoning in APOE ε4 non-carriers. Functional analysis showed the ECE1 rs213045 (338C>A) variant affected promoter activity in neuroblastoma cell lines, suggesting tissue-specific regulation.

This paper presents a two-stage analysis approach to identify genetic heterogeneity and gene-gene interactions in late-onset Alzheimer disease (LOAD). Using Bayesian Classification clustering followed by multifactor dimensionality reduction (MDR), the authors identified LRRTM3 as a primary stratification gene and found that markers in PLAU, ACE, and CDC2 were associated with LOAD specifically within distinct LRRTM3-defined subgroups, suggesting complex gene-gene interactions in LOAD etiology.