Multivariate association between single-nucleotide polymorphisms in Alzgene linkage regions and structural changes in...

Area of Science:

• Neuroimaging
• Genetics
• Alzheimer's Disease Research

Background:

• Alzheimer's disease (AD) heritability is not fully explained by known genetic factors.
• Imaging genetics offers a powerful approach to link genetic variations to brain changes in AD.
• Previous studies have identified linkage regions for AD but require finer genetic resolution.

Purpose of the Study:

• To investigate the association between single-nucleotide polymorphisms (SNPs) in AD linkage regions and the rate of brain structure decline.
• To identify specific SNPs and genes contributing to AD-related neurodegeneration.
• To address challenges in high-dimensional imaging-genetics data analysis.

Main Methods:

• Utilized publicly available data from the Alzheimer's Disease Neuroimaging Initiative (ADNI).
• Applied a weighted RV test for initial SNP association analysis with structural MRI changes in 56 brain regions (632 subjects).
• Employed bootstrap-enhanced sparse canonical correlation analysis for SNP refinement and validation in an independent dataset.

Main Results:

• Identified and refined lists of 1694 and 22 significant SNPs associated with brain structure decline.
• Validated the association of 1694 SNPs with imaging phenotypes in an independent cohort.
• Priority SNPs mapped to genes like GCLC, IDE, and STAMBP1, previously implicated in AD.

Conclusions:

• The identified SNPs, though likely small in effect, offer a valuable resource for understanding AD's missing heritability.
• This imaging-genetics approach successfully navigated high-dimensional data challenges.
• Further investigation of these priority genes may elucidate novel AD mechanisms.