Validation and optimization of Alzheimer's Disease phenotypes prediction using machine learning enabled polygenic risk models

Analyzing postmortem phenotype and genomics data from ~1100 human brain samples with machine learning, Vivid Genomics, Inc., has developed prototype genetic biomarker assays that predict the presence of amyloid plaques, Lewy body pathology, cerebral amyloid angiopathy, and rate of cognitive decline. The objective is to increase subject numbers with similar data available through NIAGADS and NACC, along with datasets from several individual academic centers, to further optimize and validate our assays for neurodegenerative/cerebrovascular lesion types including tau, TDP-43, hippocampal sclerosis and microinfarcts, and for predicting rate of cognitive decline. NIAGADS datasets requested are NG00067 (including the newly released data which is new version 9 for dataset NG00067), NG00119, NG00117 and NG00127; data use limitations from these do not exclude our proposed usage. We are targeting >3000 subjects in total to be used for the validation of our models. We will focus on SNP selection and test the effects of different analysis strategies: 1) changing SNP p-value cutoffs 2) using LD-filtered representative SNPs with full genome coverage 3) testing the value of stratifying by APOE genotype 4) determining if it is better to add other covariates including age and sex. A fraction of the genetic data (~30%) will be withheld for validation. Optimization is defined as an area under the curve (AUC) of 80% and positive predictive value (PPV) of 80%, as well as R2 >0.75 for all assays. Values within 10% of this will be considered a successful validation. Through these assays, this project will benefit those suffering from Alzheimer’s disease and other neurodegenerative disorders by increasing clinical trial efficiency through more precise subject selection and/or stratification.

Vivid Genomics is dedicated to developing genetic tests, typically done from DNA obtained from blood, that will predict, for any given older person, the likelihood that they have, or might develop when they become old, the characteristic brain changes of Alzheimer’s disease as well as other brain changes that affect thinking in older people. These changes include amyloid or senile plaques, tangles or tau, amyloid angiopathy, Lewy bodies, TDP-43 pathology, hippocampal sclerosis and brain infarcts (strokes). The objective of this study is to improve upon initial tests developed by Vivid, and to also develop genetic tests to predict the rate at which older people’s thinking ability decreases over time. To do this, Vivid Genomics requests human subject DNA analysis data stored at NIAGADS. Through these new genetic tests, Vivid hopes to benefit those suffering from Alzheimer’s disease and other brain diseases of aging by allowing better selection of subjects for clinical trials of these diseases, which would increase the chances of clinical trials finding useful new treatments.