Genetic Profiling of Alzheimer's Disease

All subjects were genotyped using the Illumina HumanOmni1-Quad BeadChip. Table 1 summarizes the number of individuals in different categories. After quality control, 2024 samples were retained for the final analysis. Details on the study population characteristics and the quality control parameters applied on the samples and markers can be found elsewhere [17] (link), [18] . Briefly, samples were filtered if they had a missing genotype rate ≥0.02, or with mean X-chromosome heterozygosity ≥0.02 for males or outside the range of 0.25∼0.4 for females. Genetic outliers and those with evidence of relatedness (IBD estimate ≥0.4) or non-European ancestry based on genotype data were also excluded. After filtering, 496 AD+P cases, 639 AD intermediate P, 156 AD−P cases and 958 unaffected controls were retained. Markers were excluded if they had a genotype missing rate of >0.02. Markers were examined to determine if missing depended on case/control status or the genotyping batch.