ability to capture variation attributable to rare variants; however, they lack specificity as they focus on identifying stretches of DNA that either contain or are linked to the gene/genes that underlie a trait. Linkage study findings may lead to gene discovery when followed-up with targeted sequence capture; however, it is important to note that linkage study findings may be specific to the families in the pedigrees utilized. On the other hand, association studies are less powerful, but are more specific because they focus on identifying alleles (i.e., alternative forms of a gene caused by SNPs, copy number variants (CNVs), sequence repeats, etc.) that might be a contributing factor for the behavior/disease or linked to it. Notably, genomewide association studies (GWAS) thus far have utilized array-based platforms that provide good global coverage of the genome and genes within it, but primarily focus on common variants (mainly SNPs with a minor allele frequency > 10%), thereby providing very limited coverage of sequence repeats, structural variants, and rare SNPs that are more likely to be seen with NGS. So far, molecular genetic studies have linked variation across chromosomes 1, 2, 3, 4, 7, and 8 to diagnoses of AD (Foroud et al., 2000;
