Current evidence suggests that copy number variants (CNVs) and rare single-nucleotide polymorphisms (SNPs) might be implicated in the risk for many complex diseases [Walsh et al., 2008; Johansen et al., 2010]. Genomewide association studies are unable to capture most of these rare genetic variants. An adequately powered linkage study design has the advantage of detecting diverse inherited genetic effects that segregate in families, including common variants, rare variants and CNVs. Since the current cost of conducting a large-scale whole genome sequencing study is still high, genetic linkage approaches remain valuable and informative to identify candidate regions for targeted resequencing studies.
