Although GWAS has greater power to detect small effects on phenotype of common variants and copy number variations (CNVs), an adequately powered linkage study design has the advantage of detecting diverse genetic effects that segregate in families, including common variants, multiple rare variants within one locus, and heritable CNVs. With the growing evidence for the role of rare variants and CNVs in psychiatry disorders (60, 61), the consensus regions discovered by linkage studies may serve as a useful complement to the emerging GWAS approach in reconstructing the genetic architecture of psychiatry disorders, especially in pinpointing the causal rare variants that cannot be captured by common tag SNPs in the GWAS design. In conclusion, the current meta-analysis including 15 genome scans of smoking behavior has identified many regions showing evidence of linkage with smoking behavior. Known and novel candidate genes map to the highly ranked regions are of particular interest. Therefore, the regions identified in the current study deserve close attention and will be helpful for candidate gene identification or target resequencing studies in the future.
