Another commonly used approach is to rely on the concept of genome-wide significance. Based on the distribution of LD in the genome for a specific population, there are an “effective” number of independent genomic regions, and thus an effective number of statistical tests that should be corrected for. For European-descent populations, this threshold has been estimated at 7.2e-8 [38]. This reasonable approach should be used with caution, however, as the only scenario where this correction is appropriate is when hypotheses are tested on the genome scale. Candidate gene studies or replication studies with a focused hypothesis do not require correction to this level, as the number of effective, independent statistical tests is much, much lower than what is assumed for genome-wide significance.
