The association of the Chromosome 4 region in the FHS cohort was genome-wide significant for the FEV1/FVC ratio and was also associated with COPD. This association was subsequently replicated in the Family Heart Study population. Though the HHIP locus association in our study did not reach genome-wide significance, the additional evidence from the FHS and Family Heart Study underscore the importance of this locus on COPD susceptibility.
