Major allele homozygosity for CD8A (rs3810831) was associated with a higher frequency of affected relatives (p = 0.052), increased severity as characterized by age at diagnosis (p = 0.009), age at first surgery (p = 0.004), and number of surgeries (p = 0.008), whereas TAPBP (rs2282851) was associated increased risk for CRS (odds ratio [OR] = 2.48, p = 0.0076).