Genome-wide association mapping identified a locus on CFA5. (A) The best association was identified by sibTDT analysis (P_genomeTDT = 0.00060), but case-control association was also significant (P_genomeASSOC = 5.2 × 10⁻³) using PLINK (Purcell et al. 2007). (B) Comparison of sibTDT and single SNP association statistics across the CFA5 region.