Fig. 2

Distichiasis Pedigree Investigation. Represented is the most informative portion of the pedigree. Specifically, pedigree analysis showed that five of 21 affected horses shared a common ancestor within a single generation (S3, indicated with an orange border), which was not related to any of the controls. Two additional affected horses could be traced to the sire of S3 (GS3, indicated with a yellow border). Taken together, these findings support a genetic basis for this disease. Cases are denoted with red shading. Disease states of ancestors are unknown and denoted with white shading. One unaffected individual is denoted with blue shading