Skip to main content
. 2018 Oct 17;97(1):35–42. doi: 10.1093/jas/sky407

Table 3.

Case study of available information in the pedigree verification and discovery report for an individual animal born in 2014

Relationship type Information captured in the pedigree verification and discovery report and its interpretation
Progeny There are 20 progeny, 1 of which is genotyped with a genomic relationship coefficient of 0.57—which is above the minimum animal–parent threshold of 0.41
Parents None genotyped, but from paternal half sibling information there is reasonable confidence that the reported sire is correct
Paternal half siblings There are 61 paternal half siblings with genomic relationship coefficients ranging from 0.26 to 0.37, all these half siblings are above the minimum threshold of 0.17, supporting that they truly are half siblings. From this information we can then be reasonably confident that the reported sire is correct, even though we do not have the sire’s genotype available to test
Grandparents Both paternal and maternal grandsires are genotyped with genomic relationship coefficients of 0.34 and 0.05, respectively. The lower than 0.17 threshold suggests that the reported maternal grandsire is not the true grandsire. This could be that the sire of the dam is incorrect, or that the dam has been incorrectly recorded
Great grandparents There are 4 in total genotyped. On the paternal side, both parents of the paternal grandsire are genotyped with genomic relationship coefficients of 0.18 and 0.23 for the great grand sire and great grand dam, respectively
On the maternal side, both great grand sires are genotyped and have genomic relationship coefficients of 0.07 and 0.06, both of which is lower than the threshold of 0.07 suggesting they may not be true great grandparents. This suggests that both the sire and dam of the animals dam are incorrect, or that the dam has been incorrectly reported
Great great grandparents There were 2 genotyped. On the paternal side, a great great grand sire had a genomic relationship coefficient of 0.15, and on the maternal sire, the great great grand sire genomic relationship coefficient = 0.11. Both of these animals have values above the threshold of 0.05 suggesting that these may be the true relationships. However, at this distant relationship it is also possible that they are not related since unrelated animals have been shown to have average genomic relationships of 0.09
Half aunts/ uncles There were 56 genotyped aunts/uncles based on the pedigree. When tested, there were 45 with genomic relationship coefficients ranging from 0.125 to 0.32, and above the threshold of 0.125 (half aunt/uncle) and 11 which have genomic relationship coefficients of 0.04 to 0.08 and thus unlikely to be an aunt/uncle. A high level of failures here is expected when a grandparent has been incorrectly recorded
Half niece/ nephews There were 11 genotyped niece/nephews based on the pedigree. When tested, there were 10 with genomic relationship coefficients ranging from 0.16 to 0.26, and above the threshold of 0.125 (half niece/nephews) and 1 which has a genomic relationship coefficient of 0.09 and thus unlikely to be a niece/nephews. A high level of failures here is expected when a parent has been incorrectly recorded
Potential close relatives There were 36 reported with genomic relationship values of 0.17 and higher, suggesting they are closer relatives. The top 4 animals in the list and the outcome of investigation is listed:
1) genomic relationship coefficient =0.40—a female born in 1998. Given the age range and genetic relationship it is possible that she is the dam, but more likely the grand-dam of animal;
2) genomic relationship coefficient =0.31—a paternal sibling that was incorrectly recorded in the pedigree;
3) genomic relationship coefficient =0.30—a paternal sibling that was incorrectly recorded in the pedigree;
4) genomic relationship coefficient =0.29—a male born in 2001. Given the age range and genetic relationship it is possible that he is the grand-sire of animal
After discussion with the breeder it was identified that matings between animals 1 and 4 on the list did occur and he supplied some candidate dams to test and it was confirmed that the pedigree recorded for the dam was incorrect, and after DNA verification was corrected to be the correct dam, which was a daughter of animals 1 and 4 in the above list