Figure: The Basset Hound. The background pedigree chart shows carriers of a particular disease or genetic trait. Solid black symbols indicate affected individuals and half black symbols represent unaffected carriers. “PedKin” is the software developed for efficient computation of the kinship coefficients, indicating the genetic similarity between pairs of individuals, given a pedigree of individuals and individuals of interest. Image credit:

Are mixed breed dogs healthier than purebreds?

The motivation – When breeding pedigree animals such as dogs, cats, horses, cows or endangered species, it is essential to prevent inbreeding in order to foster genetic diversity. This genetic diversity is important because it prevents the rise of recessive single-gene (Mendelian) diseases in the population as a whole.  The kinship coefficient is a measure of genetic relatedness between a pair of individuals; it can be used to prohibit inbreeding and, in the case of humans, inbred marriages. Therefore, computing kinship coefficients is fundamental to understanding breeding relationships and human genealogies.

The discovery – Simon Fraser University’s Dr. Liangliang Wang and coauthors developed the fastest known algorithms for computing the kinship coefficient of a set of individuals with a known pedigree; these algorithms are especially useful for computations involving large pedigrees. The newly developed algorithms outperform existing methods. Of particular interest, these algorithms consider the possibility that the founders (individuals who have no parents specified) of the known pedigree may themselves be inbred and compute the appropriate inbreeding-adjusted kinship coefficients; previously, this complex problem had not been addressed in the literature. The authors’ kinship coefficient study resulted in the development of the open source code PedKin, which they provided to implement their algorithms.

Its significance – This method is the fastest known algorithm for computing the kinship coefficients. One can either compute exact coefficients or estimate the coefficients. In addition, this is the only algorithm that considers the inbreeding coefficients of the founders.  The software PedKin, developed by the team, has become an important tool to efficiently compute kinship coefficients for biologists and researchers in the field of genetics. Now the question of whether mixed breed dogs are healthier than purebreds can be studied on a large scale.

Read the paper“Efficient computation of the kinship coefficients ” by Kirkpatrick, B; Ge, SF; Wang, LL. Bioinformatics 35(6): 1002-1008 (2019). DOI: 10.1093/bioinformatics/bty725.

Website article compiled by Jacqueline Watson with Theresa Kitos