The pleiotropic structure of the genotype–phenotype map: the evolvability of complex organisms. Günter P. Wagner & Jianzhi Zhang,p204 | doi:10.1038/nrg2949

Abundant Pleiotropy in Human Complex Diseases and Traits,The American Journal of Human Genetics, Volume 89, Issue 5, 607-618, 11 November 2011 doi:10.1016/j.ajhg.2011.10.004 アプローチとか(こちら)