RT Journal Article SR Electronic T1 GCA: An R package for genetic connectedness analysis using pedigree and genomic data JF bioRxiv FD Cold Spring Harbor Laboratory SP 696419 DO 10.1101/696419 A1 Yu, Haipeng A1 Morota, Gota YR 2019 UL http://biorxiv.org/content/early/2019/07/09/696419.1.abstract AB Background: Genetic connectedness is a critical component of genetic evaluation as it assesses the comparability of predicted genetic values across management units. Genetic connectedness also plays an essential role in quantifying the linkage between reference and validation sets in whole-genome prediction. Despite its importance, there is no user-friendly software tool available to calculate connectedness statistics. Results: We developed the GCA R package to perform genetic connectedness analysis for pedigree and genomic data. The software implements a large collection of various connectedness statistics as a function of prediction error variance or variance of unit effect estimates. The GCA R package is available at GitHub and the source code is provided as open source. Conclusion: The GCA R package allows users to easily assess the connectedness of their data. It is also useful to determine the potential risk of comparing predicted genetic values of individuals across units or measure the connectedness level between training and testing sets in genomic prediction.