title: Parente2: a fast and accurate method for detecting identity by descent.
abstract: Identity-by-descent (IBD) inference is the problem of establishing a genetic connection between two individuals through a genomic segment that is inherited by both individuals from a recent common ancestor. IBD inference is an important preceding step in a variety of population genomic studies, ranging from demographic studies to linking genomic variation with phenotype and disease. The problem of accurate IBD detection has become increasingly challenging with the availability of large collections of human genotypes and genomes: Given a cohort's size, a quadratic number of pairwise genome comparisons must be performed. Therefore, computation time and the false discovery rate can also scale quadratically. To enable accurate and efficient large-scale IBD detection, we present Parente2, a novel method for detecting IBD segments. Parente2 is based on an embedded log-likelihood ratio and uses a model that accounts for linkage disequilibrium by explicitly modeling haplotype frequencies. Parente2 operates directly on genotype data without the need to phase data prior to IBD inference. We evaluate Parente2's performance through extensive simulations using real data, and we show that it provides substantially higher accuracy compared to previous state-of-the-art methods while maintaining high computational efficiency.
authors.affiliation: Biomedical Informatics Program.
authors.forename: Jesse M
authors.initials: JM
authors.lastname: Rodriguez
authors.affiliation: Department of Computer Science, Stanford University, Stanford, California 94305, USA.
authors.forename: Sivan
authors.initials: S
authors.lastname: Bercovici
authors.affiliation: Department of Computer Science, Stanford University, Stanford, California 94305, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Computer Science, Stanford University, Stanford, California 94305, USA.
authors.forename: Roy
authors.initials: R
authors.lastname: Frostig
authors.affiliation: Department of Computer Science, Stanford University, Stanford, California 94305, USA.
authors.forename: Serafim
authors.initials: S
authors.lastname: Batzoglou
mesh_terms: D000465:Algorithms; D066264:Datasets as Topic; D008040:Genetic Linkage; D005820:Genetic Testing / Q000379:methods* / Q000592:standards; D023281:Genomics / Q000379:methods* / Q000592:standards; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008957:Models, Genetic; D015233:Models, Statistical; D010375:Pedigree; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity