title: Pairwise Kinship Analysis by the Index of Chromosome Sharing Using High-Density Single Nucleotide Polymorphisms.
abstract: We developed a new approach for pairwise kinship analysis in forensic genetics based on chromosomal sharing between two individuals. Here, we defined "index of chromosome sharing" (ICS) calculated using 174,254 single nucleotide polymorphism (SNP) loci typed by SNP microarray and genetic length of the shared segments from the genotypes of two individuals. To investigate the expected ICS distributions from first- to fifth-degree relatives and unrelated pairs, we used computationally generated genotypes to consider the effect of linkage disequilibrium and recombination. The distributions were used for probabilistic evaluation of the pairwise kinship analysis, such as likelihood ratio (LR) or posterior probability, without allele frequencies and haplotype frequencies. Using our method, all actual sample pairs from volunteers showed significantly high LR values (i.e., ≥ 108); therefore, we can distinguish distant relationships (up to the fifth-degree) from unrelated pairs based on LR. Moreover, we can determine accurate degrees of kinship in up to third-degree relationships with a probability of > 80% using the criterion of posterior probability ≥ 0.90, even if the kinship of the pair is totally unpredictable. This approach greatly improves pairwise kinship analysis of distant relationships, specifically in cases involving identification of disaster victims or missing persons.
authors.affiliation: Department of Forensic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Morimoto
authors.affiliation: Department of Forensic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Manabe
authors.affiliation: Unit of Human Disease Genomics, Center for Genomic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Kawaguchi
authors.affiliation: Department of Forensic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kawai
authors.affiliation: Department of Forensic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Department of Forensic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.|Forensic Science Laboratory, Kyoto Prefectural Police Headquarters, Kyoto, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Hamano
authors.affiliation: Unit of Statistical Genetics, Center for Genomic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Yamada
authors.affiliation: Unit of Human Disease Genomics, Center for Genomic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Matsuda
authors.affiliation: Department of Forensic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Tamaki
mesh_terms: D002877:Chromosomes, Human; D053803:Forensic Genetics; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011336:Probability