title: The architecture of long-range haplotypes shared within and across populations.
abstract: Homologous long segments along the genomes of close or remote relatives that are identical by descent (IBD) from a common ancestor provide clues for recent events in human genetics. We set out to extensively map such IBD segments in large cohorts and investigate their distribution within and across different populations. We report analysis of several data sets, demonstrating that IBD is more common than expected by naïve models of population genetics. We show that the frequency of IBD pairs is population dependent and can be used to cluster individuals into populations, detect a homogeneous subpopulation within a larger cohort, and infer bottleneck events in such a subpopulation. Specifically, we show that Ashkenazi Jewish individuals are all connected through transitive remote family ties evident by sharing of 50 cM IBD to a publicly available data set of less than 400 individuals. We further expose regions where long-range haplotypes are shared significantly more often than elsewhere in the genome, observed across multiple populations, and enriched for common long structural variation. These are inconsistent with recent relatedness and suggest ancient common ancestry, with limited recombination between haplotypes.
authors: Department of Computer Science, Columbia University, New York, New York, USA.
authors: Alexander
authors: A
authors: Gusev
authors: Pier Francesco
authors: PF
authors: Palamara
authors: Gregory
authors: G
authors: Aponte
authors: Zhong
authors: Z
authors: Zhuang
authors: Ariel
authors: A
authors: Darvasi
authors: Peter
authors: P
authors: Gregersen
authors: Itsik
authors: I
authors: Pe'er
mesh_terms: D002874:Chromosome Mapping; D019143:Evolution, Molecular; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population / Q000379:methods*; D015894:Genome, Human; D006239:Haplotypes; D006801:Humans; D007585:Jews / Q000235:genetics; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide