title: Relatedness mapping and tracts of relatedness for genome-wide data in the presence of linkage disequilibrium.
abstract: Estimates of relatedness have several applications such as the identification of relatives or in identifying disease related genes through identity by descent (IBD) mapping. Here we present a new method for identifying IBD tracts among individuals from genome-wide single nucleotide polymorphisms data. We use a continuous time Markov model where the hidden states are the number of alleles shared IBD between pairs of individuals at a given position. In contrast to previous methods, our method accurately accounts for linkage disequilibrium using pairwise haplotype probabilities. The method provides a map of the local relatedness along the genome. We illustrate the potential of the method for mapping disease genes on a real data set, and show that the method has the potential to map causative disease mutations using only a handful of affected individuals. The new IBD mapping method provides considerable improvement in mapping power in natural populations compared to standard association mapping methods.
authors.affiliation: Department of Biostatistics, Copenhagen University, Copenhagen, Denmark. albrecht@binf.ku.dk
authors.forename: Anders
authors.initials: A
authors.lastname: Albrechtsen
authors.forename: Thorfinn
authors.initials: T
authors.lastname: Sand Korneliussen
authors.forename: Ida
authors.initials: I
authors.lastname: Moltke
authors.forename: Thomas
authors.initials: T
authors.lastname: van Overseem Hansen
authors.forename: Finn Cilius
authors.initials: FC
authors.lastname: Nielsen
authors.forename: Rasmus
authors.initials: R
authors.lastname: Nielsen
mesh_terms: D002874:Chromosome Mapping / Q000379:methods*; D055106:Genome-Wide Association Study; D006801:Humans; D015810:Linkage Disequilibrium; D008390:Markov Chains; D020641:Polymorphism, Single Nucleotide