Relatedness mapping and tracts of relatedness for genome-wide data in the presence of linkage disequilibrium

✍ Scribed by Anders Albrechtsen; Thorfinn Sand Korneliussen; Ida Moltke; Thomas van Overseem Hansen; Finn Cilius Nielsen; Rasmus Nielsen

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 176 KB
• Volume: 33
• Category: Article
• ISSN: 0741-0395
• DOI: 10.1002/gepi.20378

✦ Synopsis

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. Genet. Epidemiol. 2009. © 2008 Wiley‐Liss, Inc.