A Chromosome-based method to infer IBD scores for missing and ambiguous markers

Authors

  • Dr. Chi Gu,

    Corresponding author
    1. Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
    • Washington University Medical School, Department of Psychiatry (Box 8134), 4940 Children's Place, St. Louis, MO 63110

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  • Brian K. Suarez,

    1. Department of Genetics, Washington University School of Medicine, St. Louis, Missouri
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  • Theodore Reich,

    1. Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
    2. Department of Genetics, Washington University School of Medicine, St. Louis, Missouri
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  • Alexandre A. Todorov

    1. Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri
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Abstract

We propose a probability model to impute missing identical-by-descent (IBD) vectors for linkage analysis, when adjacent marker loci are typed and interference is estimable. A chromosome-based IBD distribution, conditioned on available marker data, is computed using a fast algorithm to estimate the joint probability of genes IBD at several equally spaced linked loci. Weighted IBD vectors are then used in various test statistics for linkage analysis. As an example, we analyzed the 18 affected sib pairs in the GAW9 Problem 1 data set using Risch's lod-score test. © 1995 Wiley-Liss, Inc.

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