Notes
Slide Show
Outline
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Detecting Genetic Association
in Case-Control Studies
Using BGTA Method
  • Hui Wang
  • Department of Statistics, Columbia University


  • This is joint work with professor Shaw-Hwa Lo and Tian Zheng


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OUTLINE
  • Introduction to the background and some methods


  • Motivation of BGTA method and its advantages


  • Implementing BGTA algorithm and some results


  • Further discussion and future work


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Background and Some Methods
    • A lot of new technologies have been
    •    developed in the molecular biology.

    • Current methods and problems in
    • detecting genetic associations, especially
    • the gene interactions in the complex traits.
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Motivation of BGTA method
and its advantages
    • Case-Control studies --- easy sample collection and implementation.
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Primary statistics and terms
used in BGTA algorithm
      • How to denote and index the genotype?
      • A vector is used to denote the haplotype. Each entry of the vector is
      • 0 or 1 to represent the allele status for each marker.


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 The aggregated transmission counts of each genotype
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 Genotype Transmission Disequilibrium  (GTD)
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 Genotype Transmission Disequilibrium  (GTD)
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  Genotype Transmission Association  (GTA)
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  Genotype Transmission Association  (GTA)
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  Genotype Transmission Association  (GTA)
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Genotype Transmission Association  (GTA)
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Properties of GTA under three scenarios
      • The marker being tested M(r) is in transmission disequilibrium (due to true linkage/LD) with the disease while the other markers’ transmissions are independent of the disease status.
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Implementing BGTA and Some Results
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 Simulations and Some Results
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 The frequencies of the markers being selected by BGTA screening
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  Case 2:   Detecting the interactions among disease-linked markers
      • Simulate 15 markers,  4 markers are linked to the disease loci
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Further discussion and future work
      • BGTA algorithm is based on genotypes with diallelic markers. It can also be generalized to more complicated situations.

      • In step 1 and 2, how to compute the variance of GTA and set a more stringent and proper threshold to select suspect markers, and how to create the entire gene network based on the returning marker sets are still on-working.

      • The model of interactions among markers need more considerations.