Vol. 60, No. 4, 2005
Issue release date: February 2006
Hum Hered 2005;60:206–210
(DOI:10.1159/000090544)
Original Paper
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What Is the Significance of a Significant TDT?

Ewens W.J.a · Spielman R.S.b
aDepartment of Biology and bDepartment of Genetics, University of Pennsylvania, Philadelphia, Pa., USA
email Corresponding Author


 goto top of outline Key Words

  • TDT
  • Linkage
  • Association
  • Haplotype relative risk
  • Hypothesis testing
  • Validity
  • Linkage disequilibrium

 goto top of outline Abstract

This note summarizes the development of the transmission/disequilibrium test (TDT). The initial purpose of the TDT procedure was to test for linkage between a genetic marker and a disease susceptibility locus when an association had been found between the two. An association between disease and marker had sometimes been taken to imply linkage. An association could, however, be due to population stratification even in the absence of linkage. In contrast, the outcome of the TDT is not affected by such stratification. Furthermore, when linkage is not in doubt, the TDT can, in some cases, also provide a test of association between marker and disease. We discuss these various matters in this paper.

Copyright © 2005 S. Karger AG, Basel


 goto top of outline References
  1. Spielman RS, McGinnis RE, Ewens WJ: Transmission test for linkage disequilibrium: The insulin gene region and insulin-dependent diabetes mellitus. Am J Hum Genet 1993;52:506–516.
  2. Nerup J, Platz P, Andersen OO, Christy M, Lyngsoe J, Poulsen JE, Ryder LP, Nielsen LS, Thomsen M, Svejgaard A: HL-A antigens and diabetes mellitus. Lancet 1974;2:864–866.
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    External Resources

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    External Resources

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 goto top of outline Author Contacts

Prof. Warren J. Ewens
Department of Biology, University of Pennsylvania
Philadelphia, PA 19104-6018 (USA)
Tel. +1 215 898 7109, Fax +1 215 898 8780
E-Mail wewens@sas.upenn.edu, spielman@pobox.upenn.edu


 goto top of outline Article Information

Received: August 22, 2005
Accepted: November 7, 2005
Published online: January 2, 2006
Number of Print Pages : 5
Number of Figures : 0, Number of Tables : 2, Number of References : 17


 goto top of outline Publication Details

Human Heredity (International Journal of Human and Medical Genetics)

Vol. 60, No. 4, Year 2005 (Cover Date: February 2006)

Journal Editor: Devoto, M. (Wilmington, Del.)
ISSN: 0001–5652 (print), 1423–0062 (Online)

For additional information: http://www.karger.com/HHE


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