Abstract
The transmission/disequilibrium test (TDT) is a popular method for detection of the genetic basis of a disease. Investigators planning such studies require computation of sample size and power, allowing for a general genetic model. Here, a rigorous method is presented for obtaining the power approximations of the TDT for samples consisting of families with either a single affected child or affected sib pairs. Power calculations based on simulation show that these approximations are quite precise. By this method, it is also shown that a previously published power approximation of the TDT is erroneous.
Full Text
The Full Text of this article is available as a PDF (235.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bellivier F., Leboyer M., Courtet P., Buresi C., Beaufils B., Samolyk D., Allilaire J. F., Feingold J., Mallet J., Malafosse A. Association between the tryptophan hydroxylase gene and manic-depressive illness. Arch Gen Psychiatry. 1998 Jan;55(1):33–37. doi: 10.1001/archpsyc.55.1.33. [DOI] [PubMed] [Google Scholar]
- Blackwelder W. C., Elston R. C. A comparison of sib-pair linkage tests for disease susceptibility loci. Genet Epidemiol. 1985;2(1):85–97. doi: 10.1002/gepi.1370020109. [DOI] [PubMed] [Google Scholar]
- Camp N. J. Genomewide transmission/disequilibrium testing--consideration of the genotypic relative risks at disease loci. Am J Hum Genet. 1997 Dec;61(6):1424–1430. doi: 10.1086/301648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Risch N., Merikangas K. The future of genetic studies of complex human diseases. Science. 1996 Sep 13;273(5281):1516–1517. doi: 10.1126/science.273.5281.1516. [DOI] [PubMed] [Google Scholar]
- Schaid D. J. Transmission disequilibrium, family controls, and great expectations. Am J Hum Genet. 1998 Oct;63(4):935–941. doi: 10.1086/302077. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spielman R. S., McGinnis R. E., Ewens W. J. Transmission test for linkage disequilibrium: the insulin gene region and insulin-dependent diabetes mellitus (IDDM). Am J Hum Genet. 1993 Mar;52(3):506–516. [PMC free article] [PubMed] [Google Scholar]