QTDT Tests

Parameters | Genetics | QTDT Tests

QTDT Tests

Use this feature to specify the type of quantitative transmission disequilibrium test to be performed.

Available tests are described in the following table:

Test

Definition

O-QTDT

This test (also known as Orthogonal QTDT) regresses the quantitative trait on deviates from the expected genotype conditional on the expected genotype (Abecasis et al., 2000). Both regressors, the expected genotype and deviates, are treated as quantitative. The IBD data set can be used to include all pedigree members in the analysis. Otherwise, founders are not included in the regression and the analysis is valid only for nuclear families with 1 offspring.

TDTq5

This option tests for association by regressing the quantitative trait on offspring genotypes, conditional on the parental mating type class (Allison, 1997).

Tqps

This option tests for association using a score statistic that can analyze parent-offspring trios along with sibships of any size (Monks and Kaplan, 2000).

Sib-QTDT

This test uses a mixed model to test the fixed genotypic class on the quantitative trait by conditioning on the random effects sibship class (unique for each sibship) and sibship class by genotypic class (Allison et al., 1999).

To Specify One or More Tests:

Left-click on the desired test.

Press and hold Ctrl to select more than one test.

Test	Definition
O-QTDT	This test (also known as Orthogonal QTDT) regresses the quantitative trait on deviates from the expected genotype conditional on the expected genotype (Abecasis et al., 2000). Both regressors, the expected genotype and deviates, are treated as quantitative. The IBD data set can be used to include all pedigree members in the analysis. Otherwise, founders are not included in the regression and the analysis is valid only for nuclear families with 1 offspring.
TDTq5	This option tests for association by regressing the quantitative trait on offspring genotypes, conditional on the parental mating type class (Allison, 1997).
Tqps	This option tests for association using a score statistic that can analyze parent-offspring trios along with sibships of any size (Monks and Kaplan, 2000).
Sib-QTDT	This test uses a mixed model to test the fixed genotypic class on the quantitative trait by conditioning on the random effects sibship class (unique for each sibship) and sibship class by genotypic class (Allison et al., 1999).