The transmission disequilibrium test and imprinting effects test based on case-parent pairs.
The transmission disequilibrium test (TDT) based on case-parents trios is a powerful tool in linkage analysis and association studies. When only one parent is available, the 1-TDT is applicable in the absence of imprinting. In the presence of imprinting, a statistic is proposed, based on case-mother pairs and case-father pairs to test for linkage when association is present as well as to test for association when linkage is present. The recombination fractions are allowed to be sex-specific in this test statistic. Meanwhile, a statistic based on case-parent pairs is proposed to test for imprinting. Both test statistics can be extended to include families with more than one affected offspring. A number of simulation studies are conducted to investigate the validity of the proposed tests. The effects of different ratios of the numbers of case-mother pairs and case-father pairs on the powers of the proposed tests are studied through simulation. The results show that the optimal ratio is 1:1. How to combine case-parents, case-mother pairs, and case-father pairs jointly in testing for linkage, association, and imprinting is addressed.
Hu
Yue-Qing
YQ
Department of Statistics and Actuarial Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Zhou
Ji-Yuan
JY
Sun
Fengzhu
F
Fung
Wing K
WK
D003198:Computer Simulation; D005220:Fathers; D005260:Female; D005821:Genetic Techniques; D018392:Genomic Imprinting; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008957:Models, Genetic; D009035:Mothers; D010290:Parents