TITLE: Familial aggregation of multivariate traits: testing and variable selection

SPEAKER: Professor Yixin Fang

ABSTRACT:

In genetic epidemiology, the first and foremost task is testing for familial aggregation; if no familial aggregation is found, it is unnecessary to conduct further genetic analysis. For multivariate traits, we propose a test statistic, which is actually the leading principal component of heritability. The p-value can be obtained by a permutation procedure or a theorem of Johnstone and Forrester (2004). Furthermore, if the test is significant, it is desired to get rid of those redundant traits to avoid overfitting. To this aim, a cross-validation approach and its approximation are proposed. The talk concludes with some discussion on testing for familial aggregation of functional traits and an application to the cholesterol data from Framingham Heart Study.