The Division of Biostatistics at the Department of Preventive Medicine invites you to attend the following seminar.
Date: Monday, May 11th, 2020
Time: 2 P.M.
ZOOM Virtual Room Connection: https://tennessee.zoom.us/j/99322680124.
Presenter: Dr. Zonghui Hu, National Institute of Allergy and Infectious Diseases/NIH
Title: “Assessment of collective genetic impact from twin study: a mixture distribution approach”
Abstract: It is challenging to evaluate the genetic impacts on a biologic feature and separate them from the environmental impacts. We approach this through twin studies by assessing the collective genetic impact defined by the differential correlation in monozygotic twins versus dizygotic twins. Since the underlying order in a twin, determined by latent genetic factors, is unknown, the observed twin data are unordered. Conventional methods for correlation are not appropriate. To handle the missing order, we model twin data by a mixture bivariate distribution and estimate under two likelihood functions: the likelihood over the monozygotic and dizygotic twins separately, and the likelihood over the two twin types combined. Both likelihood estimators are consistent. More importantly, the combined likelihood overcomes the drawback of mixture distribution estimation, namely, the slow convergence. It yields correlation coefficient estimator of root-n consistency and allows effective statistical inference on the collective genetic impact. The method is demonstrated by a twin study on immune traits. This is a joint work with Pengfei Li, Dean Follmann and Jing Qin.
About the speaker:
Zonghui Hu holds a PhD in statistics and MS in mathematics from Texas A & M University. Her research interests include semiparametric modeling, missing data problem, high dimensional data analysis, and vaccine design. She has published over 50 research articles in peer-reviewed and leading statistical journals, including the Journal of American Statistical Association, Biometrika, the Journal of Royal Statistical Society Series, and Biometrics. She has collaborated on medical papers in the New England Journal of Medicine and Lancet. Hu has served on the editorial board of Statistics in Medicine as associate editor since 2015. That same year, Hu received the National Institute of Health Directors Award. She has been working at NIH since 2004.
We look forward to seeing you all among us.
Chi-Yang Chiu, Ph.D.
Assistant Professor of Biostatistics
Department of Preventive Medicine, UTHSC