The winner of the 2004 Robillard Prize was announced at the annual meeting of the SSC at the University of Saskatchewan in Saskatoon. The winner was Zeny Feng, for the thesis “Statistical Methods in Affected Sib Pairs Analysis”. The thesis was written at the University of Waterloo under the direction of Professors Mary Thompson and Jiahua Chen. The prize consists of a certificate, a cheque for $400, a one-year subscription to the Canadian Journal of Statistics, and an invitation to submit a paper based on the thesis to that journal. Dr. Feng delivered an invited lecture based on the thesis at the
meeting.

Dr. Feng received her Bachelor’s degree in Statistics from York University in 1999 and her Master’s degree from the University of Waterloo in 2000. She completed her Ph.D. in Biostatistics at the University of Waterloo in 2004. She is currently a postdoctoral fellow in the Department of Epidemiology and Public Health at the Yale University School of Medicine.

Dr. Feng’s thesis concerns the analysis of data on Identical By Descent (IBD) sharing of alleles by sib pairs affected by an inheritable disease. IBD data at one or more markers on relevant chromosomes from a large sample of affected sib pairs allow testing for linkage of the markers to disease genes. At a single marker, a sib pair may share 0, 1 or 2 alleles. Dr. Feng proves the general validity of a “triangle constraint” on the probabilities of each of these three possibilities. The triangle constraint can then be used to increase the power of likelihood ratio tests of linkage between the markers and the disease. Dr. Feng then uses a geometric argument to derive the asymptotic distribution of the constrained likelihood ratio statistic for a single marker and gives approximations to the null distribution of the supremum of this statistic over several markers. Dr. Feng goes on to consider plots of IBD counts against marker position, using the theory of level crossings of a Gaussian process to identify significant peaks in the plot, another tool for finding the location of the disease gene. The committee was impressed by the combination of technical skill, clear writing and careful methodological development in the service of attacking an important problem.

The prize winner was selected by a committee consisting of Professors Rachel Altman (Simon Fraser University – last year’s Robillard winner), Paul Gustafson (University of British Columbia), Richard Lockhart (Simon Fraser University), Edward Susko (Dalhousie University) and Mu Zhu (University of Waterloo). This year ten theses were submitted. As always, the committee was impressed by the high quality of the submissions, the diversity of material and the wealth of interesting theory, methods and applications.

Richard Lockhart, Simon Fraser University, Chair of the Pierre Robillard Committee