Department of Computer Science, Northwestern Polytechnical University, Xian, Shaanxi, China.|Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA.|Department of Human Genetics, University of Chicago, Chicago, IL, USA.|Department of Human Genetics, University of Chicago, Chicago, IL, USA.|Department of Human Genetics, University of Chicago, Chicago, IL, USA.|Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA.