1. Department of Computer Science, Northwestern Polytechnical University, Xi’an, Shaanxi, China
2. Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA
3. Department of Human Genetics, University of Chicago, Chicago, IL, USA
4. Department of Medicine, University of Chicago, Chicago, IL, USA
5. Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA