Abstract:
Genetic mapping has been a very powerful tool for identifying human disease genes. Family-based linkage analysis has lead to mapping several hundreds of human diseases to specific chromosomal regions with nearly 100 genes being identified by positional cloning. However, the success of the linkage analysis has been mainly limited to rare disorders. Numerous efforts of large-scale linkage analysis have been attempted for mapping human common or complex diseases, but only in a very few cases has the linkage analysis been successful in identifying the gene associated with the risk for developing disease such as in Alzheimer’s and Crohn’s diseases. Such a failure is likely due to the pathogenic complexity of human common diseases, which is believed to be influenced by both genetic and non-genetic factors as well as their interaction. Recent progress in genomics, especially the development of high-throughput platform for lage-scale genotyping analysis, has opened new avenues for studying human complex disease. Due to its high power for detection, association analysis has emerged as a much more popular approach for mapping and identifying genes for human complex disease. In this presentation, genetic theories behind gene mapping in human diseases will be discussed briefly. Then, an example will be provided to demonstrate the difficulties and challenges for studying human complex diseases. At last, new strategies for identifying genes for human common diseases, especially those that can take an advantage of the rapid progress in genomics, will be discussed.

Speaker
Dr. Liu is currently a Senior Research Scientist in the population genetics group at the Genome Institute of Singapore (GIS) and an Adjunct Research Fellow in the Centre for Molecular Epidemiology at the National University of Singapore. Besides his academic appointments, Dr. Liu is also a Member of the Central, Sensory & Cellular Nervous System/Mental Health Subcommittee and National Medical Research Council of Singapore. Dr. Liu did his Ph.D. study in quantitative genetics with Prof. Cathy Laurie at the Duke University. After finishing his Ph.D. study, Dr. Liu joined Prof. T. Conrad Gilliam’s laboratory at the Columbia University Genome Center as a Postdoc Research Follow to study the genetic bases of human complex diseases. Before joining GIS in 2002, Dr. Liu was a Research Scientist at the Columbia University Genome Center (CGC) and led the large-scale genotyping analysis effort at CGC. Dr. Liu’s main research interest is to understand the genetic bases of human diseases by using both genetic and genomic approaches.