Genomics is a relatively new term that describes the study of a person's genes, including interactions of those genes with each other and the person's environment. Genomics involves the scientific study of complex diseases such as heart disease, asthma, diabetes and cancer because they are caused more by a combination of genetic and environmental factors. Genomics is helping to discover why some people get sick from certain infections, environmental factors, and behaviors, while others do not. For example, there are some people who exercise their whole lives, eat a healthy diet, have regular medical checkups, and who die of a heart attack at age 40. There are also people who smoke, never exercise, eat unhealthy foods, and live to be 100. Genomics holds the key to these differences.
Genomics plays an important role in both health and disease. It contributes to 9 of the 10 leading causes of death in the United States (for example, heart disease, cancer, and diabetes). All human beings are 99.9 percent identical in their genetic makeup. Differences in the remaining 0.1% hold important clues about the causes of diseases. Having a better understanding of the interactions between genes and the environment is helping us to find improved methods to advance health and prevent diseases. Genomics is offering new possibilities for therapies and treatment of some diseases, as well as new diagnostic methods. The major tools and methods related to genomics studies are bioinformatics, genetic analysis, measurement of gene expression, and determination of gene function.
Researchers from the University of Colorado Health Sciences Center, along with colleagues from Stanford University, report the results of a large-scale, genome-wide study to investigate gene copy number differences among ten primate species, including humans. The study provides an overview of genes and gene families that have undergone major copy number expansions and contractions in different primate lineages spanning approximately 60 million years of evolutionary time. In the report, the scientists speculate how unique, lineage-specific gene copy number expansions and contractions in humans may underlying traits, such as endurance, higher cognitive functioning, and susceptibility to genetic diseases. Primates first appeared on earth approximately 90 million years ago, and today, about 300 different species of primates exist. "One of the main genomic driving forces in primate evolution is gene duplication," explains Dr. James Sikela, a professor at the University of Colorado. "To our knowledge, this study is the most comprehensive assessment of gene copy number variation across human and non-human primate species so far."
Scripps Genomic Medicine works with Scripps Memorial Hospital La Jolla to conduct genomic studies of women for known variants of breast cancer in order to correlate the presence of variants with diagnosis of the disease. The PINK study, which is funded by the Scripps Research Institute, aims to enroll 3,500 women who are receiving screenings at the Scripps Polster Breast Care Center; these women have had at least five years of breast-imaging records available, and have undergone a DNA analysis. The study is focused on common variants because they are present in large numbers, as much as 20 percent to 30 percent of the population, and they "can have a significant impact on public health," Scripps said.
A group of scientists published their research in Nature in 2007. They found type 2 diabetes mellitus results from the interaction of environmental factors with a combination of genetic variants, most of which were unknown. A systematic search for these variants was recently made possible by the development of high-density arrays that permit the genotyping of hundreds of thousands of polymorphisms. They tested 392,935 single-nucleotide polymorphisms in a French case–control cohort. Markers with the most significant difference in genotype frequencies between cases of type 2 diabetes and controls were fast-tracked for testing in a second cohort. This identified four loci containing variants that confer type 2 diabetes risk, in addition to confirming the known association with the TCF7L2 gene. These loci include a non-synonymous polymorphism in the zinc transporter SLC30A8, which is expressed exclusively in insulin-producing -cells, and two linkage disequilibrium blocks that contain genes potentially involved in -cell development or function (IDE–KIF11–HHEX and EXT2–ALX4). These associations explain a substantial portion of disease risk and constitute proof of principle for the genome-wide approach to the elucidation of complex genetic traits.