Thursday, November 02, 2000

bookmark: connotea :: del.icio.us ::digg ::furl ::reddit ::yahoo::

New Scientist Beyond the Genome: Land of Opportunity
""You can have all the genes in the world, but what you need is to find the link between them and disease," says Allen Roses, director of genetics at drugs giant Glaxo Wellcome. The roots of diseases like haemophilia, which result from a single faulty gene, are relatively easy to spot by studying family medical histories. But finding the origins of more common killers--heart disease, say, or cancer--is more difficult because in most cases no single gene is to blame. Instead, people inherit labyrinthine patterns of genes which somehow interact to raise the risk of disease. To complicate things further, the risk may only materialise through subtle interplay with the environment, such as breathing polluted air, drinking too much booze or smoking cigarettes.

Despite all these confounding factors, the gene sleuths are pressing ahead, teasing out links between genes and disease by studying real human subjects."

British Medical Journal Single gene disorders or complex traits: lessons from the thalassaemias and other monogenic diseases
"As a result of the revolution in the biological sciences following the development of recombinant DNA technology and the sequencing of most of the human genome, the role of genetics in the pathogenesis of human disease now dominates biomedical research. There is every sign that the rapidly evolving technology of the post genome era will unravel the function of the human genome and explain how the 50 000 to 100 000 genes interact with one another and the environment to make us what we are.

The central question for the medical sciences is the extent to which it will be possible to relate events at the molecular level with the clinical findings or phenotypes of patients with particular diseases. This problem will permeate every aspect of medical research and practice in the future. It will dominate predictive genetics and genetic counselling. It will also be of major importance for clinical decision making as new and novel approaches to the treatment of disease become available, particularly those involving genetic manipulation. Further exploration of the genome may also provide information on some of the common killers of Western society, such as heart disease, stroke, diabetes, and psychiatric disease, leading to a new form of pharmacology in which drugs are tailored to an individual's genetic make up. Even more important, and certainly more complex, will be relating genotype to phenotype. Many of our most important diseases almost certainly reflect varying susceptibility, due to the action of many different genes and a wide variety of environmental factors and to the ill understood biology of ageing."

"Is there any way of guessing the likely levels of complexity that will be encountered as the genetic basis of disease is explored with the new technology?"

redux [07.13.00]
The New York Times Genes May Cause 25% of 3 Major Cancers
[requires 'free' registration]
"Genes may cause more than one-quarter of three major types of cancer, more than previously thought, a group of researchers says.

Scandinavian researchers concluded that genes account for 42 percent of the risk for prostate cancer, 35 percent for colorectal cancer and 27 percent for breast cancer.

The rest of the cases are caused by what people do, such as smoking and diet, or what happens to them, such as on-the-job hazards or viral infections, the researchers said."

"...the conclusion runs contrary to the widespread belief that scientists "will find solutions or cures to all diseases in the genes," Dr. Lichtenstein said. "That won't be the case."

redux [05.26.00]
British Medical Journal Genetic epidemiology
"Research in disease aetiology has shifted towards investigating genetic causes, powered by the human genome project. Successful identification of genes for monogenic disease has led to interest in investigating the genetic component of diseases that are often termed complex, that is, they are known to aggregate in families but do not segregate in a mendelian fashion. Genetic epidemiology has permitted identification of genes affecting people's susceptibility to disease, although progress has been much slower than many people expected. While the role of genetic factors in diseases such as hypertension, asthma, and depression is being intensively studied, family studies and the large geographical and temporal variation in the occurrence of many diseases indicate a major role of the environment. Thus, it is necessary to consider findings about susceptibility genes in the context of a population and evaluate the role of genetic factors in relation to other aetiological factors. This article discusses some approaches used to resolve the genetic architecture of disease and to study the relation of genes to environmental factors in the population. "

redux [10.05.00]
BioMedCentral Simplifying genetic disorders
"Simple genetic diseases, such as cystic fibrosis and thalassaemia are just that — simple. A single gene underlies them. Finding it is like climbing a steep hill — hard work but straightforward. Complex disorders, such as asthma and type 2 diabetes, by contrast, have many components, which makes finding a cause more like scaling Everest — far harder, requiring more specialist equipment and the strong possibility of failure.

In work published in the October issue of Nature Genetics, University of Chicago researchers have cleared a path to studying the genetic foundation of type 2, or non-insulin-dependent diabetes mellitus (NIDDM). In a study of a Mexican-American population and two white populations (Finns and Germans) they have found that small genetic variations, called single-nucleotide polymorphisms (SNPs), in a particular gene tend to occur more often in diabetics than in healthy relatives. Although finding a common genetic variation in family groups affected by simple genetic disorders is implicit, a gene implicated in a population with a complex disease could provide a potential new target for gene therapy. "Variation in this gene is associated with a threefold increased risk in the groups studied," explains lead researcher Graeme Bell. "

"The research does represent a shift in the landscape of genetic diseases. "Studies are not going to be easy," says Bell "but they are not impossible and each locus will present its own challenges." Kruglyak feels the path is clearer, if only because of the 'psychological factor' of showing it can succeed. How important it will be in the overall problem of diabetes, or how often this kind of success will occur in other diseases, will emerge in time. "

redux [08.31.00]
The New England Journal Of Medicine The Triple Helix: Gene, Organism, and Environment
""Like any large construction project in the public domain, sequencing the human genome has been a subject of discussion and controversy. Major issues have been the cost of the project, its scientific merit, and the effects of the knowledge gained on human affairs. The concern about cost subsided as the project proved viable and attracted private funding. That leaves the other two questions: What will we learn from this sequence, and how will it affect our lives? With fame and fortune to be made in the genome business, one can only be skeptical of the wondrous claims made by the project's protagonists. The Triple Helix examines these questions from a critical and biologically informed angle."

"In Lewontin's triple helix, the genes are placed in their natural context, where history and geography shape the nature of organisms and the genes they contain. His differences with the most modern of molecular and cellular biologists are irreconcilable and reflect the ever-widening gulf between biologists who have an affinity for what goes on outside the laboratory and those for whom the differences between individuals and between species represent "an annoyance [to be] ignored whenever possible." In many laboratories, organisms are now studied under conditions in which genetic variation is eliminated and the environment held constant. It is only under these special conditions, where neither variation nor natural selection is tolerated, that the triple helix collapses into the double helix and genes appear to be paramount.""