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Unformatted text preview: e environmental influences has an overwhelming effect on illness risk-- otherwise, researchers would have probably noticed it by now-- so epidemiologists will need to study large numbers of people to tease out all the small contributions. By taking both genetic and environmental factors into account, this method may be able to determine whether a person is at high risk for acquiring a particular brain disorder. High-risk patients could then receive close scrutiny in follow-up observations, and if symptoms of the disorder appear, doctors would be able to begin treatment at the earliest stages of the illness. Genes are not equivalent to fate. Our brains are the PRODUCTS OF GENES, ENVIRONMENT AND CHANCE operating over a lifetime.
that are necessary and sufficient to cause either schizophrenia or autism. Instead these illnesses may arise by several pathways. This situation, called genetic complexity, seems to apply to bipolar disorder and depression as well. Each of these disorders may actually represent a group of closely related mental illnesses that share key aspects of abnormal physiology and symptoms but may differ in details large and small, including severity and responsiveness to treatment. What are the implications for diagnosis? Imagine that variations in 10 distinct genes can boost the risk of developing a mental illness but that none of the genetic variations by itself is either necessary or sufficient to bring on the disorder (this is close to a current model for autism). Different combinations of the variant genes may confer risks of similar but not identical forms of the illness. To correlate all the possible genetic combinations with all the clinical outcomes would be an immensely complex task. But the tools for such an undertaking are already available. Thanks to technologies developed for the Human Genome Project, scientists can rapidly determine what variations are present in a person's DNA. Using gene chips-- small glass slides holding For patients already showing symptoms of a disorder, their genetic information would be quite useful in narrowing down the diagnostic possibilities. And as researchers learn how genetic variations can affect responses to drugs, knowing a patient's genomic profile could help a physician choose the best treatment. But there is a downside to this medical advance: in a society where people can carry their DNA sequences on a memory chip, policymakers would have to grapple with the question of who should have access to this data. Even though a genetic sequence by itself cannot definitively predict whether a person will descend into depression or psychosis, one can readily imagine how employers, educational institutions and insurance companies might use or misuse this information. Society at large will have to...
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This note was uploaded on 05/02/2010 for the course PSY 320 taught by Professor Na during the Spring '10 term at Suffolk.
- Spring '10