Kim’s public health blog

ScienceDaily (June 7, 2009) — New research indicates that natural selection may shape the human genome much more slowly than previously thought. Other factors — the movements of humans within and among continents, the expansions and contractions of populations, and the vagaries of genetic chance – have heavily influenced the distribution of genetic variations in populations around the world. Comment: Is there any chance that these studies can lead to a change in racial animositt? We are all mongrels.

From Today’s BMJ [BMJ 2009;338:b873] Michael Oliver, professor emeritus of cardiology, University of Edinburgh says primary prevention among young and middle aged adults should be encouraged and supported. But should this apply equally to fit elderly people? Nowadays few elderly people are allowed to enjoy being healthy. A bureaucratic demand for documentation can lead to overdiagnosis, overtreatment, and unnecessary anxiety. Preventive action may be irrelevant and even harmful in elderly people. More than 30 years ago, in his book Medical Nemesis, Ivan Illich called this trend “the medicalisation of health.”

Parents of children with genetic conditions may avoid the need to choose whether to undergo pre-natal testing or to abort future pregnancies by simply avoiding subsequent pregnancy altogether, a study has found. Parents are ‘choosing not to choose’, researcher Dr Susan Kelly, who is based at the Egenis research centre at University of Exeter,the suggests, in a ‘reflection of deep-seated ambivalence’ about the options and the limitations of new reproductive technologies. According to ‘Choosing not to choose: reproductive responses of parents of children with genetic conditions or impairments’ published in the journal Sociology of Health and Illness, more than two-thirds of parents in the USA-based study chose not to have any more children rather than accepting tests to identify or avoid the birth of an affected child. Of the parents who did have further children, a majority chose not to make use of prenatal screening or testing.

Maybe the first effective application of personalized treatment rather than using a single population standard. A set of 50 genes can be used to reliably identify the four known types of breast cancer, according to research conducted at Washington University School of Medicine in St. Louis and collaborating institutions. Using this 50-gene set, oncologists can potentially predict the most effective therapy for each breast tumor type and thereby personalize cancer treatment for all patients. “Unlike a widely used genomic test that applies only to lymph-node negative, estrogen-receptor positive breast cancer, this new genomic test is broadly applicable for all women diagnosed with breast cancer,” says breast cancer specialist Matthew Ellis, M.D., Ph.D., a member of the Siteman Cancer Center at Barnes-Jewish Hospital and Washington University.

ScienceDaily— We may be a long way off from using genetics to reliably gauge our risks for specific diseases, say researchers at the University of Pittsburgh Graduate School of Public Health in a study published on Feb. 5 in the online journal PLoS Genetics. Yet, many companies currently offer personalized genetic testing for diseases like cancer, heart disease and diabetes, and tout the ability of DNA testing to predict future health risks. The rapid discovery of new genetic risk factors is giving us vitally important insights into human health, but a strong association between these factors and disease risk may not reliably predict which health issues a specific individual will face in the future,” said Daniel E. Weeks, Ph.D., senior author and professor of human genetics and biostatistics at the University of Pittsburgh Graduate School of Public Health. “Our study indicates that even though we can paint a picture of our genetic makeup with current tests, this may not be enough to help us understand our individual risk for disease.” Comment: The message is Be cautious, the hucksters are at it again.

College students often spend their free time thinking about beer, but a group of Rice University students are taking it to the next level. They’re using genetic engineering to create beer that contains resveratrol, a chemical in wine that’s been shown to reduce cancer and heart disease in lab animals.

Reported in the July 8 issue of the Proceedings of the National Academy of Sciences, Neuroscientists at MIT’s Picower Institute for Learning and Memory found that a previously unsuspected set of genes links nature and nurture during a crucial period of brain development.
Researchers believe autism spectrum disorders are tied to brain changes that occur during critical periods of development. Different but overlapping critical periods are thought to exist for various cognitive functions affected in autism, such as language and social behaviors. “Autism is a strongly genetic disorder: genes set up risk factors but by themselves simply make proteins,” Sur said. “Genes work together with other influences. In the case of autism, these influences are unknown but could be molecules made by other genes or chemicals from the environment.” Comment: Despite research which ha repeatedly shown lack of a link between immunization and autism, parents of such children are not yet ready to accept genes as causative of autism, and prefer to blame vaccines.