Study Finds How Genes That Cause Illness Work Gina Kolata Jan 20 2013 New York Times http://www.nytimes.com/2013/01/21/health/study-pinpoints-what-activates-disease-causing-genes.html?nl=todaysheadlines&emc=edit_th_20130121&_r=0
[Excerpted] In the new study, researchers compared 354 newly diagnosed rheumatoid arthritis patients and 337 healthy people who served as controls. The goal was to review both groups’ white blood cells, examining their DNA for chemical tags — methyl groups — that could attach themselves to genes and turn them on or off.
It was much more complicated than just studying genes themselves.
Researchers know a gene will remain stable, but the chemical tags that
turn the genes on and off are not so reliable. Their presence can be
affected by the environment or medications or even the activity of
other, distant genes. They can be a consequence of a disease or set off a
disease....
Majia here: In this particular study the researchers found four chemical tags, out of hundreds, that seemed related to rheumatoid arthritis. These four tags were located in a group of genes controlling immune response. The tags were located in a gene known as C6orf10. That gene is not understood well.
Its important to emphasize that the operations of these chemical tags are subject to disruption. As the article states: "Their presence can be affected by the environment or medications or even the activity of other, distant genes. They can be a consequence of a disease or set off a disease...."
Nova provides a description of epigenetics:
[Excerpted] Once nurture seemed clearly distinct from nature. Now it appears that our diets and lifestyles can change the expression of our genes. How? By influencing a network of chemical switches within our cells collectively known as the epigenome. This new understanding may lead us to potent new medical therapies. http://www.pbs.org/wgbh/nova/body/epigenetics.html
Majia here: Its my belief that we will find the answers to autism and a variety of other conditions, especially immune and brain diseases - allergies, asthma, and parkinsons - in epigenetic processes.
This is exciting reseach and it illustrates the fundamental openness of biological systems to environmental inputs.
Failure to recognize this openness will be our biological undoing because we are rapidly changing our environment by creating and disseminating caustic chemicals and genotoxic radiation.
This is exciting reseach and it illustrates the fundamental openness of biological systems to environmental inputs.
Failure to recognize this openness will be our biological undoing because we are rapidly changing our environment by creating and disseminating caustic chemicals and genotoxic radiation.
Here is the study and its abstract:
Epigenome-wide
association data implicate DNA methylation as an intermediary of genetic risk
in rheumatoid arthritis by Yun Liu et al Nature
Biotechnology (2013) http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.2487.html
[Abstract] Epigenetic mechanisms integrate genetic and environmental causes of
disease, but comprehensive genome-wide analyses of epigenetic modifications
have not yet demonstrated robust association with common diseases. Using
Illumina HumanMethylation450 arrays on 354 anti-citrullinated protein
antibody–associated rheumatoid arthritis cases and 337 controls, we identified
two clusters within the major histocompatibility complex (MHC) region whose
differential methylation potentially mediates genetic risk for rheumatoid
arthritis. To reduce confounding factors that have hampered previous
epigenome-wide studies, we corrected for cellular heterogeneity by estimating
and adjusting for cell-type proportions in our blood-derived DNA samples and
used mediation analysis to filter out associations likely to be a consequence
of disease. Four CpGs also showed an association between genotype and variance
of methylation. The associations for both clusters replicated at least one CpG
(P < 0.01), with the rest showing suggestive association, in monocyte
cell fractions in an independent cohort of 12 cases and 12 controls. Thus, DNA
methylation is a potential mediator of genetic risk.
Susceptibility to cancer is affected by genetic and epigenetic features, and is enhanced by ionizing radiation:
ReplyDeletehttp://link.springer.com/article/10.1007%2Fs00259-004-1731-6
The damage to chromosomes and the genetic structure increases in each generation. Every generation is more susceptible to the effects of radiation than the previous one. Lower levels of radiation cause cancer and other diseases over time. The studies about radiation exposure and cancer become obsolete and invalid... the atomic bomb study is the most obsolete one.
Excellent find on the issue of increasing susceptibility across generations. I can use that cite. Thank you!!!
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