New DNA research clearly shows that health disadvantages of childhood could remain for life. Later improvement in living conditions might not be of much help, it seems.
New DNA research clearly shows that health disadvantages of childhood could remain for life. Later improvement in living conditions might not be of much help, it seems. The team, based at McGill University in Montreal, University of British Columbia in Vancouver and the UCL Institute of Child Health in London looked for gene methylation associated with social and economic factors in early life. They found clear differences in gene methylation between those brought up in families with very high and very low standards of living. More than twice as many methylation differences were associated with the combined effect of the wealth, housing conditions and occupation of parents (that is, early upbringing) than were associated with the current socio-economic circumstances in adulthood. (1252 differences as opposed to 545).
The findings are published online today in the International Journal of Epidemiology. The scientists decided to look at DNA methylation, a so-called epigenetic modification that is linked to enduring changes in gene activity and hence potential health risks. (Broadly, methylation of a gene at a significant point in the DNA reduces the activity of the gene.)
Researchers focussed on 40 UK participants in an ongoing study that has documented many aspects of the lives of over 10,000 people born in March 1958 from birth onwards.
The researchers studied DNA that was prepared from blood samples taken when the participants were 45 years old. They chose people who experienced either very high or very low standards of living as children or adults, to study any differences in DNA methylation that might exist between people with very different living conditions. The analysis measured DNA methylation differences between socio-economic groups at the control regions of over 20,000 genes.
“This is the first time we’ve been able to make the link between the economics of early life and the biochemistry of DNA,” says Moshe Szyf, McGill professor of Pharmacology.
“If we think of the genome as sentences, your DNA, or letters are what is inherited from your father and mother. The DNA methylation is like the punctuation marks that determine how the letters should be combined into sentences and paragraphs that are read differently in the different organs of the body the heart, the brain, and so on,” Szyf explains. ”What we’ve learned is that these punctuation marks are attentive to signals that come from the environment, and that they take cues from living conditions in childhood. Essentially, they act as a mechanism, we believe, for adapting the DNA to the fast changing world.”
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The methylation profiles associated with childhood family living conditions were clustered together in large stretches of DNA, which suggests that a well-defined epigenetic pattern is linked to early socio-economic environment. “The adult diseases already known to be associated with early life disadvantage include coronary heart disease, type 2 diabetes and respiratory disorders,” said author, Chris Power, Professor of Epidemiology and Public Health at the UCL Institute of Child Health, “so it is hoped that future research will define which network of genes showing methylation differences are in turn associated with particular diseases.”
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Source-Medindia