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Disadvantage “gets under the skin” and alters genes

Poverty and social disadvantage “get under the skin” and alter genes - at least those involved in asthma - suggests a small study published ahead of print in the journal Thorax.

Social disadvantage has long been recognised as a major factor in greater vulnerability to sickness and death, and is also associated with more severe asthma in childhood, the evidence shows.

The research team assessed the genetic profiles of a group of immune system cells (T lymphoctyes) in 31 children between the ages of 9 and 18, all of whom had been diagnosed with asthma.

T cells are involved in the airway inflammation that occurs in response to particular triggers, such as dust or animal hairs, and which typifies an asthma attack.

The parents also reported on their children's day and night-time symptoms and whether these symptoms had prompted the need for emergency care during the previous six months. Half the children came from affluent privileged backgrounds, and half the children from disadvantaged backgrounds.

Genes regulating inflammatory responses were much more active in children from disadvantaged backgrounds than in children from privileged backgrounds.

This included those genes involved in producing powerful inflammatory chemicals, called cytokines, which induce stress responses and wound healing.

Children from disadvantaged backgrounds also had more severe asthma symptoms.

The design of the study means that definitive conclusions about cause and effect cannot be drawn, say the authors. But they add: “... the findings are consistent with the hypothesis that the larger social environment can get ‘under the skin' at the [genomic level].”

They also suggest that negative perceptions of the environment can alter biological mechanisms in the body, potentially explaining how disadvantaged backgrounds may get “under the skin.”