Worldwide, over 300 million people are affected with asthma. It is known that both genetic and environmental factors influence who will suffer from asthma. Researchers from Michigan State University in the USA and The David Hide Asthma and Allergy Research Centre in the UK have shown that the smoking habits of mothers during pregnancy increase asthma risk in children who possess a specific genetic make-up.
The work was based on longitudinal studies of over 900 children born between 1989 and 1990 on the Isle of Wight, UK. These children were characterised for asthma parameters and various environmental exposures at their birth and at ages 1, 2, 4 and 10 years.
The interleukin-1 receptor antagonist gene was investigated, a gene that encodes a protein with anti-inflammatory activity. Previous studies have linked the interleukin-1 receptor antagonist to asthma in animal models and humans. This study demonstrated that the interleukin-1 receptor antagonist gene-asthma relationship is also affected by an environmental factor: smoking, specifically, mothers smoking during pregnancy. By examining the children for minor variations (termed genotypes) in the interleukin-1 receptor antagonist gene, the authors have shown that children with a specific genotype, whose mothers smoked during pregnancy, were at higher risk of suffering from asthma compared to other children.
On a public health level, the authors suggest that mothers should be advised to avoid smoking, especially during pregnancy, to minimise the risk of their children becoming asthmatic. They also suggest that genetic association studies on asthma should include environmental components in the analyses for a more comprehensive understanding of the mechanisms of asthma.
Title of the original article:
Interleukin-1R antagonist gene and pre-natal smoke exposure are associated with childhood asthma
The European Respiratory Journal is the peer-reviewed scientific publication of the European Respiratory Society (more than 8,000 specialists in lung diseases and respiratory medicine in Europe, the United States and Australia).
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