Gene–Environment Interactions—What Can These Tell Us about the Relationship between Asthma and Allergy?

Abstract

Asthma is a common condition, which is associated with atopy and allergic conditions including hay fever, eczema, and food allergies. Asthma and atopy are both complex conditions where genetic and environmental factors are implicated in causation. Interactions between genetic and environmental factors, likely via epigenetic mechanisms, are widely thought to be important in determining the risk for developing asthma and atopy. The nature of the relationship between asthma and atopy is unclear and the answer to the question “does atopy cause asthma?” remains unknown. This review explores the relationship between asthma and atopy from a gene–environment interaction perspective and tackles the question “are similar gene–environment interactions present for asthma and atopy?” The main finding is that gene–environment interactions are described for asthma and atopy in children but these interactions are seldom sought for both asthma and atopy in the same population. In the few instances where a gene–environment interaction is related to both asthma and atopy, there is no consistent evidence that similar interactions are common to asthma and atopy. Many plausible gene–environment interactions for asthma and atopy are yet to be explored. Overall, from the gene–environment interaction perspective, there is absence of evidence to better understand the complex relationship between asthma and atopy.

Shared prenatal impacts among childhood asthma, allergic rhinitis and atopic dermatitis: a population-based study

“…Perinatal environmental factors and gene–environment interactions have been implicated in the development of childhood allergic diseases in addition to genetic factors [17, 18]. In line with our data, previous studies have shown that a high urbanization level was associated with childhood allergic diseases, so-called hygiene theory [19, 20].…”

“…The impact of maternal and perinatal factors on childhood allergic diseases can be attributed to both genetic susceptibility and gene–environment interactions [17]. Indeed, asthma, AR and AR are prevalent atopic disorders of complex etiology, and these three diseases are frequently observed as the atopic march, indicating the potential shared underlying immunological mechanisms among these three allergic diseases [7].…”

The intersect of genetics, environment, and microbiota in asthma—perspectives and challenges

“…Kauffmann and Demenais 3 and Turner 13 have previously reviewed gene-environment interactions in asthma, and several major examples are described in this review. However, there is currently no estimate of how much these interactions contribute to the final asthma phenotype.…”

What is the evidence for interactions between filaggrin null mutations and environmental exposures in the aetiology of atopic dermatitis? A systematic review

“…A recent review on allergic diseases highlighted that several studies exploring GEI in AD exist, yet findings have not been synthesized (e.g. in a systematic review) . Our objective was to perform a systematic review of the evidence for GEI in AD, focusing on interactions with the FLG null genotype, because this is the strongest and most widely replicated AD genetic risk factor, and because the role of filaggrin in skin barrier function provides a priori support for a hypothetical GEI effect.…”