Molecular epidemiology

Epidemiological research within our group on the molecular level has focused on genetics of asthma and allergy in children. Gene-environment interactions constitute a primary target for investigation, taking advantage of our extensive experience in environmental epidemiology. Furthermore, we have access to several unique epidemiological materials. The BAMSE birth cohort is described above. Furthermore, the PARSIFAL study has 15 000 children, aged 6-12 years from five European countries, and a birth cohort has been established within the LifeGene project. Extensive information on exposure and phenotypes are available based on questionnaires, clinical investigations and biosamples, facilitating molecular epidemiology research.


In studies of gene-environment interactions we have shown strong synergy between GSTP1, TNF-alpha and traffic related air pollution or passive smoking for development of childhood allergic disease. Furthermore, we have confirmed that the asthma susceptibility gene NPSR1 is associated with asthma, rhinoconjunctivitis and sensitization also in children and unveiled interactions with farming exposure as well as with TNC. In a collaborative study we showed that a variant of MMP12 is associated with a positive effect on lung function in children with asthma and in adult smokers. In addition, we have participated in the first large-scale genome-wide association study on asthma, which indicated associations for six functionally interesting genes.

We plan to pursue molecular epidemiology research during the next few years primarily along three tracks:

  • Gene-gene and gene-environment interactions involving novel genes identified by GWAS and exposure to air pollution as well as passive smoking in relation to asthma and allergy in children
  • Gene-environment interactions in relation to lung function development in children
  • Genetic variability, epigenetics, gene expression and environmental exposures


All molecular epidemiology projects involve close collaboration with other groups at Karolinska Institutet (KI) and internationally. For example, genetic and epigenetic aspects are highlighted in collaboration with Juha Keres group at KI. To enhance statistical power combined analyses are performed with several epidemiological materials in Europe and North America. This involves collaboration with Imperial College London, the Helmholtz Center Munich, Utrecht University, Harvard Medical School and the University of British Columbia, Vancouver among others.


  • The Swedish Research Council
  • The Swedish Foundation for Strategic Research
  • The Swedish Environmental Protection Agency
  • The Swedish Research Council Formas


Associate professor

Erik Melén

Phone: +46-(0)8-524 875 08
Organizational unit: Environmental epidemiology

Professor/senior physician

Göran Pershagen

Phone: +46-(0)8-524 874 60
Organizational unit: Environmental epidemiology