Genetic Epidemiology
Heritability studies have shown that genetic variation plays an important role in many diseases. The involved genes are, however, often unknown. In the Genetic Epidemiology group at Statens Serum Institut, we are looking for genetic variants that influence complex traits such as preterm delivery, birth weight, childhood eczema, age at first menstruation and childhood dental health.
Association with disease
Genetic association studies investigate whether genetic variants such as single-nucleotide polymorphisms (SNPs) differ in frequency between groups of disease cases versus healthy controls. Five years ago this was typically done at the level of a few hundred SNPs per person, and SNPs were selected in specific candidate genes thought to be important for the disease. It was often the case, however, that associations found in a study could not be replicated in subsequent independent investigations.
Nukleotidets placering på DNA-strengen kan variere fra person til person
Genome-wide association studies
The preferred approach to genetic association studies changed a few years ago due to two main developments. Firstly, information based on the international HapMap project vastly increased the knowledge about variation in the human genome. Secondly, new genotyping microarrays made it feasible to assess several hundred thousand SNPs per individual in short time and at reasonable costs. Thus, genome-wide assocation studies (GWAS) emerged as a hypothesis-free method of screening of the entire genome for disease related genetic variants. The GWAS approach has been remarkably successful, robustly identifying at least 2,000 common genetic variants for more than 150 diseases and traits so far.
In the Genetic Epidemiology group we are engaged in several GWAS. The largest study investigates preterm delivery, where 2,000 mothers and their 2,000 children have been genotyped for more than 500,000 SNPs each. In addition to ongoing analyses on the primary phenotype, we investigate secondary phenotypes, such as birth weight, childhood eczema and age at first menstruation. Other GWAS include studies of cleft lip and palate and Hodgkin's and non-Hodgkin's lymphoma, and more are being planned.
Biobanks and registers
Genetic epidemiology research at Statens Serum Institut benefits from a unique set of resources. Most notably, Biobank Denmark will harbor a comprehensive collection of biological samples, covering a large fraction of the Danish population. This, together with the detailed nation-wide health registers, allows very cost efficient genetic screening for many diseases.
Last revised 13 December 2011