Complex diseases

Complex diseases include a number of the widespread illnesses such as allergies, diabetes, psychiatric disorders and
rheumatic diseases. These illnesses are caused by changes in several different genes in combination with lifestyle and environmental factors. This complex picture creates challenges for diagnosing patients and also often leads to a range of treatment outcomes.

Doctor recording the patient's statement

Many widespread diseases like allergies, asthma and other inflammatory diseases, diabetes, cardiovascular disease and several neurological and psychiatric diseases are caused by changes in several genes in combination with lifestyle and environmental factors. These diseases are referred to as complex diseases.

Challenges for complex diseases

The challenge of understanding complex diseases is that the cause of disease cannot be linked to individual genes or gene variants, but to changes in a large number of genes in combination with lifestyle and environmental factors. This combination of genetic and environmentally related factors makes it possible to divide diseases into different subgroups, so called phenotypes, with a variety of different responses to medical treatment.

Healthcare today has a limited ability to further expand on the diagnostics of complex diseases, on a genetic and molecular level, which makes it difficult to provide individualized treatment. As a result of this, there is an increased risk of a lack of response to treatment and a risk of adverse reactions. It could also entail increased indirect costs to society, in the form of for example sick leave. By using precision medicine, with the help of genetic analysis in combination with analysis of for example proteins in the blood, care providers can become able to better identify and characterise patients in order to more effectively choose the right treatment and lifestyle advice to the right patient.

National coordination for complex diseases

Within the framework of GMS’s collaboration with the Genomic Aggregation Project in Sweden (GAPS) we have initiated a working group for complex diseases. Our objective is to, in an introductory phase, identify a number of common complex diseases in Sweden where a genetic link has been identified, but where this information and knowledge is not yet used optimally in clinical practice. 

In the first projects we will be using genomic analyses in large existing Swedish studies (epidemiological cohorts) and patient material in order to be able to better diagnose diseases and predict responses to therapy and predict prognosis. These diseases may for example involve allergies, asthma, cardiovascular disease, diabetes, depression, Crohn’s disease, multiple sclerosis (MS) and rheumatoid arthritis. Genes important for the effect of drugs are also studied; pharmacogenomics. A number of pilot projects are ongoing in these areas. In the next phase we will be testing and evaluating genomic analysis for a number of disease areas in healthcare, and we will also be using genetic markers in different clinical studies in order to optimise preventive actions and treatment.

The collaboration between GAPS and GMS with the objective of bringing together scientists and clinicians that are working with complex disease is also supported by the SciLifeLab in the initiative Research Community Programs.

Co-chairs Complex diseases

Bo Jacobsson
Craig Wheelock
Åsa Johansson

Introduction disease areas

Genomic Medicine Sweden (GMS) focuses primarily on disease areas where there is currently definite evidence that suggests that genetic analyses can be used to diagnose disease, or where genetic deviations are important to prognostic assessment, choice of treatment and follow-up. We work primarily with rare diseases, solid tumours, hematological malignancies, infectious diseases and pharmacogenomics. GMS also has a particular focus on childhood cancer.