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Documentation for clinical application of genomics

Genomics in the health care system

Our personal genetic background naturally means that we react differently to environmental factors, lifestyle, diseases and treatment. However, medications are developed for the 'average person'. Based on genomic information, doctors in the future are expected to be able to diagnose patients more individually and recommend specific treatment - for instance a specific choice of medication, an individualized dosage or specific considerations regarding side effects.
     Since doctors diagnose according to documented knowledge, diagnosis based on genomic information of patients requires existing knowledge enabling the linking of genomic information to disease understanding and treatment. The field of genomics is however still relatively new, and limited documentation of larger groups and few disease areas exists. Even so, small-scale studies and statements demonstrate how genomics can advance diagnosing and treatment procedures in different situations.
Information from WHO about potential advantages of genomics
Overview: clinical application of genome research (2014)

Socio-economic rationale

When a disease is associated with genetic components, or when standard treatment hasn’t been effective, genetic diagnostic examinations are often carried out. If the first examination doesn't prove effective, sometimes the patient must undergo several. Every interaction with the healthcare system means more expenses are incurred.
     An American study examined how genomics is likely to advance treatment procedures. It was concluded that regular genetic examinations resulted in an accurate diagnosis 42 % of the time, while 8 % of patients didn’t seem to have a genetic component. The remaining 50% of patients would undergo further genetic tests that averagely cost 25,000 USD for one test (minimum price estimate). It was further concluded that genomic information could be utilized for diagnosis for half of the patients that had to undergo more than one genetic test. This price estimate is relevant for patients that, according to a doctor, need a genetic examination. In comparison, the cost of one genome sequencing is now below 1,000 USD (analysis and consultation excluded).
     For the entire group of patients in the study described above, a genomic examination would thus be expected to diagnose nearly 67 % of all cases the first time around. Thus, this study demonstrates possible cost reductions as a result of utilizing the genomic information of patients.
American study of genetic information in the procedure of diagnosing (2014)

Tolerance of different medications

A person's genetic background influences the effects of medicine as well as the side effects associated with it. One example is the anti-HIV medication Abacavir that has been used for treatment since 1998. Usually, the medication is tolerated, but nearly 8 % of patients are hypersensitive which can prove fatal. The hypersensitivity is caused by a genetic variation in HLA-B*5701 (a part of the leukocyte antigen B system). Two clinical experiments have proven that genotyping the HLA-B*5701 and adjusting the treatment will reduce the side effects, which is why genetic testing has been recommended in many countries.
Comment from European Medicines Agency on Abacavir from 2000

Monogenic disorders

Monogenic disorders are diseases caused by a single genetic variation. Many rare and difficult-to-diagnose, monogenic diseases exist which makes it difficult to pinpoint the specific disease at hand. Yet, once the genetic background has been discovered, a genetic diagnose is easy. Genomics is a helpful tool in the diagnosis of monogenic disorders. If a doctor has access to information about a patient's genome at the first meeting, it will be much easier to diagnose a monogenic disease - and choosing the correct method of treatment afterwards. It should be mentioned, however, that the diagnoses of rare diseases often require data from very large groups of people. Since the disease is rare, data from many individuals are needed to find the few individuals suffering from a particular disorder.
Information from WHO regarding monogenic illnesses

Cancer

Treating cancer today is based mainly on classifying the organ that has been infected. Since the cause of cancer is always associated with genetic changes, studies have, not surprisingly, demonstrated that the genetic profile is important for the choice of treatment method. A vast cancer project has identified a panel of genes that can help with the profiling of tumours in different cancer types.
Cancer profiling according to method of treatment (2011)
Cancer Atlas project (2013)

Lifestyle diseases

Welfare diseases such as cardiovascular diseases, metabolic syndrome (including diabetes) and Alzheimer’s disease are all examples of very complex disorders where both genetic as well as environmental aspects are involved in the formation of the disease. In such instances, a diagnosis and treatment based on genomics can rarely stand alone. This means that genomic information from an individual patient can only partially contribute to the entire examination.

Prognosis for healthy people

Analytical methods exist that attempts to predict a genetic risk profile for a certain genome based on general knowledge of genome variations and physiology. Based on this technology, different companies interpret genetics data or entire genomes in order to sell analyses and counselling regarding lifestyle choices or the risk of certain illnesses. Yet, this sector is now mostly subject to public control in several countries, seeing as predictions are associated with uncertainty as soon as they are categorized as complex and/or environmentally dependent.
A critical view on expectations for the clinical application of genomics (Scientific American 2012)

Conclusion

In GenomeDenmark our standpoint is that it will possible to utilize genomic information large-scale and effectively in the health care systems ahead. Already today, genomics are used for diagnosis of patients (although still few), However large-scale coupling of research in genomics, biobanks and information in health registers will advance our understanding and improve our knowledge base for the benefit of our health care system. With cost-efficiency improvements, diagnosing and treatments will become more effective in the future, which is highly relevant for disease areas with genetic components.