Question: Why are genetics and genomics important to our health?

Gemma Chandratillake answered on 15 Mar 2018:

So, genetics is all about looking a one particular gene, and genomics is about looking at lots, or all of our genes. We can use both in healthcare, depending on the particular situation. Here are some areas in which our genetics impacts on our health:
1) 1 in 17 people have a rare disease, and most of these diseases are caused by a change in their genes. There are thousands of rare diseases, so only a few people have each one. That makes it very difficult for doctors to recognise these patients and to diagnose them properly. If you don’t have a proper diagnosis, you are in the dark as to how your health will be affected, it is difficult to access support services, it is difficult to say whether other family members could be affected. Often people with rare diseases go to lots of hospital appointments and have lots of tests but get no answer. Genomics (sequencing all the genes from a person), can help to find a diagnosis for a lot of these people, which means that they can access proper care and services and find out what it means for their family members. In some cases, there are even treatments available that they can now get.
2) Cancer is a genetic disease. It is always caused by changes that happen to the DNA during a person’s life. If we look carefully at the changes that have happened in a person’s tumour by sequencing the DNA of the tumour, we can understand more about what is making that cancer grow, and decide which treatment to give the patient. The aim here is to personalise the treatment of cancer to the genetic changes in the tumour rather than, say treating all breast cancers in the same way. In this way, treatments should be more effective, and treatments that won’t work (which cause bad side effects and cost a lot of money too) can be avoided.
3) 1 in 15 people who go into hospital do so because they have had a bad reaction to a medication that they were prescribed. In some cases, this could have been avoided as we know about some genetic markers that tell us who will react badly to certain medications. So, we would like to do more of this type of testing before prescribing so that we can personalise the medicines that we prescribe to the patients ability to respond to them and to minimise the chance of a bad reaction.
Here is how we are thinking about things for genetics and genomics in the NHS going forward:
https://www.england.nhs.uk/wp-content/uploads/2016/09/improving-outcomes-personalised-medicine.pdf
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/631043/CMO_annual_report_generation_genome.pdf