The clinical applications of genomic technologies

The clinical applications of genomic technologies are vast and offer opportunities to improve healthcare across the breadth of medical specialities.

We will explore some of these applications in more depth this week:

1. Gene discovery and diagnosis of rare monogenic disorders
   Genomic technologies can be used by clinicians from all specialities to diagnose their patients who have high-risk genetic errors causing disease. Researchers are using these techniques to identify new genes which cause genetic disease at an astonishing rate – over 4000 diseases now have a known single genetic cause, compared to around 50 in 1990.

2. Identification and diagnosis of genetic factors contributing to common disease
   Genomic technologies are increasingly being used to understand the contribution of both rare and common genetic factors to the development of common diseases, such as high blood pressure, diabetes and cancer.

3. Pharmacogenetics and targeted therapy
   Genetic information may be used to predict whether a person will respond to a particular drug, how well they will respond to that drug and whether they are likely to get any side effects from the use of a specific drug. This allows their treating team to make individualised decisions about the right drug treatment. In some cases, such as cancer, we can identify the genetic drivers of disease and then give drugs which specifically target that pathway. This is known as targeted therapy.

4. Prenatal diagnosis and testing
   Genetic diseases are often devastating and may cause significant disability and even death in childhood. Prenatal diagnosis of genetic diseases allows parents to make decisions about whether to continue with the pregnancy or to allow early diagnosis and possible treatment in utero or at birth. Whilst previous approaches to prenatal diagnosis could put the pregnancy at risk, new methods using genomic technology can look directly at the DNA of the fetus from a maternal blood test, without increasing the risk of miscarriage – this is known as non-invasive prenatal testing. The use of NGS and array technology in prenatal samples is also on the increase to improve diagnostic yields in a pregnancy.

5. Infectious diseases
   Sequencing the genomes of microorganisms which cause human infection can identify the exact organism causing symptoms, help to trace the cause of infectious outbreaks, and give information as to which antibiotics are most likely to be effective in treatment.

6. Personalised medicine
   As the exact DNA sequence of the genome of each human is unique to them, we will all have unique disease susceptibilities and treatment responses. Personalised medicine describes the use of our genetic information to tailor health care intervention to our own individual need.

7. Gene therapy
   Gene therapy involves the administration of DNA or RNA, in order to correct a genetic abnormality, or modify the expression of genes.

8. Genome editing
   Genome editing uses molecular techniques to modify the genome – genome editing can add in, cut out, or replace sections of the DNA sequence.

Talking point

Which of these clinical applications of genomics do you think will have the greatest impact on human health and why?