There are several thousand medical conditions that are due to differences in a person’s DNA sequence, often called pathogenic genetic variants or genetic mutations, these DNA glitches cause one or more of their genes not to work properly.
Genetic testing, looking directly at our DNA sequence, can be used diagnostically to identify the cause of a person’s medical condition or symptoms, or to screen healthy people in the population to identify people who are at risk of developing a genetic condition or passing it on to children.
Genetic testing is a means by which the NHS hopes to provide more personalised healthcare. Improving genetic testing (pdf) should help the NHS deliver more personalised care. Generation Genome (pdf), the Chief Medical Officer’s annual report for 2016, discusses the current state of genomic service provision in the NHS in England. It explores the potential of genomics to improve healthcare and prevent illness.
If an individual has a condition that is likely to be caused by a difference in the sequence of their DNA, genetic testing may be suggested.
Genetic tests can be used in a number of ways:
– To make a diagnosis or confirm a suspected diagnosis of a particular rare disease e.g. watch Alex’s story, produced by Genomics England
– To identify which individuals in a family are at risk of passing on a genetic condition to their children (Carrier testing) e.g. Cystic fibrosis, or thalassaemia
– Risk assessment in families with a known genetic disorder e.g. hereditary cancer syndromes, or certain heart conditions like Long QT Syndrome, or Hypertrophic cardiomyopathy
– Presymptomatic testing of people at risk of a late-onset genetic disorder e.g. Huntington’s disease
– Prenatal diagnosis of genetic conditions e.g. Down’s syndrome, or any condition that affects a particular family.
– To help prescribe the most effective medicine with the least side effects e.g. Abacavir (see Improving outcomes through personalised medicine, page 13 )
– To help maximise the chance that a transplanted organ will not be rejected
– To identify babies who are born with a treatable genetic condition
The East of England Genomic Medicine Centre works with many specialist NHS clinics across the region that support patients with rare diseases and cancers. It also works with various laboratories where clinical scientists look for specific changes in DNA, chromosomes or proteins.
- NHS Choices: Genetics – Overview
- UK: Professor Dame Sally Davies, Chief Medical Officer – Generation Genome Report
- NHS England: Professor Sue Hill, Chief Scientific Officer for England – Blog
- NHS England: Improving Outcomes through Personalised Medicine – Report