Introduction to genomics

Genes act as instruction manuals that help our bodies know how to grow and develop. Humans have over 20,000 different genes, made up of DNA containing a sequence or code that instructs the body to perform a function. But what is the difference between genetics and genomics? Why is the use of genomics growing within the NHS? What is the impact on paediatrics and child health? Read on to find out more.

Genetics vs genomics: what is the difference?

Our genes instruct the body to perform functions: for example, the DNA might contain the code to make a protein. Some proteins may have a function at a single, specific time or place in the body, and the body may regulate the activity of genes, for example by switching certain genes on or off.

In humans, the genome is found in nearly every cell of the body (excluding mature red blood cells) and contains approximately 3 billion base pairs, making up all of the DNA. The genes actually contribute just 1-2% of this entire human genome. The remaining genetic material is not fully understood but includes structural and regulatory regions.

When there is an alteration, or pathogenic variant, in the DNA sequence, that affects the function of a gene, this can lead to a genetic condition. There are more than 7,000 different rare diseases, many of which are caused by a genetic disorder. So, although individual genetic conditions are rare, 1 in 25 children who are born in the UK will be affected by a genetic disorder.

There is often overlap between use of the terms ‘genomics’ and ‘genetics’, but generally genomics considers all the genetic material within an organism, whereas genetics is the study of how single genes are inherited.

Genomics in the NHS

Genomics, and the techniques used to study the genome eg Whole Genome Sequencing (WGS), has the potential to revolutionise care and treatment within the NHS. It can lead to faster, more comprehensive and more accurate diagnoses, reducing time spent in a ‘diagnostic odyssey’, and pave the way for more personalised and effective treatments. These techniques enable clinicians, as part of multidisciplinary teams, to perform a targeted assessment of large groups of genes which may be affecting the health or development of the patient.

Through the provision of national programmes such as the 100,000 Genomes Project and the Newborn Genomes Programme, there are rapid changes in how genomics is being embedded in clinical practice. The Genome UK Strategy and associated NHS Long Term Plan commits to harnessing the power of genomic technologies to improve population health, with an emphasis on equity of access and provision.

Genomics in paediatrics and child health

The national use, availability and adoption of genomics in clinical practice is ever expanding, and genomic technologies rapidly change. In England, the National Genomic Test Directory is regularly updated to inform clinicians what genomic tests are available for what indications and who can request them. For example, paediatricians working in PICU or NICU settings may be involved in requesting the R14 Rapid WGS test for acutely unwell children or neonates, whereas paediatricians in a general or community setting could request genetic testing for children presenting with intellectual disability, obesity or short stature. 

Doctors from most specialties, including paediatrics, will be expected to have an understanding of genomics, and be able to consent for, and request genomic tests relevant to their speciality. As genomic testing becomes more widespread, clinical geneticists will be able to provide support for more complex problems, rather than reviewing all children in which a genetic condition is suspected. 

Getting involved

The College's ambition is to support our members and children and young people and their families in preparing for the requirement for paediatricians to embed genomics into clinical practice. 

There are plenty of opportunities to get involved with the genomics programme at the College. We have established a Genomics Working Group; a group of experts who provide the decision making and strategic responsibility for the College. The ambition of the group is to create action and positions that will ultimately improve child health outcomes by addressing unmet need across the sector. 

As part of the genomics programme, the College runs events and opportunities that members can attend or be involved in. The College is also collaborating with Health Education England's Genomics Education Programme, to develop resources to prepare and equip paediatricians for the growing world of genomics. 

For more information, read our frequently asked questions, or contact us at