by Jeevan Singh
During the 2012 London Olympics the Prime Minister launched a project to bring the benefits of genomic medicine to NHS. The project, which is the largest of its kind in the world, aims to sequence the genomes of 70,000 NHS patients.
The 100,000 Genomes Project is an effort to map 100,000 genomes of patients with cancer and rare genetic conditions to try and find which gene mutations cause or increase the likelihood of getting these diseases. By the 1st of October 2018 the project had completed sequencing 87,231 genomes. This data will be combined with medical records and analysed and will then enable ground-breaking medical research, tailored genomic medicine and put the UK at the forefront of this newly emerging industry.
Genomics is a relatively young area of medicine that focuses on the study of the whole genome, which is different to genetics as it is the study of gene inheritance. Scientists are now in agreement that it is not a single gene that determines a trait or likelihood of developing a disease but it is determined by groups of genes which is why it is important to study the whole genome to diagnose and treat these inherited diseases.
One of the two types of diseases being studied in the project is cancer. Cancer cells occur when mistakes are made when copying the genome during cell division. When critical genes are affected it can start to multiply rapidly and form a tumour. The project aims to identify which type of mutation has occurred by comparing a blood sample and a sample of the tumour. There are two different types of tumour: germline and somatic. Germline mutations are inherited from your parents or occur spontaneously while the foetus is developing. These are detected after sequencing as the mutations don’t match the guide genome. Somatic mutations are caused by environmental factors and occur within the genome of the cancer cells. They are detected by comparing the genome of the sample taken from the tumour with the sequence from the blood sample, this cannot be done with germline mutations as every cell has the mutated genome.
The 100,000 Genomes project also aims to identify the causes of rare inherited diseases. NHS patients with rare diseases but without a molecular diagnosis (a diagnosis where the exact cause is known) were offered to have their genomes sequenced to try and find a diagnosis. Many patients may have already had genetic tests however these tests only look for changes in specific genes which is very limited compared to whole genome sequencing which looks for changes in the entire genome to increase the chances of finding the mutation that causes the disease. This is the start of a new era for the NHS as genomics promises to revolutionise treatment and diagnosis in the coming years. This project is just the start for the NHS as eventually it would like to use whole genome sequencing as part of its routine care. Genomic England (the company sequencing the genomes) says its legacy will be ‘a genomics service ready for adoption by the NHS, new medicines, treatments and diagnostics and a country which hosts the world’s leading genomic companies’. If it can deliver on these promises the quality of healthcare in this country will increase dramatically for all.
Reference
TJNS 