A new study has shown that whole genome sequencing can uncover new diagnoses for people across the broadest range of rare diseases investigated to date and could deliver enormous benefits across the NHS.

Genomics England says that he pilot study of rare undiagnosed diseases involved analysing the genes of 4,660 people from 2,183 families – all of whom were early participants in the 100,000 Genomes Project. Led by Genomics England, alongside NHS England, was established in 2013 to sequence 100,000 whole genomes from NHS patients and their families.

The study found that using whole genome sequencing (WGS) led to a new diagnosis for 25 per cent of the participants. Of these new diagnoses, 14 per cent were found in regions of the genome that would be missed by other conventional methods, including other types of non-whole genomic tests.

The pilot study shows that WGS can effectively secure a diagnosis for patients, save the NHS vital resources and pave the way for other interventions. For around a quarter of study participants, their diagnosis meant they were able to receive more focused clinical care. This included further family screening, dietary change, provision of vitamins and / or minerals and other therapies.

The study is the first to analyse the diagnostic and clinical impact of WGS for a broad range of rare diseases within a national healthcare system. The findings support its widespread adoption in health systems worldwide.

Professor Sir Mark Caulfield, former Chief Scientist at Genomics England, said: “We hope this major advance will enable rare disease patients worldwide to start receiving diagnostic whole genome sequencing where appropriate. Our findings show that deployment of this comprehensive and efficient genomic test at the first signs of symptoms, can improve diagnostic rates. This study has paved the way for clinical implementation of whole genome sequencing as part of the NHS Genomic Medicine Service.”