̽��ֱ�� of Cambridge - Willem Ouwehand

Genomes front and centre of rare disease diagnosis

Anonymous — Wed, 24 Jun 2020 16:15:38 +0000

A research programme pioneering the use of whole genome sequencing in the NHS has diagnosed hundreds of patients and discovered new genetic causes of disease. Whole genome sequencing is the technology used by the 100,000 Genomes Project, a service set up by the government to introduce routine genetic diagnostic testing in the NHS.

̽��ֱ��results of the study, published in the journal Nature, demonstrate that sequencing the whole genomes of large numbers of individuals in a standardised way can improve the diagnosis and treatment of patients with rare diseases. It was led by researchers at the ̽��ֱ�� of Cambridge together with Genomics England.

̽��ֱ��researchers studied the genomes of groups of patients with similar symptoms, affecting different tissues, such as the brain, eyes, blood or the immune system. They identified a genetic diagnosis for 60% of individuals in one group of patients with early loss of vision.

̽��ֱ��programme offered whole-genome sequencing as a diagnostic test to patients with rare diseases across an integrated health system, a world first in clinical genomics. ̽��ֱ��integration of genetic research with NHS diagnostic systems increases the likelihood that a patient will receive a diagnosis and the chance that a diagnosis will be provided within weeks rather than months.

“Around 40,000 children are born each year with a rare inherited disease in the UK alone. Sadly, it takes more than two years, on average, for them to be diagnosed,” said Willem Ouwehand, Professor of Experimental Haematology at Cambridge, the National Institute for Health Research BioResource and NHS Blood and Transplant Principal Investigator. “We felt it was vital to shorten this odyssey for patients and parents.

“This research shows that quicker and better genetic diagnosis will be possible for more NHS patients.”

In the study, funded principally by the National Institute for Health Research, the entire genomes of almost 10,000 NHS patients with rare diseases were sequenced and searched for genetic causes of their conditions. Previously unobserved genetic differences causing known rare diseases were identified, in addition to genetic differences causing completely new genetic diseases.

̽��ֱ��team identified more than 172 million genetic differences in the genomes of the patients, many of which were previously unknown. Most of these genetic differences have no effect on human health, so the researchers used new statistical methods and powerful supercomputers to search for the differences which cause disease – a few hundred ‘needles in the haystack’.

“Our study demonstrates the value of whole-genome sequencing in this context and provides a suite of new diagnostic tools, some of which have already led to improved patient care,” said Professor Adrian Thrasher of the UCL Great Ormond Street Institute of Child Health (ICH) in London.

Using a new analysis method developed specifically for the project, the team identified 95 genes in which rare genetic differences are statistically very likely to be the cause of rare diseases. Genetic differences in at least 79 of these genes have been shown definitively to cause disease.

̽��ֱ��team searched for rare genetic differences in almost all of the 3.2 billion DNA letters that make up the genome of each patient. This contrasts with current clinical genomics tests, which usually examine a small fraction of the letters, where genetic differences are thought most likely to cause disease. By searching the entire genome researchers were able to explore the ‘switches and dimmers’ of the genome – the regulatory elements in DNA that control the activity of the thousands of genes.

̽��ֱ��team showed that rare differences in these switches and dimmers, rather than disrupting the gene itself, affect whether or not the gene can be switched on at the correct intensity. Identifying genetic changes in regulatory elements that cause rare disease is not possible with the clinical genomics tests currently used by health services worldwide. It is only possible if the whole of the genetic code is analysed for each patient.

“We have shown that sequencing the whole genomes of patients with rare diseases routinely within a health system provides a more rapid and sensitive diagnostic service to patients than the previous fragmentary approach, and, simultaneously, it enhances genetics research for the future benefit of patients still waiting for a diagnosis,” said Dr Ernest Turro from the ̽��ֱ�� of Cambridge and the NIHR BioResource.

“Thanks to the contributions of hundreds of physicians and researchers across the UK and abroad, we were able to study patients in sufficient numbers to identify the causes of even very rare diseases.”

Although individual rare diseases affect a very small proportion of the population, there exist thousands of rare diseases and, together, they affect more than three million people in the UK. To tackle this challenge, the NIHR BioResource created a network of 57 NHS hospitals which focus on the care of patients with rare diseases. Nearly 1000 doctors and nurses working at these hospitals made the project possible by asking their patients and, in some cases, the parents of affected children to join the NIHR BioResource.

“In setting up the NIHR BioResource Project, we were taking uncharted steps in a determined effort to improve diagnosis and treatment for patients in the NHS and further afield” said Dr Louise Wood, Director of Science, Research and Evidence at the Department of Health and Social Care.“This research has demonstrated that patients, their families and the health service can all benefit from placing genomic sequencing at the forefront of clinical care in appropriate settings.

Based on the emerging data from the present NIHR BioResource study and other studies by Genomics England, the UK government announced in October 2018 that the NHS will offer whole-genome sequencing analysis for all seriously ill children with a suspected genetic disorder, including those with cancer. ̽��ֱ��sequencing of whole genomes will expand to one million genomes per year by 2024.

Whole-genome sequencing will be phased in nationally for the diagnosis of rare diseases as the ‘standard of care’, ensuring equivalent care across the country.

̽��ֱ��benefits include a faster diagnosis for patients, reduced costs for health services, improved understanding of the reasons they suffer from disease for patients and their carers and improved provision of treatment.

Reference:
Turro E et al. ‘Whole-genome sequencing of patients with rare diseases in a national health system.’ Nature (2020). DOI: 10.1038/s41586-020-2434-2

Adapted from an NIHR press release.

Cambridge-led study discovers new genetic causes of rare diseases, potentially leading to improved diagnosis and better patient care.

This research shows that quicker and better genetic diagnosis will be possible for more NHS patients

Willem Ouwehand

National Human Genome Research Institute, National Institutes of Health

DNA Double Helix

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Licence type:

Public Domain

A BLUEPRINT for blood cells: Cambridge researchers play leading role in major release of epigenetic studies

cjb250 — Thu, 17 Nov 2016 17:00:15 +0000

̽��ֱ��studies are part of BLUEPRINT, a large-scale research project bringing together 42 leading European universities, research institutes and industry entrepreneurs, with close to €30 million of funding from the EU. BLUEPRINT scientists have this week released a collection of 26 publications, part of a package of 41 publications being released by the International Human Epigenome Consortium.

One of the great mysteries in biology is how the many different cell types that make up our bodies are derived from a single stem cell and how information encoded in different parts of our genome are made available to be used by different cell types. Scientists have learned a lot from studying the human genome, but have only partially unveiled the processes underlying cell determination. ̽��ֱ��identity of each cell type is largely defined by an instructive layer of molecular annotations on top of the genome – the epigenome – which acts as a blueprint unique to each cell type and developmental stage.

Unlike the genome, the epigenome changes as cells develop and in response to changes in the environment. Defects in the proteins that read, write and erase the epigenetic information are involved in many diseases. ̽��ֱ��comprehensive analysis of the epigenomes of healthy and abnormal cells will facilitate new ways to diagnose and treat various diseases, and ultimately lead to improved health outcomes.

“This huge release of research papers will help transform our understanding of blood-related and autoimmune diseases,” says Professor Willem H Ouwehand from the Department of Haematology at the ̽��ֱ�� of Cambridge, one of the Principal Investigators of BLUEPRINT. “BLUEPRINT shows the power of collaboration among scientists across Europe in making a difference to our knowledge of how epigenetic changes impact on our health.”

Among the papers led by Cambridge researchers, Professor Nicole Soranzo and Dr Adam Butterworth have co-led a study analysing the effect of genetic variants in our DNA sequence on our blood cells. Using a genome-wide association analysis, the team identified more than 2,700 variants that affect blood cells, including hundreds of rare genetic variants that have far larger effects on the formation of blood cells than the common ones. Interestingly, they found genetic links between the effects of these variants and autoimmune diseases, schizophrenia and coronary heart disease, thereby providing new insights into the causes of these diseases.

A second study led by Professor Soranzo looked at the contribution of genetic and epigenetic factors to different immune cell characteristics in the largest cohort of this kind created with blood donors from the NHS Blood and Transplant centre in Cambridge.

Dr Mattia Frontini and Dr Chris Wallace, together with scientists at the Babraham Institute, have jointly led a third study mapping the regions of the genome that interact with genes in 17 different blood cell types. By creating an atlas of links between genes and the remote regions that regulate them in each cell type, they have been able to uncover thousands of genes affected by DNA modifications, pointing to their roles in diseases such as rheumatoid arthritis and other types of autoimmune disease.

Dr Frontini has also co-led a study with BLUEPRINT colleagues from the ̽��ֱ�� of Vienna that has developed a reference map of how epigenetic changes to DNA can program haematopoietic stem cells – a particular type of ‘master cell’ – to develop into the different types of blood and immune cells.

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, which helped fund the research, said: “Our genes are critical to our health and there’s still a wealth of information hidden in our genetic code. By taking advantage of a large scale international collaboration, involving the combined expertise of dozens of research groups, these unprecedented studies have uncovered potentially crucial knowledge for the development of new life saving treatments for heart disease and many other deadly conditions.

“Collaborations like this, which rely on funding from the public through charities and governments across the globe, are vital for analysing and understanding the secrets of our genetics. Research of this kind is helping us to beat disease and improve millions of lives.”

Departmental Affiliations

Professor Nicole Soranzo – Department of Haematology
Dr Adam Butterworth – Medical Research Council (MRC)/British Heart Foundation (BHF) Cardiovascular Epidemiology Unit
Dr Mattia Frontini – Department of Haematology, and Senior Research Fellow for the BHF Cambridge Centre for Research Excellence
Dr Chris Wallace – Department of Medicine and MRC Biostatistics Unit

References

Astle, WJ et al. ̽��ֱ��allelic landscape of human blood cell trait variation. Cell; 17 Nov 2016; DOI: 10.1016/j.cell.2016.10.042
Chen, L et al. Genetic drivers of epigenetic and transcriptional variation in human immune cells. Cell; 17 Nov 2016; DOI: 10.1371/journal.pbio.0000051
Javierre et al. Lineage-specific genome architecture links enhancers and non-coding disease variants to target gene promoters. Cell; 17 Nov 2016; DOI: 10.1016/j.cell.2016.09.037
Farlik et al. Cell Stem Cell; 17 Nov 2016; DOI: 10.1016/j.stem.2016.10.019

Cambridge researchers have played a leading role in several studies released today looking at how variation in and potentially heritable changes to our DNA, known as epigenetic modifications, affect blood and immune cells, and how this can lead to disease.

BLUEPRINT shows the power of collaboration among scientists across Europe in making a difference to our knowledge of how epigenetic changes impact on our health

Willem Ouwehand

haha_works

Detail of Epigenome

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution