September 23, 2023


Future Depends on What You Do

Genome sequencing trial to test benefits of identifying genetic diseases at birth | Genetics

Genomics England is to test whether sequencing babies’ genomes at birth could help speed up the diagnosis of about 200 rare genetic diseases, and ensure faster access to treatment.

The study, which will sequence the genomes of 100,000 babies over the next two years, will explore the cost-effectiveness of the approach, as well as how willing new parents are to accept it.

Although researchers will only search babies’ genomes for genetic conditions that surface during early childhood, and for which an effective treatment already exists, their sequences will be held on file. This could open the door to further tests that could identify untreatable adult onset conditions, or other genetically determined traits, in the future.

“One challenging thing with newborn genomes is that they will potentially accompany people from cradle to grave,” said Sarah Norcross, director of the Progress Educational Trust (PET), an independent charity that improves choices for people affected by infertility and genetic conditions.

Ensuring the privacy of this data is therefore essential. “People must be able to trust that any data collected will only be used in the agreed way, and for the stated purpose,” Norcross said.

Each year, approximately 3,000 children are born in the UK with a treatable rare condition that could be detected using genome sequencing. Although newborn babies are currently offered a heel-prick test to screen their blood for signs of nine rare but serious conditions, such as sickle cell disease and cystic fibrosis, whole genome sequencing could enable hundreds more such conditions to be diagnosed at birth.

Currently, such diseases are usually only diagnosed once a child develops symptoms, often after months or years of tests. One such condition is biotinidase deficiency, an inherited disorder in which the body is unable to recycle the vitamin biotin. Affected children may experience seizures and delays in reaching developmental milestones, and have problems with vision or hearing, but early diagnosis and treatment with biotin supplements can prevent this deterioration and keep them healthy.

Dr Richard Scott, chief medical officer at Genomics England, said: “At the moment, the average time to diagnosis in a rare disease is about five years. This can be an extraordinary ordeal for families, and it also puts pressure on the health system. The question this programme is responding to is: ‘is there a way that we can get ahead of this?’”

The study aims to recruit 100,000 newborn children to undergo voluntary whole genome sequencing over the next two years, to assess the feasibility and effectiveness of the technology – including whether it could save the NHS money by preventing serious illness.

It will also explore how researchers might access an anonymised version of this database to study people as they grow older, and whether a person’s genome might be used throughout their lives to inform future healthcare decisions. For instance, if someone develops cancer when they are older, there may be an opportunity to use their stored genetic information to help diagnose and treat them.

According to research commissioned by PET earlier this year, 57% of the UK public would support the storage of genetic data in a national database, provided it were only accessible to the sequenced individual and healthcare professionals involved in their care. Only 12% of people opposed this.

Of greater concern would be the storage of a person’s genetic data for use by government authorities including the police, with the person being identifiable to those authorities. This was supported by 40% of people, and opposed by 25%. Norcross said that while Genomics England has good safeguards in place for providing research access to genomic data, “this risk can never be eliminated completely”.

Scott stressed that the purpose of the trial was to explore whether the potential benefits of newborn sequencing stack up, and engage in a genuine national debate about whether the technology is something people feel comfortable with. “The bottom line here is about us taking a cautious approach, and developing a view jointly nationally about what the right approach is, and what the right safeguards are,” he said.

Others raised concerns about the potential for false or uncertain results. Frances Flinter, emeritus professor of clinical genetics at Guy’s & St Thomas NHS foundation trust, and a member of the Nuffield council on bioethics, said: “Using whole genome sequencing to screen newborn babies is a step into the unknown. Getting the balance of benefit and harm right will be crucial. The potential benefits are early diagnosis and treatment for more babies with genetic conditions. The potential harms are false or uncertain results, unnecessary anxiety for parents, and a lack of good follow-up care for babies with a positive screening result.

“We must not race to use this technology before both the science and ethics are ready. This research programme could provide new and important evidence on both. We just hope the question of whether we should be doing this at all is still open.”