The DNA of 100,000 newborn babies is fully decoded

The genomes of 100,000 newborn babies in England are to be sequenced in a £105 million research program that could pave the way for a comprehensive newborn screening plan for rare genetic diseases.

Genomics England, a government-owned company, aims to read all the DNA from a nationally representative sample of babies shortly after they are born. The two-year project, carried out in partnership with the NHS, will start at the end of next year.

“Generating this evidence will enable policy-makers to make well-informed decisions about whether whole genome sequencing could be introduced as part of a future newborn screening programme,” said Richard Scott, Chief Medical Officer of Genomics England.

Currently, babies are given a “heel poke test” when they are four to five days old. Biochemical analysis of these tiny blood samples reveals nine potentially serious conditions so that treatment can begin as soon as possible.

Whole-genome sequencing — reading all 3 billion “letters” of a baby’s genetic code — is expected to increase the number of treatable conditions to about 200, many of which are extremely rare.

“We estimate that around 3,000 children are born in the UK each year who could benefit from this approach if adopted nationally,” Scott said. The number of tests requiring further testing is probably between 1,500 and 2,000 per 100,000 infants.

“The genetic variants we selected have been shown to cause serious childhood conditions that benefit from early detection and treatment,” said David Bick, principal clinician of the Neonatal Genomes Program.

One goal is to end the excruciating “diagnostic odyssey” that thousands of parents endure when young children develop a mentally or physically debilitating disorder for unknown reasons. Without genomic analysis, that usually takes four to five years, Scott said.

Participants are selected by NHS trusts across England to be as representative of the population as possible, with an emphasis on achieving the ethnic diversity often lacking in medical research projects, Bick added. Scotland, Wales and Northern Ireland may join later.

Selected parents are approached mid-pregnancy about potential participation, so they are ready for their baby to undergo more than the standard heel prick test. We explain the benefits and risks, including the wider implications of storing your baby’s genome for life.

The Genomics England project is one out of eight newborn sequencing studies are planned worldwide, but most of the others are smaller scale.

In its previous 100,000 Genomes project, which focused on patients with cancer and rare diseases, Genomics England used equipment from the US company Illumina to read the volunteers’ DNA. Scott said the sequencing technology to be used in the Newborn Genomes Program has not yet been determined.

Although the Newborn Genomes Program was designed in consultation with medical ethicists, several geneticists have expressed doubts that the NHS has the resources for extensive genomic screening in addition to its existing work.

“Using whole genome sequencing to screen newborns is a step into the unknown,” said Frances Flinter, clinical geneticist at Guy’s and St Thomas’ NHS Foundation Trust. “We should not compete using this technology until the science and ethics are ready.”