Until recently, children born with the rare genetic disease severe combined immunodeficiency (SCID) couldn’t expect to live longer than a year. Treatment is now available that can cure the disorder, but the key is getting to these children as early as possible, which is where newborn screening is vital.

SCID is the name given to a group of rare inherited disorders that cause severe abnormalities of the immune system. This happens when white blood cells, responsible for fighting infection, are missing or working poorly, which results in serious and often life threatening infections.

“The problem with SCID is that children born with the disease look absolutely fine,” explains Prof. Bobby Gaspar, Professor of paediatrics and immunology at the UCL Institute of Child Health.

“During the first few months they’ll generally be protected by the mother’s breast milk, but as they start to get exposed to coughs and colds, they don’t have the immune system to fight them, which could prove fatal.”

The National Screening Committee, the medical group responsible for authorising tests carried out newborns in the UK, is currently reviewing a proposal to add SCID to the group of nine diseases currently tested for at birth. The SCID test can be carried out using the same blood sample taken from a baby during the heel prick test, so there is no additional trauma. In the US, where more than three million babies have been screened for the disease, medical teams haven’t missed a single case of SCID.

Once diagnosed with SCID, babies can then be provided with the right care in a special unit where they’ll be isolated from infection and given special antibiotics to protect them. During this time, doctors can work out whether a bone marrow transplant or gene therapy is the best treatment to completely cure them from the disease.

“With newborn screening, we can, pretty much, go from having a disease that had a 100% mortality rate, to one that has a 100% survival rate,” concludes Prof. Gaspar. “We’ve been greatly encouraged by the research to date and are hoping that the test could be introduced as early as next year.”