Institute of Child Health

Severe Combined Immunodeficiency (SCID), commonly known as ‘Bubble baby syndrome’, is a rare inherited disorder where the children have no immune system. A study led by researchers at Great Ormond Street Hospital NHS Trust (GOSH) and the UCL Institute of Child Health (ICH) in conjunction with Newcastle General Hospital (NGH) suggests newborn screening for this condition might greatly improve the chances of survival for these babies.

Diagnosis at birth has a significant benefit to those babies affected, researchers at GOSH/ICH and NGH have found, because they can be shielded from infection and transplanted earlier and in a more healthy condition. Researchers compared the infection rates and survival rates before bone marrow transplant, (BMT) and the survival rate post transplant, between two groups of children. The first was a group of children where SCID had not been diagnosed at birth and the second group were their younger siblings where the previous family history had allowed diagnosis of SCID at birth.

These findings are published today in the journal BLOOD (online first). Professor Bobby Gaspar, consultant in Paediatric Immunology, and lead on the study explains:

“SCID is a devastating condition and unless treated, children will usually die in the first year of life. The frequency of SCID in the UK is officially put at approximately 1:50,000 births but it may be more frequent than this. In this study, for the first time, we have been able to show what happens when babies with SCID are diagnosed at birth. We looked at the outcome of all the children seen at GOSH/ICH and NGH who were diagnosed at birth because a previous child was affected. We compared this with the outcome in the older child in the family who was diagnosed at a later age when they had picked up an infection.”

Results from the study were dramatic. In comparison to the older family member with SCID, babies diagnosed at birth had a significantly decreased number of infections (89% versus 17% respectively). Patients in the sibling cohort were also transplanted earlier, and had a dramatically improved survival outcome following BMT. The study outcomes showed that 35.4% of the late diagnosed group died before BMT and among the 31 late diagnosed children that went onto BMT, 38.7% (12 patients) died after the procedure. In comparison, only 1.7 % (1 patient) in the sibling group died before transplant and only 8.5% (5 patients) died after transplant. The transplant survival rate of the sibling group was 91.5% compared to 61.3% (p<.001) in the late diagnosed group.

The findings also show that the improved outcome was not dependent on the precise type of SCID or the form of ‘conditioning’ (chemotherapy or radiotherapy) used in the transplant. In principle, researchers expect the same outcome would be found in children offered gene therapy.

Professor Gaspar added “This study clearly shows how important it is to diagnose SCID early before children have had a chance to pick up an infection. The research shows that there would be a clear clinical benefit for a screening programme. We are working towards this in the UK and need to ensure that a quick and reliable test becomes available”

For further information contact the GOSH-ICH press office:

Hayley Dodman, press officer, 020 7239 3126, dodmah@gosh.nhs.uk