Gene therapy for children born without an immune system

This project is jointly funded by Sparks and charity partner Great Ormond Street Hospital Children’s Charity through the National Research Funding Call.

Babies born with severe combined immunodeficiency (SCID) have no natural defence against infections. This leaves them extremely vulnerable, as even a common cold virus could be life-threatening. Without treatment, most children with SCID lose their lives before the age of one.

Current treatments aim to ‘reboot’ the child’s immune system by fixing their own immune cells or transplanting cells from a healthy donor.  These can be effective in some patients but may rely on identifying a matching donor and can cause unwanted side effects such as blood cancer. There is an urgent need to improve treatment options for children with SCID, to allow them to live longer lives free of debilitating long-term side effects.

What is SCID?

SCID is caused by a genetic mistake in the child’s DNA – the set of instructions that determine how our bodies look, grow and function. Recent approaches to treating one common form of SCID have aimed to ‘correct’ this mistake, using a technique known as gene therapy. This involves taking blood cells from a patient, adding in a new, healthy copy of the affected gene, then giving the cells back to the patient.

The corrected gene slots into the child’s DNA at a fairly random location, not necessarily where it was originally located. That’s fine in some cases, but for some children it can lead to unwanted side effects such as leukaemia – a blood cancer.

Dr Alessia Cavazza at the UCL Great Ormond Street Institute of Child Health, wants to improve treatment options for children with this kind of SCID. She aims to use the latest techniques to place the corrected gene exactly where it belongs in the child’s DNA. This should ensure that it works as it would in a healthy person, with no risk of unwanted side effects.

Impact of research

SCID is a life-threatening condition for which there are currently no fully effective and safe treatments. If successful, Dr Cavazza’s project could dramatically change this situation, giving every child with this kind of SCID the chance of a new, working immune system. This would provide an alternative to current treatments such as bone marrow transplants, allowing families to avoid the uncertainty and anxiety of identifying a matching donor for their child. It could also provide a kinder treatment option, causing minimal side effects while allowing the child to life their life free from the constant risk of life-threatening infections.

The gene therapy team at the ICH has built a worldwide reputation for their expertise in the field. This project represents the exciting next stage of these treatments, which, if successful, could be applied to many other conditions in the future.

Improving gene therapy for children born without an immune system

Researcher: Dr Alessia Cavazza
Location: ICH
Grant: £41,589.28

Help fund more ground-breaking medical research for seriously ill children and their families.