Many rare diseases have an underlying genetic component, and are often the result of a single missing or defective gene.

Professor Bobby Gaspar is an expert in paediatrics and immunology at Great Ormond Street Hospital and the UCL Institute of Child Health. When not treating patients, Gaspar develops gene and cell therapies to treat rare diseases of the immune system — diseases such as severe combined immunodeficiency (SCID), where babies are born without functioning white blood cells and, if left untreated, are unable to fight even common infections. These babies are unlikely to survive longer than a year.


Correcting diseases with bone marrow gene therapy


“Where the patient’s white blood cells don’t work or develop properly and are causing severe immune deficiencies, we take a sample of bone marrow (full of stem cells) and introduce a working copy of the defective gene into these cells before returning them – now gene-corrected – to the patient.

This means their cells now have the right information to grow an immune system that allows their bodies to fight infections properly,” says Gaspar. This process is involved in treating diseases like SCID.

Since the human genome was mapped more than 20 years, ago, developments in gene and cell therapy have been closely researched and are delivering “very promising” results. Treatment for these rare disorders is currently only accessible at a few specialist hospitals, mainly in Europe and the United States, but now, treatments are being made more widely accessible.

“Many rare diseases have limited treatment options but by correcting a patient’s condition using their own cells, we’re able to treat them far more safely than by using the current alternative treatments," he says.


Cancer patients could benefit from rare diseases treatments


Over the next five years, Gaspar predicts that more gene therapy will be developed for a wider variety of rare diseases, including rare cancers, as well as more common conditions like sickle cell anaemia.

As gene therapy becomes more common, patients will be able to access treatment without long — and sometimes arduous — journeys to specialist centres. “Changing treatment pathways will mean that, rather than patients having to travel, cells can be taken and transported to a manufacturing site where gene modification of the bone marrow cells can take place,” says Gaspar. Once modified, cells can be transported back to the local facility and re-introduced to the patient.

One such specialist treatment centre scheduled to open at the end of 2018 is the Zayed Centre for Research into Rare Disease in Children, based at Great Ormand Street Hospital in London. As well as a clinical outpatient department, it will also include a large gene and cell therapy facility as well as research laboratories focused on identifying the genetic basis of a wide variety of rare diseases.

“It means effective treatment will be made available to children on a global basis,” says Gaspar.