In up to 40 percent of the blood cells, the disease-causing mutation was reversed using the CRISPR/Cas9 approach. 'The idea is to correct that particular mutation, and then stem cells that have the correction would differentiate into normal blood cells, including red blood cells,' said Professor Gang Bao at Rice University in Houston, Texas, and lead author of the study. 'Those will then be healthy blood cells.'
The team then implanted the edited human cells into the bone marrow of mice. Even 19 weeks after this transfer, the cells retained their induced correction, indicating that this is a stable change within the cells.
This raises the hope that genome edited cells could be a potential treatment for patients. However, this will need to be confirmed in future clinical trial, as Professor Bao remarked: 'We still don't know whether repairing as much as 40 percent of the cells is enough to cure a patient.'
The study, presented at the American Association for the Advancement of Science's annual conference in Austin, Texas, also found unintended changes in the genome of the corrected cells. Professor Waseem Qasim at the University College London, who was not involved in the study, told iNews that 'the question is how many cells may have other parts of their DNA change'.
Sickle cell disease affects 14,000 people in the UK and causes anaemia, infections and strokes. A single mutation in the beta-globin gene causes red blood cells to adopt an abnormal sickle shape, leading to blockages of the blood vessels, pain and potential organ damage. According to NHS Choices, current treatments for sickle cell disease involve treating the symptoms, rather than the underlying cause of the disease.