The gene responsible for sickle cell could be « repaired » by using the CRISPR-Cas9 gene-editing tool. This was announced in a study published in the magazine Nature by researchers at Stanford University School of Medicine.
Sickle cell is a widespread genetic disease affecting hemoglobin in red blood cells. It is due to a single gene mutation that makes a hemoglobin protein with symptoms including anemia, excruciating pain, and a higher risk of infections. This is a hereditary disease with autosomal recessive transmission resulting when both parents pass on a mutant allele to their child. Sickle cell disease is widespread throughout the world, affecting up to 5 million individuals. It was discovered independently in Africa and India, where the incidence is particularly high. Yet with the movement of people across borders, it is now reported in America, especially in the West Indies, Brazil and Western Europe. In 2013, 441 children with sickle cell disease were born in France; meaning one child affected for every 1,900 births.
Current treatments have greatly improved the lifespan for the affected patients, but they are limited. CRISPR-Cas9 could treat the disease at the root cause, where the red blood cells are formed. Thus the stem cells of the patients could be treated to repair the defective gene, those in the blood-generating cells of the bone marrow.
The American research team tested this gene-editing tool on stem cells from 4 sickle cell patients. Their results showed that in 30-50% of the diseased cells, the mutation had been repaired. The team plans to make an initial submission to the Food and Drug Administration (FDA) hoping to conduct a human clinical trial in 2018.
If the clinical trials confirm the results of these gene-editing modifications with CRISPR-Cas9, it would represent an enormous step-forward in healthcare to treat or to improve the quality of life for many patients.
Alliance VITA underlines the ethical issues related to this technique, if it was to be employed on germ cells or on human embryos. The slogan for the No GM Baby information campaign launched in May 2016 to alert and warn the public was: « Yes to therapeutic progress – No to transgenic embryos »
Tugdual Derville, Alliance VITA’s General Delegate and main defender for this appeal declares :
« We encourage genuine progress in science and medicine based on true care for humanity. In this case, we see therapeutic progress, to be supported and encouraged.”