Gene-editing technology cures a genetic blood disorder

Posted Jul 22, 2017 by Tim Sandle
A next-generation gene-editing system has cured a genetic blood disorder in living mice using intravenous infusion treatment.
Normal blood cells next to a sickle-blood cell. Colored scanning electron microscope image.
Normal blood cells next to a sickle-blood cell. Colored scanning electron microscope image.
OpenStax College
Unlike gene-editing methods, the newly developed technology is able to be administered into living animals. The success of the trail could lead to a new therapeutic approach for the treatment genetic diseases of the blood, such as beta thalassemia and sickle cell disease. This is through targeting faulty genes in hematopoietic stem cells.
With the two primary disease types, beta thalassemia is a blood disorder that reduces the production of hemoglobin. Hemoglobin is the iron-containing protein in red blood cells, which carries oxygen to cells throughout the body. For those with beta thalassemia, low levels of hemoglobin lead to a lack of oxygen in many parts of the body, the consequence of which can be severe anemia. Sickle cell disease refers to a group of disorders that affect hemoglobin. Those with this disorder have atypical hemoglobin molecules called hemoglobin S, which can distort red blood cells into a sickle, or crescent, shape. The risks from the disease include anemia, swelling in the hands and feet, bacterial infections, and stroke.
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The new medical technology comes from Carnegie Mellon University and it uses state-of-the-art peptide nucleic acid molecules, based on a synthetic nucleotide technology. The peptide nucleic acid (gamma-PNA with a polyethylene glycol group on the side chain) is delivered together with donor DNA to repair a malfunctioning gene. The repair has been successfully demonstrated in mice, paving the way for human trials. The trial involved the use of a donor strand of DNA encoding the sequence for a functional hemoglobin subunit beta gene and a stem cell factor that enhances gene editing. Prior to the trial digital technology was used to model what would happen inside the body of the mouse.
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The new research is published in the journal Nature Communications, under the title "In vivo correction of anaemia in β-thalassemic mice by γPNA-mediated gene editing with nanoparticle delivery."
In related genetics-meets-technology news, researchers from Nanyang Technological University have reported that the ability to alter DNA accurately will help to foster in the development of personalized medicine to tackle human diseases that currently have few treatment options, such as neurodegenerative diseases like Huntington's disease, muscular dystrophies, and blood disorders like sickle cell anemia.