Yale University Researchers Edit a Genetic Cure for Thalassemia

Researchers from Yale University have developed a new gene editing mechanism that corrects the mutation which leads to thalassemia, a form of anemia. Thalassemia is a rare condition which leads to anemia and has no known cure. Thalassemia Facts

• It is an autosomal recessive condition in which two copies of the mutated gene need to be present for the condition to be expressed.
• It occurs in 4.4 births for every 10,000 live births.
• The mutation could occur in the alpha or the beta gene.
• Alpha thalassemia is found largely in African population.
• Beta thalassemia is found in European population.

Gene Editing Mechanism

The Yale University researchers led by Peter M. Glazer, who is the professor of therapeutic radiology and genetics, along with the co-authors devised a gene editing system that, unlike other gene editing tools like CRISPR, did not give rise to unintended gene editing.

Key Protein

The researchers identified a key protein from the bone marrow that served to activate stem cells. Stem cells are the most responsive cells to gene editing. This protein was then combined with a synthetic molecule called PNA (Peptide nucleic acid), which was similar to DNA, and then bound to the gene that was targeted. The resultant structure was a triple helix. The synthetic cell then triggers a process that corrects the error in the gene.

Introduction into The Study

The PNA was then transported using nanoparticles that were injected into mice using an Intravenous (IV) line. In previous studies, gene editing tools were only studied in culture dishes and this was the first time that they were being introduced into animal structures.

The results of the study were extremely positive as the mice showed no signs of anemia. When the researchers tested the mice after 140 days, the hemoglobin levels in the blood were normal.

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Gene editing serves to correct the root cause of a disease condition and correction of phenotype or symptoms is the primary goal for any treatment procedure.

Thalassemia and Anemia

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Anemia is a condition in which the body does not have the required amount of hemoglobin in the blood, which leads to a drop in oxygen levels. Anemia is present in a large number of people, especially in young women, however, thalassemia is a genetic condition that triggers anemia due to mutations in the gene.

The symptoms of thalassemia include fatigue, breathlessness, poor growth and even bone deformations on the face. Folate supplements are necessary to increase the hemoglobin levels in the blood. In severe cases of thalassemia, blood transfusions are necessary but iron supplements should be taken with caution when blood transfusions are carried out. The lifespan of an individual with severe thalassemia is between 20 to 30 years if blood transfusions are not carried out regularly.

The current study that focuses on correcting the gene mutations that lead to lowered hemoglobin in the blood will serve to bring hemoglobin levels to normal limits, deeming blood transfusions unnecessary. Continued research and development of a method that can be used on human trials will render the research a landmark in the quest for a cure for thalassemia.

References:

1. Thalassemia - (https://medlineplus.gov/ency/article/000587.htm)
2. Yale scientists edit gene mutations in inherited form of anemia - (https://www.eurekalert.org/emb_releases/2016-10/yu-yse102416.php)

Source-Medindia