UPSC Express

Hunter’s Syndrome

• Hunter’s syndrome is a rare genetic disorder that occurs as a result of a mutation in a gene that produces an enzyme that helps in breakdown of certain sugars.
• The enzyme activates parts in the cells in order to breakdown sugars.
• However, in the absence of the enzyme, these sugars build up in tissues causing damage to organs such as the heart, lungs, brain etc.

First in-vivo Gene Editing

• In a bid to treat Hunter’s syndrome, scientists conducted gene editing inside the human body (in-vivo) for the first time ever using a gene editing technique called zinc finger nucleases (ZNF).
• Under the zinc finger nucleases (ZNF) technique, the corrective gene was inserted in the DNA of the patient through Intravenous therapy (IV).
• While the in-vivo gene editing tool was found to be safe, its therapeutic efficacy could not be completely established.
• As per the Preliminary results, patients now have a corrective gene at very low levels, which may not be enough to make the therapy a success. However, it still represents a scientific milestone toward one day doctoring DNA to treat many diseases caused by faulty genes.
• The therapeutic efficacy will be established once the patient’s body will start making the missing enzyme that breaks down the sugars on its own.

What is Gene Editing?

• Gene editing is a form of gene therapy that is used to rewrite DNA.
• DNA is a biological code that guides the building of an organism.
• If there is a problem in this information storehouse, generally called a mutation, the organism may not be able to manufacture that protein and hence that organ in the body.
• Thus, a mutation could lead to absence of an organ or presence of a defective organ in the body.
• Gene Editing is the process of disabling faulty genes, correct the harmful mutation, insert a missing gene or change the activity of specific genes in living organisms.

Applications of gene editing

• Treating genetic disorders like cystic fibrosis, sickle cell anaemia and muscular dystrophy.
• Gene editing is widely used to modify immune cells to fight cancer, increase resistance in HIV cases.
• It can be used correct defective genes in human embryos and prevent inheritance of genetic disorders
• Gene editing techniques are faster, cheaper and more precise than conventional techniques in genetic modification of crops.
• Further gene editing techniques are extremely helpful in gene therapies including building of new diagnostic tools, drugs, organ transplantations etc.