Gene editing breakthrough could open up new treatments
Scientists say they have filled in the ‘‘final missing piece in the puzzle’’ in editing human genes, with the potential to unlock treatments for ‘‘devastating’’ incurable diseases.
The new technique, developed by researchers in South Korea, could eventually help to treat other types of disease, including Parkinson’s and Alzheimer’s, experts suggest.
Mitochondrial diseases are conditions that are serious and often fatal, while also largely untreatable.
Most DNA is stored in the central nucleus of human cells, but some is locked up in smaller pockets in the cell called mitochondria. These act as powerhouses for our cells, generating the energy they need to function.
Malfunctioning mitochondria can lead to conditions that include fatigue and weakness, impaired vision and muscular dystrophy. Many have neurological symptoms that can affect brain function, including memory.
These diseases are usually inherited from the mother, and affect about one in 5000 people. But more common diseases, including Alzheimer’s and Parkinson’s, have been linked by some studies to malfunctioning mitochondria, and potentially to defects in the DNA within.
DNA errors are like spelling mistakes in the code – made up of the letters A, G, C and T – that forms the human genome, and scientists have been developing ways to correct them.
Techniques such as the Nobel Prize-winning Crispr process, which can target, snip out and replace faulty sections of genetic code, have been successful at correcting mistakes in DNA found in the cell nucleus, but cannot be used to access DNA in mitochondria.
Scientists at Harvard University developed a way to correct one type of spelling mistake in this DNA, changing a C to a T, but the missing piece was correcting the remaining DNA typo: how do you change an A to a G?
Now, researchers at the Centre for Genome Engineering at the Institute for Basic Science in Daejeon, South Korea have found a way to access the mitochondria, unwind the DNA’s double helix, and correct errors.
Dr Kim Jin-Soo, an author of a study published in the journal Cell, said scientists would be able to perform trials in live animals, editing their DNA to recreate certain types of disease so that drugs and therapies could be tested.
Dr Michal Minczuk, an expert at Cambridge University, said the development was ‘‘very exciting’’. He said trials would be needed, with human treatments a decade away.
Chris Carroll, a geneticist at University of London, said the technique could target mitochondrial diseases that were ‘‘devastating’’.
Professor Robert Lightowlers of Newcastle University hailed the breakthrough, saying: ‘‘When we started, the holy grail of actually being able to edit this genome was so far away, it was just impossible.’’