Genetic advance in Down’s syndrome
US scientists say they’ve moved a step toward having the ability to treat disorders because of an additional chromosome.
They have “switched off” the chromosome that causes the indications of Down’s syndrome in human cells within the lab.
The research, published in Nature, could at some point bring about new medical treatments for the condition.
Future work could be of real benefit to individuals with Down’s syndrome, said the united kingdom Down’s Syndrome Association.
Humans are born with 23 pairs of chromosomes, including two sex chromosomes, creating a total of 46 in each cell.
People with Down’s syndrome have three – instead of two – copies of chromosome 21.
This causes symptoms inclusive of learning disabilities and early-onset Alzheimer’s disease, in addition to a better risk of blood disorders and heart defects.
Gene therapy, which uses genes to regard illnesses, was attempted for problems because of a single defective gene. But in the past, the assumption of having the ability to silence the consequences of a complete chromosome had appeared beyond the realms of possibility, even inside the lab.
Now scientists on the University of Massachusetts Medical School have shown that, in theory, this could be possible but would take decades of study.
A team led by Dr Jeanne Lawrence inserted a gene called XIST into the stem cells of someone with Down’s syndrome grown within the lab.
The gene plays a task in normal cell development by switching off one of several two X chromosomes found in female embryos, ensuring daughters avoid a double dose of X chromosome genes.
The experiments showed that the gene was in a position to silence the additional copy of chromosome 21, helping correct unusual patterns of growth within the cells.
Dr Lawrence told BBC News: “The research implies that we’ve got a brand new way – in an instant – to review the cellular basis for Down’s syndrome, which can help identify drugs for Down’s syndrome.
“Collectively we’ve got made it conceivable – not necessarily possible or effective, that also must be proven – but conceivable that you would be able to use only a single gene to correct the over-expression of the complete chromosome. So it makes genetic therapy for Down’s syndrome more conceivable where it really wasn’t before.”
Commenting at the study, Carol Boys, chief executive of the Down’s Syndrome Association, said it was exciting new research from a really well-respected team.
“The findings may have serious implications for future work that can be of real benefit to those with Down’s syndrome,” she said.
“We’re an overly good distance from understanding how these findings might translate into clinical applications however it can be that they’re going to be of serious assistance within the look for conventional treatments for a number of the medical conditions that affect individuals with Down’s syndrome.”
Dr Lucy Raymond, from the dept of medical genetics on the University of Cambridge, said the gang had demonstrated a vital proof of concept.
“That is a thrilling breakthrough, but this process continues to be at an overly early [cellular] stage and we’re nowhere near seeing this procedure getting used within the treatment of Down’s syndrome in people.”