Post by Heimdallr on Oct 26, 2017 1:38:30 GMT
Two teams of researchers reported Wednesday they have come up with more precise ways to edit human genes, offering new hope to treat or even cure thousands of genetic diseases.
One team even reversed a hereditary disease — in cells in a lab.
Nothing’s quite ready for use in actual patients, but the reports show there’s more than one way to fix a broken genetic code. And the more precise the method, the less likely it is to cause side-effects or unexpected outcomes.
One new approach is a variation of a gene-editing method called CRISPR, and alters RNA instead of DNA, meaning it can be reversed. Another technique changes DNA, and would be permanent.
Each makes a change in just a single letter of the genetic code. But it’s an important letter, accounting for about half the simple, single-point mutations known to cause human disease.
Human DNA is made up of four compounds called bases: adenine (A), thymine (T), guanine (G) and cytosine (C). In the double-helix, ladderlike structure of DNA, A always pairs with T and G always pairs with C.
“Each of us carries two sets of 3 billion base pairs of DNA, one set from mom and one set from dad, in almost all of our cells,” David Liu, a researcher at the Broad Institute of Harvard and the Massachusetts Institute of Technology who led one of the study teams, told reporters.
“This human genome is predominantly made of just four letters: A, C, G and T.”
Various combinations of these four compounds spell out the instructions for amino acids, which in turn make up the proteins produced by cells.
So a mistake in one can cause a disease. “More than human 50,000 genetic changes are currently known to be associated with diseases,” said Liu, whose team’s experiments are reported in the journal Nature... More ... (NBC News - 25 Oct 2017)
One team even reversed a hereditary disease — in cells in a lab.
Nothing’s quite ready for use in actual patients, but the reports show there’s more than one way to fix a broken genetic code. And the more precise the method, the less likely it is to cause side-effects or unexpected outcomes.
One new approach is a variation of a gene-editing method called CRISPR, and alters RNA instead of DNA, meaning it can be reversed. Another technique changes DNA, and would be permanent.
Each makes a change in just a single letter of the genetic code. But it’s an important letter, accounting for about half the simple, single-point mutations known to cause human disease.
Human DNA is made up of four compounds called bases: adenine (A), thymine (T), guanine (G) and cytosine (C). In the double-helix, ladderlike structure of DNA, A always pairs with T and G always pairs with C.
“Each of us carries two sets of 3 billion base pairs of DNA, one set from mom and one set from dad, in almost all of our cells,” David Liu, a researcher at the Broad Institute of Harvard and the Massachusetts Institute of Technology who led one of the study teams, told reporters.
“This human genome is predominantly made of just four letters: A, C, G and T.”
Various combinations of these four compounds spell out the instructions for amino acids, which in turn make up the proteins produced by cells.
So a mistake in one can cause a disease. “More than human 50,000 genetic changes are currently known to be associated with diseases,” said Liu, whose team’s experiments are reported in the journal Nature... More ... (NBC News - 25 Oct 2017)
BELOW: Matthew Porteus, 51, professor of pediatrics at Stanford School of Medicine, holds test tubes of DNA to use for gene editing of stem cells at Lokey Stem Cell lab at Stanford University on Dec. 18, 2015 in Stanford, California.
