DNA advancement may halt transmission of inherited diseases

London, April 15(ANI): It may soon be possible to prevent mitochondrial diseases, caused by mutations in the DNA of mitochondria, the energy-producing structures of the cell, from being passed on from a mother to the offspring.

British researchers have been successful in transplanting the genetic material in the nucleus of a fertilized human egg into another fertilized egg without carrying over mitochondria.

They used fertilized eggs donated by couples undergoing fertility treatment, and which were unsuitable for in vitro fertilization (IVF), for the research.

At this early stage, the sperm and egg nuclei, which contain most of the parental genes, have not yet fused. The researchers transferred this nuclei into another fertilized egg cell which had had its own nuclei removed.

As very little cytoplasm was transferred with the nuclei, the transfer left behind almost all the mitochondria from the donor egg.

They then grew the manipulated embryos for 6 to 8 days to see if they were able to continue development, and tested for the presence of donor mitochondrial DNA.

Douglass Turnbull at Newcastle University, one of the lead authors of the new study, said porting the nuclear DNA of an affected egg into an unaffected one could provide a solution for women at high risk of bearing severely affected children.

His team transferred nuclei from 80 embryos just after fertilization. A total of 18 continued to develop to beyond the eight-cell stage, and a small number of those reached the blastocyst stage of 100 cells.

On average, the procedure carried over about 2 percent of mitochondrial DNA from the donor to the recipient embryo, a number insufficient to cause disease.

"It's very exciting. It's a real shot in the arm for families that have had their children die from these various diseases," Nature quoted David Thorburn, a geneticist who studies mitochondrial diseases at the Murdoch Childrens Research Institute in Melbourne, as saying.

He added: "We've proved in principle that this sort of technique can be used to prevent transmission of mitochondrial diseases in humans."

Mutations in mitochondrial DNA are linked to diseases causing neurological, muscle and heart problems, as well as deafness and type 2 diabetes. (ANI)