March 11, 2011

Three-Parent Children Due Soon?

A fertility treatment designed to prevent some incurable inherited diseases, opens the possibility that children could be conceived from three biological parents.

British Health Minister Andrew Lansley asked the Human Fertilization and Embryology Authority (HFEA) to assess three-parent in-vitro fertilization (IVF) after researchers said they had mastered the technique using cloning technology, Reuters is reporting.

Newcastle University has refined the technique which swaps DNA between two fertilized human eggs and involves intervening in the fertilization process to remove malfunctioning mitochondrial DNA. This errant genetic coding can lead to conditions including fatal heart problems, liver failure, brain disorders, blindness and muscular weakness.

Mitochondria are the "batteries" of cells that are inherited exclusively from the maternal parent and are not present in the nucleus of a fertilized human egg which makes it is possible to inherit faulty mitochondria. An estimated 1 in 6,500 children are born with serious diseases caused by faulty mitochondrial DNA.

It is possible to extract the nucleus and transplant it into a second, donor egg with the resulting embryo having the nuclear DNA of the mother and father, but the mitochondrial DNA of the donor. The amount of genetic material contained in mitochondrial DNA is very small, only 13 protein-producing genes compared to the 23,000 genes inherited from parents.

Ethical concerns have been raised even with this very limited genetic relationship to a "third parent". "The more you manipulate embryos, the more risk there is," David King, head of Human Genetics Alert told Reuters.

Progress in this research is developing "very rapidly" and a review of the process, which would inform political debate, needs to start now. However researchers explain that they are not ready to practice this technique on patients as of yet. Alison Murdoch, head of the department of reproductive medicine at Newcastle University anticipates the review process to take about a year.

"As doctors we have a duty to treat disease and where possible to prevent disease. "With diseases for which there are no treatments the imperative to develop new treatments is even greater. Murdoch adds. "Of course no treatment is ever risk free and if there are risks we will need to quantify these so that doctors can discuss the relative risks and benefits with patients and their families."

A Department of Health spokeswoman tells BBC News, "This treatment is not currently possible under current legislation. "When the group reports back and based on the evidence available, we can decide whether it is the right time to consider making these regulations."

The HFEA panel is set to submit its report to the government next month.


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