American scientists have attempted to genetically modify human eggs to eliminate inherited diseases such as ovarian and breast cancer.

Researchers at Harvard Medical School in Cambridge, Mass. removed ovary cells from a woman with inherited ovarian cancer to see if they could produce IVF embryos free of the disease, The Independent reported. The team used a new gene-editing technique called Crispr on ovarian tissue cultured in the lab to see if they could correct the defective BRAC1 gene that relates to inherited breast and ovarian cancers. 

The technique was developed a few years ago and has been used by scientists to correct inherited diseases in lab animals, as well as mend human genetic defects in non-reproductive human cells grown in a lab culture, according to the Daily Mail. Several labs may have already altered the DNA of human embryos, meaning that scientists could change a person's personality, including their intelligence and physical attributes. 

However, this type of genetic modification faces a lot of criticism. Among the critics is the Washington-based group Alliance for Regenerative Medicine, which opposes the work because it believes the technique is unethical and unsafe. 

"Philosophically or ethically justifiable applications for this technology - should any ever exist - are moot until it becomes possible to demonstrate safe outcomes and obtain reproducible data over multiple generations," the group said. 

Harvard geneticist George Church said the work was purely experimental, and they had no intention of fertilizing the eggs or transplanting them into a woman, The Independent reported. He is one of several experts who says there should be stricter controls on scientist who may be tempted to use the Crispr technique for human germ-line therapy on IVF embryos.