How Much Can We Decide About Baby's Genes?

July 1, 2008— -- A British couple has used in vitro fertilization to keep their child free of a gene that promotes breast cancer -- an advancement supported by ethicists who worry, at the same time, where it will lead.

The Assisted Conception Unit at University College London Hospital announced this weekend that it had produced the first baby in the United Kingdom guaranteed not to have the breast cancer gene, which is thought to raise the risk of the disease to between 40 and 85 percent.

The father of the unborn child had a family history of breast cancer, with his sister, mother, grandmother and cousin all suffering from it at some point. Doctors scanned 11 fertilized embryos and implanted two of them that were found to be free of the breast cancer gene in the mother, who is now 14 weeks pregnant.

Doctors are quick to caution that this does not come close to eliminating the breast cancer risk entirely.

"Even if the baby doesn't have the breast cancer gene abnormality, that doesn't mean she won't get breast cancer," said Dr. Marisa Weiss, president and founder of breastcancer.org, and author of the upcoming breast cancer book "Taking Care of Your 'Girls'."

The screening represents a new phase in genetic testing on embryos, because it looks at a gene that poses a risk, rather than a disease itself, said Dr. Sherman Silber, director of the Infertility Center of St. Louis at St. Luke's Hospital.

He said that the idea of prescreening fertilized embryos has been around since 1990, when it was first used to avoid having children with cystic fibrosis.

A similar phenomenon has taken place, Silber noted, in families that have had autistic children and would like to avoid having another.

"For autism already in couples that have children, they're requesting [pre-implantation diagnosis] with sex selection, because, obviously, it's so much more common in boys than in girls," Silber said. "There are couples that have had several children with autism ... that have been requesting sex selection just to have only females."