Op-Ed

Black and white photo, in bird's eye view, displaying a spiral staircase.

A healthy baby boy has been born after he was conceived using a "three-parent" technique to manipulate his DNA, doctors said Tuesday.

Fertility specialists from New York, Cincinnati and Britain did the experimental treatment in Mexico. It has not been approved in the U.S. It has been approved in Britain.

It's not the first so-called three-parent baby, but it's the first time modern techniques have resulted in a healthy birth, the doctors said.

The mother carries genetic defects known to cause Leigh syndrome, an incurable, progressive disorder in which brain cells gradually die off, causing a range of symptoms. The treatment, in which a second woman's DNA is used to replace the faulty genetic material, is aimed at producing a child free of the disease.

"She had four pregnancy losses and two deceased children at age 8 months and 6 years from Leigh syndrome," Dr. John Zhang of New Hope Fertility Center in New York and Guadalajara and colleagues at Cincinnati Children's Hospital and Reprogenetics in Britain and in Livingston, New Jersey wrote.

The doctors have given a bare-bones rundown...