Just last week, for instance, a British scientific panel decided that the fertility technique is not unsafe for patients who suffer from mitochondrial disease. The decision hints that British government may soon amend legislation that currently bars the procedure, called mitochondrial replacement (MR), from entering human trials. Thus, the first baby with three genetic parents will likely be British, and the two countries that are seriously considering human trials are unlikely to reach a consensus before its birth. But some people — an estimate 4,000 people in the US each year — are born with faulty mitochondrial DNA, which can cause a range of health problems, including seizures, blindness, heart problems, and liver disease.