The kids are all right: Children with 3-way DNA are healthy

With no sign of unusual health problems and excellent grades in school at ages 13 to 18, these children are "doing well," said embryologist Jacques Cohen at Saint Barnabas Medical Center in Livingston, New Jersey, where the treatment was done.

[...] the study of the children is timely because just last month, the first baby was born from a different procedure that also mixed genetic material from three people.

[...] finding no problem so far from the infertility treatment is helpful and "a good message" for people considering the disease-prevention procedure, Cohen said.

Genes in the mitochondrial DNA don't affect traits like eye and hair color but are important for keeping cells healthy throughout the body.

Cohen's hospital performed the infertility treatment between 1996 and 2001 on 33 couples who failed to conceive after roughly five tries at in vitro fertilization.

The parents of the quadruplets refused multiple requests for follow-up information; doctors know only that all four are alive and in high school.

At least two other clinics in the U.S. and several in other countries tried the technique after Cohen started it, but the U.S. work stopped after the Food and Drug Administration stepped in to regulate it.

[...] Dr. James Grifo, director of infertility treatment at New York University, said the results suggest that criticism of research that mixes DNA from three people appears unfounded.

In 1999, after years of experiments in mice, Grifo and colleagues made embryos with DNA from three people and transferred them to several patients' wombs, but no pregnancy resulted.

[...] Dr. Alan Copperman, director of infertility at Mount Sinai School of Medicine in New York, said the jury is still out on whether using a third party's genetic material is safe.

Most eggs that fail to develop normally, especially with older patients, are because of abnormal chromosomes, so tinkering with the cytoplasm is not likely