‘Matching’ DNA may make for healthier three-parent babies

PARIS (AFP) — Better matching the DNA of egg donors and recipient mothers-to-be may limit the risk of transferring disease-causing mutations to so-called three-parent babies, a study suggested Wednesday.

While further work is needed, the study adds to the fast-growing field of in-vitro fertilization for women with damaged mitochondrial DNA (mtDNA) — the type inherited solely from our mothers.

An egg donor — the third parent along with the couple who go on to give birth to and raise a baby — should be selected whose mtDNA is genetically closely related to that of the recipient mother, the authors wrote in the journal Nature.

Every cell in the human body holds about 23,000 genes, almost all of them in the nucleus — so-called nuclear DNA.

But 37 genes reside in tiny structures called mitochondria, which are the batteries of cells, turning sugar and oxygen into energy.

Nuclear DNA is transfer to offspring by both the father and mother, but mitochondrial DNA is inherited from the mother alone. Some women have damaged mtDNA, which if transferred to their children can cause a variety of debilitating and untreatable diseases.

Women with mitochondrial mutations can have healthy children via in-vitro fertilization, using a technique called mitochondrial replacement therapy.