Newborn babies
Newborn babies rest in cots. Reuters

New details about the baby who was conceived with the DNA of three parents was released Monday. The baby was born in April 2016 to two parents from Jordan.

The mother in the case carries Leigh syndrome, a rare neurological disease that affects the central nervous system and leads to neurological deterioration, in her mitochondrial (small cells) DNA but does not suffer from the disease. She had previously lost children to the disease, according to a study on the case in Reproductive BioMedicine Online. To try to prevent the couple’s next child from suffering the same fate, they tried the risky three-parent technique for conception.

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What is the three-parent technique?

The controversial procedure was done at the request of the two parents who had previously lost two babies to a deadly disease carried in the mother’s genetic makeup. Doctor John Zhang of New Hope Fertility Center in New York City developed the “three-parent” technique that involves removing the nucleus of the mother’s egg and using it to replace the nucleus of a donor egg before fertilization and implantation. This is also called a “spindle nuclear transfer,” and It’s controversial because it may make children born from it sterile, however it is legal in the UK.

Did it work?

When the baby was born only two to nine percent of his mother’s mitochondrial DNA. The researchers hope that with less than 10 percent of his mother’s mitochondrial DNA he won’t have Leigh. At seven months of age he was healthy and doing well, although doctors noted in their research that he would have to be closely monitored for long-term follow ups. Those visits would be once a year after the age of three if he continues to be asymptomatic, and doctors plan to test his fertility function at the age of 18.

Other possible reactions to the mitochondrial replacement could become apparent further down the line as well. When performed in mice, some developed other neurological or metabolic problems. So only time will tell how successful the treatment really is, but it’s a sign for the medical field that the possibility of eradicating some deadly syndromes could be within reach.