While Alana still considers herself to only have one mother and one father, she notes that she’s received a small amount of DNA from a third person. This DNA was contained in some donated mitochondria, which are cell structures that act like tiny factories, producing the energy the cells need to function.
According to Charlotte Pritchard at BBC News, Alana is one of just 30 to 50 people in the world who have received mitochondria - and therefore DNA - from a third person. "She was conceived through a pioneering infertility treatment in the US, which was later banned,” says Pritchard.
While Americans can no longer go through this process, the British Government is currently considering making a similar process, called 'mitochondrial replacement', legal in the UK, to try and eliminate a number of genetic diseases. If the motion passes through parliament, the UK will be the only country in the world where a baby can legally be born using the genetic material of three people.
Alana's mum, Sharon Saarinen, tried for 10 years to concieve through IVF procedures, and when unsuccessful, went through a new procedure called 'cytoplasmic transfer' at the St Barnabus Institute in the US. The cytoplasm is a soft structure within a cell that contains mitochondria. "We felt that there was a chance that there was some element, some structure in the cytoplasm, that didn't function optimally. One of the major candidates that could have been involved here are structures called mitochondria,” said the clinical embryologist who performed the procedure, Jacques Cohen.
So Cohen transferred a donated cytoplasm to Sharon Saarinen's egg. This egg was then fertilised by her husband's sperm. "As a little bit of mitochondria was transferred, some DNA from the donor was in the embryo,” reports Pritchard at the BBC.
Seventeen babies were reported to be born at Cohen’s clinic using this procedure, including one that was miscarried and another that turned out to be twins. Cohen says that while the odds of one miscarriage occurring in this sample size reflected the rate seen in regular pregnancies, he did report his concerns. "This did worry us and we reported that in the literature and in our ethical and review board that oversees these procedures,” he told Pritchard.
The decision from the British Government on the legality of mitochondrial replacement is expected to be announced in the coming weeks.