Alzheimer's mother gives birth to healthy baby

A woman set to develop Alzheimer’s disease has given birth to a healthy baby who is free of the debilitating illness, it has emerged.

The mother, who carries a genetic mutation which predisposes her to early-onset Alzheimer’s disease (AD) had the healthy child after receiving fertility treatment.

American researchers in Chicago, Illinois, tested her embryos so they could select and implant only those without the mutation.

It is believed to be the first time such a procedure has been successfully carried out.

However, because the woman is set to develop AD within the next 10 years she is unlikely to see the child grow up.

Details of the groundbreaking treatment were revealed in yesterday’s issue of the Journal of the American Medical Association (JAMA). However, the identity of the woman involved is being kept under wraps.

Dr Yury Verlinsky, of the Reproductive Genetics Institute in Chicago, and colleagues performed pre-implantation genetic diagnosis (PGD) on the woman.

The treatment is a combination of in vitro fertilisation (IVF) and DNA testing of embryos to allow the implantation of embryos free of genetic defects.

The research team writes: ‘‘This is the first known PGD procedure for inherited early-onset AD resulting in a clinical pregnancy and birth of a child free of inherited predisposition to early-onset AD.’’

The patient was a 30-year-old woman who did not actually have the symptoms of the illness but who carries a genetic mutation which develops into the disease as early as the mid or late 30s.

The mutation was identified in three of her five family members who were tested including the woman’s sister. She developed symptoms at the age of 38.

The authors believe the results demonstrate the feasibility of using the treatment for patients who want to avoid passing the mutant gene on to their children.

They write: ‘‘For some patients, this may be the only reason for undertaking pregnancy, since the pregnancy may be free of an inherited predisposition to AD from the onset.’’

However, some American academics have pointed out that the controversial study brings renewed concern to the whole issue of assisted reproduction.

They particularly take issue with the fact that the mother is likely to fall victim to the disease while the child is still very young. In a few years’ time she will probably not even be able to recognise the child.

Writing in today’s journal, Dena Towner and Roberta Springer Loewy, of the University of California, Davis, Sacramento, said: ‘‘The authors have provided a woman with the opportunity to have a child free of an inherited form of AD.

‘‘However, the mutation in her family confers onset of the disease during the fourth decade.

‘‘The woman was 30 years old when the procedure was performed, which means that she will likely manifest early symptoms of AD while this child is in the early, formative childhood years.’’

Drs Towner and Loewy stress that one of the first problems encountered by the patient’s sister once she developed AD was difficulty in caring for her two children.

Five years after the onset of symptoms this woman had been placed in an assisted living facility.

‘‘Much like her sister, the woman in the report by Verlinsky et al most likely will not be able to care for or even recognise her child in a few years,’’ they write.

They add: ‘‘This parent’s ethical responsibility can be interpreted in at least two ways.

‘‘One interpretation is that by resorting to selective preimplantation, the prospective parent was behaving in an ethically responsible manner by conceiving a child free of her own genetic predisposition for early-onset AD.

‘‘An alternative interpretation questions the purposive choice of bringing into the world a child for whom the mother will, with near certainty, be unable to provide care.’’