In-vitro fertilization linked to rare genetic disorders
REUTERS / Kacper Pempel
A doctor injects sperm directly into an egg during an in-vitro fertilization (IVF) procedure in Warsaw.
Sep 25, 2011 – 9:41 PM ET
A University of Toronto geneticist is calling for more study of a link between fertility treatment and certain rare genetic disorders, noting that babies born after treatment are up to 10 times more likely to suffer from the conditions — one of which causes serious mental disability.
And that is likely just the tip of the iceberg, Dr. Rosanna Weksberg said after addressing Canada’s fertility-medicine community recently.
Dr. Weksberg said she supports in-vitro fertilization and other reproductive-technology procedures, with the “wonderful” benefits they usually bring families, but noted that she is already seeing many fertility-treatment offspring with one of the conditions show up in her genetics clinic.
Dr. Weksberg said she supports in-vitro fertilization and other reproductive-technology procedures, with the “wonderful” benefits they usually bring families, but noted that she is already seeing many fertility-treatment offspring with one of the conditions show up in her genetics clinic.
Called Beckwith-Wiedemann syndrome, causing symptoms such as unevenly sized limbs, an enlarged tongue and a high risk of kidney tumours, it occurs in one of every 1,300 such children, compared to one in 13,000 in the general population.
Further research is required, said the physician at Toronto’s Hospital for Sick Children, to deduce why the treatments sometimes trigger genetic abnormalities — though still in a relatively small number of cases — and devise ways to make the treatments safer.
“We are seeing a significant increase in risk,” she said after her presentation to the Canadian Fertility and Andrology Society conference. “The most important message is … we need follow-up study.”
As she finished her talk, the fertility doctors and scientists politely applauded, filed out to their morning break and asked no questions, a contrast to previous speakers. The apparent lack of interest was “very telling,” Dr. Weksberg admitted with a smile later.
She said she would like to partner with one or more fertility clinics to study larger populations of children born with the help of reproductive technology, though so far has no takers.
She also said one of her “biggest disappointments” was that a Supreme Court of Canada ruling late last year had ruled unconstitutional most of the federal Assisted-human Reproduction Act, since the agency set up by the law could have played a key role in spearheading such research.
A spokesman for the fertility society said the industry is, in fact, keen to get to the bottom of genetic disorders connected to its work, but no clinic could afford to fund research on its own.
“It’s a very real source of concern,” said Dr. Roger Pierson, a University of Saskatchewan fertility scientist. “We’re still in the first two generations of people born with assisted-reproduction technology … and there is lots we don’t know about them.”
The genetic conditions detailed by Dr. Weksberg include not just Beckwith-Wiedemann, but also Angelman syndrome, which can cause serious mental retardation and speech impairment, and jumps from one in 15,000 births to one in 1,500 among fertility-treatment kids, she said.
There is also evidence of an increase in the likelihood of a baby being born at a low weight, and conflicting research suggesting an increased risk of autism, she said. Other findings may well come. “It’s the tip of the iceberg,” said Dr. Weksberg.
The exact cause of the genetic problems is unknown, but is likely a combination of the biological parents’ infertility problems and genetics, and the treatments themselves, said Dr. Weksberg.
Earlier, the conference heard from a U.S. scientist who told of new innovations in diagnosing genetic problems before in-vitro fertilization is performed, and in fetuses during pregnancy.
Dr. Matthew Rabinowitz, CEO of the company Gene Security Network and originally trained in physics and engineering, entered the field only a few years ago after witnessing a relative’s traumatic experience with a baby who was born with a genetic disorder and eventually died.
He said his analysis of the genetics of embryos, using results of the human-genome project, provide a more accurate prediction of problems like Down’s syndrome than conventional testing. Similar, non-invasive genetic testing is now also possible of fetuses during pregnancy by looking for fetal DNA in the mother’s blood, he said.
“This is something we really hope will change the practice of pregnancy management around the world,” said Dr. Rabinowitz, also a professor at Stanford University.
In fact, the work is of such innovation it could one day lead to a Nobel prize, predicted Dr. Pierson, calling it “brilliance beyond the norm.”
The research also raises moral and philosophical questions, though, since the testing potentially leads to the rejection of embryos for IVF or termination of pregnancies when genetic problems like Down’s are detected, he noted.
National Post
tblackwell@nationalpost.com
tblackwell@nationalpost.com
Entire article taken from the National Post.
