Paris, Jan. 17 (AFP): Babies born through in-vitro fertilisation (IVF) may be prey to a rare genetic disorder, according to a study whose findings underscore the health perils from human cloning.
British researchers looked at the background of 149 babies with Beckwith-Wiedemann Syndrome, an inherited condition which causes excessive growth, low blood sugar, defects in the abdominal wall and kidney abnormalities.
Only about one per cent of the general population has the disorder.
But six of the 149 afflicted babies — four per cent — were born from IVF, the researchers said.
Three were born to the standard IVF method, in which an egg is fertilised by sperm in a lab dish, and the others to a technique called In Tracytoplasmic Injection (ICSI), in which sperm is directly injected in the egg.
The scientists, from the Universities of Birmingham and Cambridge, believe IVF disrupts “imprinting”, a process that occurs at the earliest stages of conception.
An embryo is a combination of a set of genes from its mother and a set of genes from its father.
Under imprinting, the activity of specific genes, from either the paternal or the maternal side, is muted during foetal development.
This way, there is no clash of competing genes, and the embryo develops normally.
“The genes themselves are not necessarily any different but imprinting controls how active the gene is,” said Wolf Reik, a co-author of the study released yesterday, who works at the Brabaham Institute in Cambridge.
“If the imprinting goes wrong, control is lost and this can result in unregulated growth,” he said.