GENE MUTATION RISK OF HIV CHILDREN
By Caroline Ryan
BBC News 16 Feb. 2002
Scientists in the US have confirmed that children born to HIV positive
mothers, exposed to treatment in the womb have an increased frequency of
So far, such combination therapies for HIV have been considered a
success, but there is some concern that potential risks for HIV positive
people who have children have not been assessed fully.
Experts already suspected that because the drugs act on the HIV viral
DNA, the foetus DNA could be affected if the woman was taking the drugs
while pregnant - potentially leading to cancers and other health
problems for the children in later life.
US researchers confirmed mutations were present, but said their work had
not shown cancers and health problems would definitely occur in the
children when they grew up.
Only monitoring children's health throughout their lives would provide
those answers, they said.
Pregnant HIV positive women are already warned of the potential risk to
their child's health from the therapies, and Dr Vernon Wilson, who
presented the work to the American Association for the Advancement of
Science annual meeting in Boston, said treatments should not be altered
in the light of his team's findings.
The study by his team at the Lovelace Respiratory Research Institute in
Albuquerque, New Mexico, looked at the antiviral drugs AZT and 3TC.
These are nucleoside reverse transcriptase inhibitors (NRTIs), the first
drugs given as HIV therapy and the most commonly used. They are commonly
combined with another type of drug called protease inhibitors in triple
The team looked at the umbilical cord blood cells of 51 children who had
been exposed to the NRTIs in the womb including AZT, and compared them
with 60 children in a control group.
The DNA of the children carries biological evidence if the children have
been exposed to AZT. The researchers looked at two particular so-called
marker genes, which the scientists used to check for DNA mutations.
It was found children exposed to both drugs had on average a two-fold
increased frequency of DNA mutations, but what those mutations might
mean for the children's health is not known.
Levels of AZT were higher in children who had been given a combination
of AZT and 3TC.
'No treatment change'
Dr Walker said the benefits of NRIT far outweighed the known risks to
children, but research looking at what happened to children with genetic
mutations had to take place.
He said more work was also needed to look at the genetic mutation risks
of different combination drug therapies.
"If the mother's health enabled you to use combinations that had less
risk for producing genetic mutations, you could use them during
pregnancy or at least during the last trimester."
Rochelle Diamond, chair of the National Organization of Gay and Lesbian
Scientists and Technical Professionals, is concerned that as HIV
positive people are living longer because of the therapies, more are
deciding to have children.
For this reason, she says more research needs to be done on the effect
of the drugs on children.
"It's one thing to take these wonderful drugs to treat a disease that is
really a death sentence for people if they don't treat it, but it's
another thing when they consider trying to have a child, and treat
themselves with these drugs which might hurt the children they are
trying to conceive."