Regulators consider radical biological procedures.
An advisory committee of the Food and Drug Administration is
holding meetings this week to consider radical biological procedures
that, if successful, would produce genetically modified human
This is a dangerous step. These techniques would change every
cell in the bodies of children born as a result of their use, and
these alterations would be passed down to future generations.
The F.D.A. calls them mitochondrial manipulation technologies.
The procedures involve removing the nuclear material either from the
egg or embryo of a woman with inheritable mitochondrial disease and
inserting it into a healthy egg or embryo of a donor whose own
nuclear material has been discarded. Any offspring would carry
genetic material from three people -- the nuclear DNA of the mother
and father, and the mitochondrial DNA of the donor.
Roughly 1,000 to 4,000 children born in the United States each
year will develop a mitochondrial disease, most by age 10, with
symptoms that can range from mild to devastating. These diseases
typically prevent mitochondria from converting food into energy and
are the result of genetic abnormalities, although some cases can be
caused by exposures to toxins. Disorders caused by mutations in the
mitochondrial DNA are passed down from the mother.
Developers of these modification techniques say they are a way
for women with mitochondrial disease to give birth to healthy
children to whom they are related genetically. Some are also
promoting their use for age-related infertility. These are worthy
goals. But these procedures are deeply problematic in terms of their
medical risks and societal implications. Will the child be born
healthy, or will the cellular disruptions created by this eggs-as-
Lego-pieces approach lead to problems later on? What about
subsequent generations? And how far will we go in our efforts to
These sorts of concerns were first voiced decades ago, well
before the human genome had even been "mapped." Those were the days
when our accelerating knowledge about genetics led to over-
optimistic hopes for quick fixes to an array of afflictions and
grandiose visions of designing genetically enhanced babies to be
more intelligent, athletic, musically talented and the like.
More recently, many scholars, scientists and policy makers have
urged a different approach: We should carefully and thoughtfully
apply the tools of human genetic engineering to treat medical
conditions in people, but we should not use them to manipulate the
genetic traits of future children. …