A Baby, Please. Blond, Freckles — Hold the Colic

Laboratory Techniques That Screen for Diseases in Embryos Are Now Being Offered to Create Designer Children

By GAUTAM NAIK

Want a daughter with blond hair, green eyes and pale skin?

A Los Angeles clinic says it will soon help couples select both
gender and physical traits in a baby when they undergo a form of
fertility treatment. The clinic, Fertility Institutes, says it has
received “half a dozen” requests for the service, which is based on a
procedure called pre-implantation genetic diagnosis, or PGD.

While PGD has long been used for the medical purpose of
averting life-threatening diseases in children, the science behind it
has quietly progressed to the point that it could potentially be used
to create designer babies. It isn’t clear that Fertility Institutes can
yet deliver on its claims of trait selection. But the growth of PGD,
unfettered by any state or federal regulations in the U.S., has
accelerated genetic knowledge swiftly enough that pre-selecting
cosmetic traits in a baby is no longer the stuff of science fiction.

“It’s technically feasible and it can be done,” says Mark Hughes, a
pioneer of the PGD process and director of Genesis Genetics Institute,
a large fertility laboratory in Detroit. However, he adds that “no
legitimate lab would get into it and, if they did, they’d be
ostracized.”

But Fertility Institutes disagrees. “This is cosmetic medicine,”
says Jeff Steinberg, director of the clinic that is advertising gender
and physical trait selection on its Web site. “Others are frightened by
the criticism but we have no problems with it.”

PGD is a technique whereby a three-day-old embryo, consisting of
about six cells, is tested in a lab to see if it carries a particular
genetic disease. Embryos free of that disease are implanted in the
mother’s womb. Introduced in the 1990s, it has allowed thousands of
parents to avoid passing on deadly disorders to their children.

But PGD is starting to be used to target
less-serious disorders or certain characteristics — such as a baby’s
gender — that aren’t medical conditions. The next controversial step
is to select physical traits for cosmetic reasons.

“If we’re going to produce children who are claimed to be superior
because of their particular genes, we risk introducing new sources of
discrimination” in society, says Marcy Darnovsky, associate executive
director of the Center for Genetics and Society, a nonprofit public
interest group in Oakland, Calif. If people use the method to select
babies who are more likely to be tall, the thinking goes, then people
could effectively be enacting their biases against short people.

In a recent U.S. survey of 999 people who sought genetic counseling,
a majority said they supported prenatal genetic tests for the
elimination of certain serious diseases. The survey found that 56%
supported using them to counter blindness and 75% for mental
retardation.

More provocatively, about 10% of respondents said they would want
genetic testing for athletic ability, while another 10% voted for
improved height. Nearly 13% backed the approach to select for superior
intelligence, according to the survey conducted by researchers at the
New York University School of Medicine.

There are significant hurdles to any form of genetic enhancement.
Most human traits are controlled by multiple genetic factors, and
knowledge about their complex workings, though accelerating, is
incomplete. And traits such as athleticism and intelligence are
affected not just by DNA, but by environmental factors that cannot be
controlled in a lab.

While many countries have banned the use of PGD for gender
selection, it is permitted in the U.S. In 2006, a survey by the
Genetics and Public Policy Center at Johns Hopkins University found
that 42% of 137 PGD clinics offered a gender-selection service.

The science of PGD has steadily expanded its scope, often in
contentious ways. Embryo screening, for example, is sometimes used to
create a genetically matched “savior sibling” — a younger sister or
brother whose healthy cells can be harvested to treat an older sibling
with a serious illness.

It also is increasingly used to weed out embryos at risk of genetic
diseases — such as breast cancer — that could be treated, or that
might not strike a person later in life. In 2007, the Bridge Centre
fertility clinic in London screened embryos so that a baby wouldn’t
suffer from a serious squint that afflicted the father.

Instead of avoiding some conditions, the technique also may have
been used to select an embryo likely to have the same disease or
disability, such as deafness, that affects the parents. The Johns
Hopkins survey found that 3% of PGD clinics had provided this service,
sometimes described as “negative enhancement.” Groups who support this
approach argue, for example, that a deaf child born to a deaf couple is
better suited to participating in the parents’ shared culture. So far,
however, no single clinic has been publicly identified as offering this
service.

Like several genetic diseases, cosmetic traits are correlated with a
large number of DNA variations or markers — known as single nucleotide
polymorphisms, or SNPs — that work in combination. A new device called
the microarray, a small chip coated with DNA sequences, can
simultaneously analyze many more spots on the chromosomes.

In October 2007, scientists from deCode Genetics of Iceland
published a paper in Nature Genetics pinpointing various SNPs that
influence skin, eye and hair color, based on samples taken from people
in Iceland and the Netherlands. Along with related genes discovered
earlier, “the variants described in this report enable prediction of
pigmentation traits based upon an individual’s DNA,” the company said.
Such data, the researchers said, could be useful for teasing out the
biology of skin and eye disease and for forensic DNA analysis.

Kari Stefansson, chief executive of deCode, points out that such a
test will only provide a certain level of probability that a child will
have blond hair or green eyes, not an absolute guarantee. He says: “I
vehemently oppose the use of these discoveries for tailor-making
children.” In the long run, he adds, such a practice would “decrease
human diversity, and that’s dangerous.”

In theory, these data could be used to analyze the DNA of an embryo
and determine whether it was more likely to give rise to a baby of a
particular hair, skin or eye tint. (The test won’t work on other
ethnicities such as Asians or Africans because key pigmentation markers
for those groups haven’t yet been identified.)

For trait selection, a big hurdle is getting enough useful DNA
material from the embryo. In a typical PGD procedure, a single cell is
removed from a six-cell embryo and tested for the relevant genes or
SNPs. It’s relatively easy to check and eliminate diseases such as
cystic fibrosis that are linked to a single malfunctioning gene. But to
read the larger number of SNP markers associated with complex ailments
such as diabetes, or traits like hair color, there often isn’t enough
high-quality genetic material.

William Kearns, a medical geneticist and director of the Shady Grove
Center for Preimplantation Genetics in Rockville, Md., says he has made
headway in cracking the problem. In a presentation made at a November
meeting of the American Society of Human Genetics in Philadelphia, he
described how he had managed to amplify the DNA available from a single
embryonic cell to identify complex diseases and also certain physical
traits.

Of 42 embryos tested, Dr. Kearns said he had enough data to identify
SNPs that relate to northern European skin, hair and eye pigmentation
in 80% of the samples. (A patent for Dr. Kearn’s technique is pending;
the test data are unpublished and have yet to be reviewed by other
scientists.)

Dr. Kearns’ talk attracted the attention of Dr. Steinberg, the head
of Fertility Institutes, which already offers PGD for gender selection.
The clinic had hoped to collaborate with Dr. Kearns to offer trait
selection as well. In December, the clinic’s Web site announced that
couples who signed up for embryo screening would soon be able to make
“a pre-selected choice of gender, eye color, hair color and complexion,
along with screening for potentially lethal diseases.”

Dr. Kearns says he is firmly against the idea of using PGD to select
nonmedical traits. He plans to offer his PGD amplification technique to
fertility clinics for medical purposes such as screening for complex
disorders, but won’t let it be used for physical trait selection. “I’m
not going to do designer babies,” says Dr. Kearns. “I won’t sell my
soul for a dollar.” A spokeswoman for Dr. Steinberg said: “The
relationship between them is very amicable, and this center looks
forward to working with Dr. Kearns.”

For trait selection, Dr. Steinberg is now betting on a new approach
for screening embryos. It involves taking cells from an embryo at day
five of its development, compared with typical PGD, which uses cells
from day three. The method potentially allows more cells to be
obtained, leading to a more reliable diagnosis of the embryo.

Trait selection in babies “is a service,” says Dr. Steinberg. “We intend to offer it soon.”

Write to Gautam Naik at gautam.naik@wsj.com