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Dec 14, 2012 (4 years and 8 months ago)

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Genetic Engineering:
Designer Babies

By: Jennifer Van

JV

What are Designer Babies?


Refers to genetic interventions into pre
-
implantation embryos in the attempt to influence
the traits that the resulting offspring will have


Term used by journalists, not scientists


More realistic term: “Selected Baby”


Currently not attainable, however advanced
technologies can be used to select the sex of your
future offspring as well as the ability to screen for
certain genetic defects (only legal in certain
countries)


Designer Babies

Pros


Enable parents to avoid the
hardships and economic
burdens that accompany the
birth of a child with an
incurable disease


New & Better genes passed
on to others


Ability to enhance muscles,
height, intelligence


To choose the sex, hair colour
and even personality of our
children


Cons


Demeans the uniqueness
of each individual
therefore undermining
humanity


Provides those with an
unfair competitive
advantage over the un
-
enhanced


Widens the existing social
gap between those who
can and cannot afford the
new treatment

Pre
-
Implantation Genetic
Diagnosis (PGD)


An
in vitro fertilization technique
in
which
embryos (an unborn offspring
in the process of development)
are
created outside the womb and can
then be tested for genetic disorders
and
gender


Unfertilized eggs will be removed
from the patient, fertilized in a petri
dish and then brought to a zygote
(eight
-
cell) stage at which point cells
are removed and then tested using
PGD


Reduces the chances that a child will
be born with a genetic disorder



Using PGD for Sex Selection


The researchers at the Genetics & IVF Institute in
Fairfax took advantage of a simple rule in biology:
girls have two X chromosomes whereas boys have
one X and one Y chromosome


In order to choose the sex of the offspring, the
power lies within the father’s sperm


Y chromosomes have less DNA than X’s


So, by staining the sperm’s DNA with a nontoxic
light
-
sensitive dye, the Virginia scientists were able
to sort sperm by gender with a high rate of success


Screening for Genetic
Defects with PGD


Only specific disorders can be tested for, there is no generic test
available as a “catch
-
all”


It is necessary for a disorder to be pre
-
identified i.e., it’s known
that parents are likely to pass on the disorder or disease to their
offspring


Polymerase chain reaction is used on single cells to identify
disorders such as: B
-
Thalassaemia
, Li
Fraumeni

syndrome, cystic
fibrosis,
Duchenne

muscular dystrophy (X
-
linked recessive trait
that weakens the muscles), and
etc


http://
individual.utoronto.ca/kevinkuo/GATTACA/Harper
-
PGD.pdf



In brief, a polar body or a
blastomere

is placed
in a solution that
lyses the cell
and releases
the
DNA



A PCR reaction mix
is then added and PCR begins


The Nash Family


Lisa and Jack Nash are carriers for
Fanconi

anemia, a genetic disorder
leaving them with a 1 in 4 chance of having an affected child


They had a 6 year old daughter (Molly) who was born with a rare
genetic bone marrow disease that would kill her unless she received a
transplant from someone with an identical tissue type


Nash’s elected 15 embryos and subject them to PGD


A single cell was taken from each embryo and tested for genetic
mutation that causes
Fanconi

anemia


They went a step further to check for which one carried a tissue type
that matched their daughter


In August 2000, Adam Nash was born and doctors in Minnesota
performed a stem cell transplant on Molly using blood taken at birth
from Adam’s umbilical cord and his bone marrow


Both children are healthy

Marathon Mice


In August 2004, scientists in
California announced the birth of
“Marathon Mice”


A new breed of genetically
-
modified mice that gained muscles
and endurance without any
exercise and never became obese


Most test subjects did not survive
due to immune responses to the
injected foreign DNA


Therapy fails to meet rigors of
human safety, efficacy and
protection therefore not approved
for human use

ANDi



On January 11, 2001, scientists in
Oregon unveiled
ANDi

(inserted DNA
spelt backwards), a baby rhesus
monkey containing a new jellyfish
gene in his genome


The jellyfish gene green fluorescent
protein was used as it is easily
detectable under a microscope


However, when tissue samples were
taken, they did not glow and the
green fluorescent protein was not
detectable


"Maybe the quantity of protein is
too small to be seen or maybe the
mRNA is not being translated," says
Anthony Chan



Even though the GFP gene did
not work, it shows that for the
first time it is possible to
change the genetic make
-
up
of a primate by inserting a
gene into the egg

Creating
ANDi


To create
ANDi
, Chan and his colleagues
injected 224 unfertilized rhesus eggs with a
virus carrying the GFP gene


The virus's job is to integrate the gene into
a random site on one of the chromosomes


Six hours later, each egg was artificially
fertilized by sperm injection


Roughly half of the fertilized eggs grew
and divided, reaching the four
-
cell stage


Forty were chosen and implanted into
twenty surrogate mothers

two per
mother


Of these, three healthy males were born
and two twin males were stillborn


ANDi

was the only live monkey carrying the
GFP gene


Statistics


In 1985, there were 30 fertility clinics in the U.S.


Ten years later, there were more than 300


More than one million couples seek fertility treatment
each year and spend more than 3 bill in pursuit of babies


Fees for IVF vary between $5000
-

$15,000 with another
$2
-
3 thousand for fertility drugs


PGD adds several thousand dollars


Clinic success rates improved from 17% in 1992 for women
under 40 to nearly 30% in 1999


Success rates vary wildly from 14% to as high as 60%

Statistics


Since 1980, according to the National Center for health statistics the
number of twins born per year has risen 67%


The rate of triplets and higher
-
order birth multiples has soared from
37 per
100,000
live births in 1980 to 184 per 100 000 in 1999


In
2001, the American Society for Reproductive Medicine
recommended transferring at most 2 embryos to the mothers
womb for younger patients while older women can
recieve

as many
as 5


PGD is legal in the U.S. and Australia, but illegal in the United
Kingdom (unless used for genetic disorders), Denmark, Italy,
Portugal, Spain, New Zealand, and Germany


Engaging
in
PGD or
embryo selection in
order to implant embryos of
a particular gender (except for the purpose of preventing,
diagnosing or treating a sex
-
linked disease) is a criminal act carrying
with it the penalty of up to ten years in jail and/or a $500,000
fine in
Canada

Future Outlook


Scientists will need to do a lot more work on identifying and
isolating the specific genes that control the growth and
development of each individual feature, trait, characteristic
or talent


They will need to work out how to alter the DNA so that the
child will match with the parent’s request


The formation of the human is a highly complex process of
interaction & interweaving


It is possible to imagine a society where children can be
bred for specific purposes like off planet living where
genetic manipulation is essential for survival


References


(2002). In
BIONET
. Retrieved May 15, 2012,
from

http
://
www.bionetonline.org/English/Content/db_cont1.htm


Brownlee, S. (2002, March). Designer Babies.
Washington Monthly, 34(3
). Retrieved

May
5, 2012, from the EBSCO
database


Chan, A. W. S.
et al.
Transgenic monkeys produced by retroviral gene transfer into

mature oocytes.
Science

291, 309
-
312 (January 12, 2000).


Genetic Engineering
-

Designer Babies. (2010). In
Future Human Evolution
.

Retrieved
May 7, 2012,
from

http
://www.humansfuture.org/genetic_engineering_designer_babies
.

php.htm


Lemonick
, M. D. (1999, January 11). Designer Babies.
Time Magazine
.
Retrieved
May 15,

2012
,
from
http
://
www.ecasd.k12.wi.us/faculty/dsampson/designer%203.pdf


Ren
, Y. (2005). Designer Babies: The Pros and Cons of Genetic Engineering.

Massachusetts
Institute of
Technology
Undergraduate Research Journal
,
12
, 28
-
32.

Retrieved
May 15, 2012, from
http
://
web.mit.edu/murj/www/v12/v12
-

Features/v12
-
f4.pdf


Steinbock
, B. (2008, October 11). Designer babies: choosing our children's genes.
The

Lancet
,
372
(9646
),
1294
-
1295.
doi:10.1016/S0140
-
6736(08)61345
-
8

Picture References


http://www.inquisitr.com/199639/ethicists
-
say
-
killing
-
babies
-
should
-
be
-
legal
-
draw
-
controversy
/



http://
news.bbc.co.uk/2/hi/science/nature/3592976.stm



http://
www.wired.com/science/discoveries/news/2001/01/41131



http://
homepage.smc.edu/hodson_kent/Gene_Engineering/Ethics/bone
_mar.htm


http://www.theglobeandmail.com/life/parenting/pregnancy/pregnancy
-
trends/the
-
price
-
of
-
embryo
-
screening/article2294658
/



http://www.scq.ubc.ca/preimplantation
-
genetic
-
diagnosis
-
and
-
our
-
future
-
should
-
we
-
be
-
peering
-
into
-
the
-
womb
/