Transcript Intro to Personal and Reproductive Genetics

Introduction to
Personal Genetics
Personal Genetics Education Project (pgEd)
Harvard Medical School - Wu Laboratory
www.pged.org
Do Now
Discuss with the following questions with the
people at your desk group:
1. What are the potential benefits to knowing more
about your genetic predisposition to (chance of
developing) a disease?
2. What are the possible downsides to knowing?
3. Aside from health and medical information, what
else might you be curious to learn about from
your DNA?
Genetics is getting more personal
because learning about our own
DNA is rapidly becoming
inexpensive and accessible.
DNA analysis can provide:
• Insights about our health, behavior, family history
and other traits.
• Highly personal information with personal, social
and familial impact.
• Information about genes and traits directly to
consumers.
Why might personal genetics matter to you?
“Under $1,000 dollars in this decade”
“Widely available in the next 5-10 years”
“Transforming health care for the next generation”
Photo: http://www.flickr.com/photos/jameshart/3216713992/sizes/s/in/photostream/
Quote sources: New York Times
The Beery twins’ story highlights the promise
of personalized medicine
http://the-scientist.com/author/lucy-reading/ (2011)
Personal choices based on
genetic information
• Angelina Jolie reveals
she chose to undergo a
double mastectomy.
• Jolie had a genetic test
and found she carried a
mutation in the BRCA1
gene. Doctors
estimated there was a
very high chance she
would get breast cancer.
Getty Images
Non-Invasive Prenatal Testing (NIPT)
• Fetus and mother
share a blood supply.
• Fetal cells release
DNA that enters the
maternal bloodstream.
• Maternal blood now
contains a mixture of
maternal cell-free
DNA and fetal cell-free
DNA.
http://www.monashultrasound.com.au/images/NIPT_clip_image003.jpg
“DNA tests locate genetic branches
of African American’s family trees”
http://www.post-gazette.com/stories/life/lifestyle/dna-tests-locate-geneticbranches-on-african-americans-family-trees-427734/
Photo credit: Steve Mellon
Genome sequencing technology
Applied Biosystems
3730 DNA Analyzers
Oxford Nanopore
MinION
2002
2014
http://www.flickr.com/photos/jurvetson/57080968/
https://www.nanoporetech.com
Direct-to-consumer analysis for sale
on the internet
The “lighter side” of DNA analysis
Health-related risks sold directly to consumers:
an evolving landscape
Challenges in personal genetics
1. Clinical utility: How likely is it you or your doctor can
take action based on genetic information?
2. How much might this information impact you and
your family?
3. How can we ensure access for everyone?
4. Will people understand that our environment (health
care, family, society, etc.) also shapes who we are?
Four Corners
activity
People should get counseling
from a doctor or genetic
counselor when they get
genetic testing because they
will not be able to handle the
information otherwise.
People should have the right
to learn whatever they want
about their DNA because it
is their own body.
I would only want to find out
my likelihood of developing
a disease if there are ways
to prevent or treat it.
Parents undergoing in vitro
fertilization should have the
option to screen embryos
for mutations likely to
cause a serious disease.
Parents should be able to
choose a child’s traits,
such as eye color and sex,
for non-medical reasons.
Employers should use
genetic information to make
hiring or firing decisions
about employees.
Parents should be able to find
out whatever they would like
about their children’s DNA
before they turn 18.
I would want to know if
someone I was dating had a
strong genetic predisposition
to a serious disease.
Genetics and reproduction
Personal Genetics Education Project (pgEd)
Harvard Medical School - Wu Laboratory
www.pged.org
Discussion questions:
• If you could choose specific traits or qualities
that you would want your child to have, what
would you choose? Why?
• Are there traits you would not want your child
to have? What are they? Why?
Genetic reproductive technologies
can be used to:
• Gain genetic information about an embryo or
unborn fetus.
• Help individuals conceive.
• Allow individuals to select embryos based on their
genetic makeup.
Prenatal testing
Invasive testing: Amniocentesis and chorionic villus sampling
Non-invasive prenatal testing
(NIPT)
•Fetus and mother
share a blood
supply.
•Fetal cells release
DNA, which can
then enter the
maternal blood
stream.
•Maternal blood now
contains a mixture
of fetal cell-free
DNA and maternal
cell-free DNA.
http://www.monashultrasound.com.au/images/NIPT_clip_image003.jpg
http://www.nature.com/news/researchers-turn-off-down-s-syndrome-genes-1.13406
What is in vitro fertilization (IVF)?
• In vitro fertilization is a technique used to treat infertility.
• A woman has eggs harvested from her ovaries, after
taking hormones to stimulate egg production. The eggs
are then combined with sperm in a petri dish.
• After 3-5 days, the embryos are assessed, and a
doctor/embryologist determines which embryos are of the
highest quality.
• One or more embryos are then placed in the woman’s
uterus. The embryo(s) may or may not attach and lead to
pregnancy.
What is preimplantation genetic
diagnosis (PGD)?
• The embryo is created via in vitro fertilization.
• Typically, a single cell is removed from the embryo at the
8-cell stage (3 days after fertilization).
• Genetic testing is performed.
• The results of testing are used to decide which embryos,
if any, to implant in the prospective mother’s uterus.
PGD:
Pre-implantation Genetic Diagnosis
Schwartz 2011
Jewish News
A Real Family impacted by PGD:
Molly and Adam Nash
Fanconi anemia (disorder of DNA repair)
Cure: PGD, umbilical cord blood
stem cells
http://tvnoviny.sk/sekcia/spravy/zahranicne/vo-francuzsku-sa-narodilo-prve-dizajnerske-dieta.html
What % of IVF clinics provide testing for the following reasons?
aneuploidy
autosomal disorders
chromosomal rearrangement
X-linked diseases
non-medical sex selection
avoid adult-onset disease
HLA typing
HLA typing w/o single gene test
Select for a disability
http://www.dnapolicy.org/resources/GeneticTestingofEmbryos.pdf
Public attitudes regarding acceptable uses of PGD:
Fatal
HLA match Adult
Sex Intelligence/
onset disease
strength
http://www.dnapolicy.org/resources/2006_Hudson_PGD_public_policy_and_public_attitudes.pdf
Opinion poll: What role, if any, should the
government of the United States play in
regulating PGD?
Want a total ban
on PGD
Support no
government
regulation
Think government
should regulate
ethics
only
Support
government
regulation of
safety and
quality
Believe
government
should regulate
safety, quality
and ethics
http://www.dnapolicy.org/resources/2006_Hudson_PGD_public_policy_and_public_attitudes.pdf
Discussion Questions
• What are the potential opportunities that PGD
can provide and what are the challenges of PGD?
• Now that you have discussed PGD, have you
changed your opinion about whether you would
want to choose certain traits for your child?
• If your parents had applied PGD to you, should
they tell you? Or would you prefer not to know?
• Do we need rules to guide how PGD is used? If
yes, what sort of rules? Whose job would it be to
make and enforce such rules?