3. 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.
5. 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
6. Public attitudes regarding acceptable uses of PGD:
Fatal HLA match Adult
onset disease
Sex Intelligence/
strength
http://www.dnapolicy.org/resources/2006_Hudson_PGD_public_policy_and_public_attitudes.pdf
7. Egg Sperm
Remove one cell
On day 3rd
Embryo 8 cell stage
Test DNA or
chromosomes
Test results
Healthy
gen
conditions
Unhealthy
gen
conditions
Embryo
implanted on day
4
Embryo
discarded
8. Preimplantation Genetic Diagnosis
(PGD)
PGD is a state-of-the-art
procedure used in
conjunction with In Vitro
Fertilization (IVF)
in which the embryo is
tested for certain conditions
prior to being placed in the
womb of the woman.
PGD was first reported in
1990.
PGD combines the recent
advances in molecular
genetics and in assisted
reproductive technology
9. Indications for PGDChromosomal Disorders
Chromosomal
rearrangements
Inversions
Translocations
Chromosome Deletions
Gender determination for severe X-
linked diseases
Severe monogenic diseases (cystic
fibrosis, ß thalassaemia, sickle cell
anemia, fragile X syndrome,
myopathies)
Recurrent pregnancy loss
Advanced Maternal Age
Couples with >3 IVF failures
Epididymal or Testicular sperm
aspiration with >1 IVF failures.
10. Benefits of PGD
Increased Implantation
Rate
Reduction in Pregnancy
Losses
Reduction in the Chance
of Having a Child with
Aneuploidy
.Reduces the possibility
of having to choose to
terminate the pregnancy
following a diagnosis of a
probable genetic disorder.
14. PGD TimeLine
1970 1980 1990 2000 2010
Implementation of
the FISH into the
cytogenetics
First PCR - PGD
FISH – sex
selection
Implementation of the CGH
into the cytogenetics
arrayCGH reported for clinical genetics
CGH-
PGD
aCGH-
PGD
PCR -PGD for Fresh
ET
SNP-
array
PGD
First delivery
after aCGH-
PGS
aCG
HFirst aCGH-
delivery
15. What? Where? and When?
15
• PB 1 & 2
• Blastomere (cleavage stage -day 3)
• Trophectoderm (blastocyst – day 5)
Features
PB biopsy Blastomere biopsy TE biopsy
•Indirect data about the
oocyte genotype
•Male factor is not taken
into account
•Mosaicism is not excluded
•Decreasing the embryo
viability
•Subsequent self-correction
of trisomic embryos is not
excluded
•More cells = more DNA = more
accurate diagnostics
•Less mosaicism
•Reduced impact of embryo
biopsy
•Economic factor: less embryos
to be analized
•Facilitates the selective
embryo transfer
•Allows to modify endometrium
if needed
•Ability to blastocyst cultivation
and vitrification are needed
17. Overview For setting up a PGD
center
Setting up a PGD Centre
Organisation of the PGD Centre
Preparation for clinical PGD
Misdiagnosis
Accreditation
External quality assessment
ESHRE PGD Consortium
Future of PGD/PGS
What makes a good PGD Centre?
18. Setting up a PGD centre
Two ways
IVF centre and PGD centre in the same
institute – preferred
Transport PGD
19. Organisation of the PGD Centre
Highly successful IVF unit
Patients need genetic and specific PGD
counselling
Biopsy performed by trained embryologist
Diagnosis performed by molecular
biologist/cytogeneticist
Accredited lab
Patient information leaflets and consents
Excellent communication between IVF centre
and diagnosis lab
Join the PGD Consortium
20. Pretreatment workup
FISH
Sexing need to check for polymorphisms
Translocation protocols developed by cytogeneticist
For PGS – polymorphic sites
PCR
Confirmation of mutation on proband and relatives
Suitable informative markers to detect
contamination
Experienced molecular biologist
Arrays
Depends on if for molecular or cytogenetic
Validation of WGA and array
Experienced clinical scientist
21. Workup of diagnosis
Validation of method
Full authorised report
Protocol logged into lab system
Prior to cycle – internal quality
assessment of all reagents and
equipment
22. Clinical cycle
Full consultation, information leaflets, relevant
consents
Need good number oocytes/embryos
Patients must not have unprotected sex
All cumulus cells removed (maternal contamination)
ICSI for all molecular diagnosis (paternal
contamination)
Medium to support blastocyst growth
Clear identification of biopsied cell and embryo
number
Ensure correct embryo transferred
Appropriate witnesses throughout diagnosis
Full authorised report logged in PGD and IVF centre
23. Key points for biopsy/diagnosis
lab
Counselling
Appropriately trained staff
Aware of misdiagnosis possibilities
Quality control
Records
ISO/accreditation
24. Accreditation
ISO 15189
Every country has national body
How can we help?
QM workshop
Paper on accreditation of a PGD
laboratory, Harper et al, 2010
Establish an accreditation advisory panel
Discussion with national accreditation
bodies
Offer centres help with accreditation
process
25. ISO 15189
•Management requirements
Organization and quality management
Quality management system
Document control
Review of contracts
Examination by referral laboratories
External services and supplies
Advisory services
Resolution of complaints
Identification of control of non conformities
Corrective action/Preventative action
Continual improvement
Quality and technical records
Internal audits
Management review
27. What makes a good PGD
centre?
COMMUNICATION
Excellent IVF Platform
Excellent Diagnostics Laboratory
Integration of Services
Rigorous Quality Control/Quality
Assurance
Commitment to Follow-up
Comprehensive Ethical Review
TRANSPORT PGD
28. • Gain genetic information about an embryo or
unborn fetus.
• Help individuals conceive.
• Allow individuals to select embryos based on their
genetic makeup.
Genetic reproductive technologies
can be used to:
29. Future of PGDEfforts continue to be
focused on improving
methods to obtain an
accurate diagnosis.
PGD holds great
promise for the future as
techniques and genetic
tests are perfected.
PGD may become
routine in the next few
years.
30. It’s hard to being a good
embryo
30
But even more difficult to detect
it…