On May 7, 2016, St. Paul's Hospital's Pacific Adult Congenital Heart Disease (PACH) Clinic invited patients and their families to learn more about navigating life as an adult with congenital heart disease. Over 150 participants attended the clinic.

1. The Knowns and Unknowns: Genetic testing
and Congenital Heart Disease
Kirsten Bartels, MSc, CCGC
Genetic Counsellor
Heritable Aortopathies Clinic (Part of PACH clinic)
St. Paul’s Hospital
Unique Hearts, Unique Lives
07 May 2016

2. Let’s talk genetics.
• Genetics 101
– What is a gene?
– How do genes cause disease?
– How are genetic diseases inherited?
• Genetics of Heart Disease
– Genetic counselling
– Genetic testing and diagnosis

3. Genetics 101
What is a gene?
gene

4. Genetics 101
How do genes cause disease?
gene
X
X
X

5. Genetics 101
How are genetic diseases inherited?
Autosomal Dominant Autosomal Recessive

6. Genetics 101
How are genetic diseases inherited?
X‐linked recessive, fatherX‐linked recessive, mother

7. Genetics 101
How are genetic diseases inherited?
– Multifactorial (eg. isolated heart defects)
• (Usually) no genetic testing possible
• Recurrence risk based on study estimates
– Sporadic (eg. Down syndrome)

8. MYTH or FACT?
I look more like my dad, so I have more of his DNA and I
am more likely to develop his health problems down the
road.
ANSWER:
MYTH! We inherit 50% of our DNA from each parent,
regardless of which parent we physically resemble. It is
important to be aware of the family health history on both
sides of the family.

9. MYTH or FACT?
About 60% of humans DNA sequence is the same as
bananas.
ANSWER:
FACT! We share considerable similarities to many
different animals and plants, including bananas!

10. Genetics of Congenital Heart Disease

11. Heart Defects (isolated)
Tetralogy of Fallot, Ventricular Septal Defect, Coarctation of the Aorta, etc.
Heart Defects with other features
Down syndrome, Williams syndrome, 22q11 microdeletion, VATER,
CHARGE, etc.
Aortic disease and connective tissue disorders
Marfan, Familial aortic aneurysm, Ehlers‐Danlos, etc.
Heart Muscle Disease with other features
Noonan, Glycogen storage disease, Fabry disease, Amyloidosis, etc.
Heart Muscle Disease (isolated)
Hypertrophic CM, Dilated CM, Restrictive CM, Noncompaction CM,
ARVD/ARVC
Heart Rhythm Conditions
Long QT, Short QT, Brugada, CPVT

12. Genetic Counselling
Why did this occur?
Will it happen again in our family?
Who else is at risk?

13. • Specialized education
(medical genetics and counseling)
• Members of a healthcare team
• Information and support to individuals and families
at risk for, or diagnosed with, a variety of inherited
conditions
What is a Genetic Counsellor?

14. Genetic services in BC:
– Vancouver:
• Provincial Medical Genetics Program (BC Women’s)
• BC Inherited Arrhythmia Program (St. Paul’s Hosp/BCCH)
• Heritable Aortopathy Clinic (part of PACH clinic @ St. Paul’s Hosp)
• Hypertrophic Cardiomyopathy Clinic (St. Paul’s Hosp)
– Victoria
• Medical Genetics Clinic (Victoria General Hosp)

15. MYTH or FACT?
Genetic counsellors only meet with individuals who are
pregnant, or are planning a family.
ANSWER:
MYTH! Genetic counsellors meet with individuals who may
be at risk for genetic conditions at all stages of life.

16. MYTH or FACT? I have a family history of aortic aneurysm.
I can’t change my genetics so genetic counselling is not
important.
ANSWER:
MYTH! Genetic counselling can help you understand your
family history. For some people genetic testing can clarify
their chance of developing aortic disease… and how to find
it early!

17. MYTH or FACT?
I can see a genetic counsellor without having to undergo
extensive genetic testing.
ANSWER:
FACT! Genetic counsellors meet with patients who desire
a risk assessment regarding a particular heritable
condition. Testing is not always offered. However, even if
genetic testing is offered, it is up to the patient to decide
whether they would like to proceed.

18. Steve
Marfan Syndrome?
Connective Tissue Disorder?
Cardiologist
Nurse
Genetic Counsellor

19. Marfan syndrome
Genetic cause: FBN1 gene
Inheritance: Autosomal
dominant
• Congenital heart disease
– Aorta enlargement/aneurysm
– Aortic tear or rupture
– Mitral valve prolapse
• Bone overgrowth and joint laxity
– Scoliosis
• Ectopia lentis (lens dislocation)
Gene sequencing analysis
gene X

20. Steve
“Probable”
Marfan
syndrome
No family history
new daughter
Criteria

21. Why do genetic testing?
– Confirmation of diagnosis
– Guide treatment and management
– Screening tool for relatives
• Inheritance/recurrence risk
• Prenatal diagnosis
• Preimplantation genetic diagnosis

22. Genetic testing limitations
• Not available for all conditions
– Although the role of many genes is known and we can test for
many diseases, there is still a lot to learn
• Genetic testing does not detect 100% of disease causing
mutations
– In many cases, negative results would be considered
inconclusive and would not completely rule out a diagnosis
• Genetic information is not always straightforward in its
meaning
– Some results are subject to ambiguity and interpretation and are
not clear cut

23. Discrimination
Differential treatment of an asymptomatic person on the basis of
their genetic characteristics predicted from a genetic test result or
their family history
Historically, most accounts were based on anecdotal or unverified
data
www.ccgf‐cceg.ca (Canadian Coalition for Genetic Fairness)
www.genome.gov/10002077 (GINA, USA)

24. MYTH or FACT?
I don’t need Genetic Counselling regarding the disease in
my family as my mom went when I was young.
ANSWER:
MYTH! With changes in technology and knowledge, there
is often new information for families with genetic conditions.

25. Thank you!
Questions?
kirsten.bartels@vch.ca