09.05-09.35 NVVC 2016 Wilde..key


DNA diagnostiek, alles bij iedereen?
NVVC voorjaarsvergadering 2016, 31 maart
Arthur AM Wilde
Disclosure belangen spreker
(potentiële) belangenverstrengeling
Geen
Disease (arrhythmias, cardiomyopathy)
Gene
Heart Centre
Disease (arrhythmias, cardiomyopathy)
Gene
Protein structure/function
Celbiology/physiology
gene specific therapy
new therapy
Organ biology
Heart Centre
new therapy, gene specific therapy
New therapy
♥ Flecainide in CPVT (RyR2 blocker)
♥ yet to follow
Gene specific therapy
♥ Long QT Syndrome
♥ LMNA, PLN, DPP6
Heart Centre
Disease (arrhythmias, cardiomyopathy)
Gene
Prediction/prevention
Protein structure/function
Celbiology/physiology
gene specific therapy
new therapy
Organ biology
Heart Centre
Genetic couselling AMC
AMC
Heart Centre
Genetic couselling AMC
AMC
Heart Centre
Heart Centre
Yield of molecular diagnosis in primary
electrical heart disease
142/281
LQTS
19/47
CPVT
BrS
68/244
0
25
50
75
100
Heart Centre
%
Yield of molecular diagnosis in cardiomyopathies
300/648
HCM
48/219
DCM
%
96/246
ARVC
0
25
50
75
100
Heart Centre
Heart Centre
Does cascade screening lead to treatment?
A follow-up study in 442 presympt. screened family members
%
%
Treated
FU: 3-4 y
LQTS (282) CPVT (107)
Hofman et al, JACC 2010;55:2579-6.
BrS (53)
Heart Centre
Does cascade screening lead to treatment?
A follow-up study in 442 presympt. screened family members
%
%
Treated
FU: 3-4 y
LQTS (282) CPVT (107)
Hofman et al, JACC 2010;55:2579-6.
BrS (53)
Heart Centre
Genetic testing in Cardiology (>1995)
Historical development
♥ Targeted gene screening, gene by gene
♥ Small panels
♥ Large panels
♥ Whole exome sequencing
♥ Whole genome sequencing
Heart Centre
Genetic testing in Cardiology (>1995)
Arrhythmias and Cardiomyop.
♥ <1995: no testing possible
♥ 1995-2012: single genes
Heart Centre
Heart Centre
LQTS, genetic testing
40 referred unrelated patients
31 (78%) with mutations, 3 double mutation
♥ Type 1
KCNQ1
9
29%
♥ Type 2
KCNH2
18
58%
♥ Type 3
SCN5a
4
13%
Prospective prediction of the genotype
Van Langen et al., J Med Gen 2003;40:141-5
Heart Centre
%
18/31
Correct prediction
Van Langen et al., J Med Gen 2003;40:141-5
Heart Centre
28/31
%
23/31
18/31
Correct prediction
Van Langen et al., J Med Gen 2003;40:141-5
Heart Centre
Genetic testing in Cardiology (>1995)
Arrhythmias and Cardiomyop.
♥ <1995: no testing possible
♥ 1995-2012: single genes
♥ 2012-2014: panels
♥ >2014: exome seq, WGS
Heart Centre
23
Genetic testing in Cardiology (2015)
Whole exome sequencing, WGS
♥ Complex syndromic children
♥ not fitting in one syndrome
♥ Potential to identify multiple syn.
Heart Centre
2014
Cardio-panel v1; 48 genes
Hum Mutat 2013;34:1035-1042
99% of all bases of the target genes is of high quality
No false positives; no false negatives
12-16 patients can be multiplexed
Average coverage: >200x (currently ~400x)
~15 exons require Sanger sequencing in parallel
Cardiomyopathy panels: some
examples
No Genes
price
TAT
46-60
€2200
120 days
Blueprint Genet 102
€1400
21 days
Harvard
62
$?
70 days
GeneDx
72
$?
70 days
Health-in-Code
112
€1750
?
NL health care
Results AMC
2014-2015 BrS genetic testing
♥ 46 patients tested
♥ 21 no mutation
♥ Identified variants: - 3x SCN5a (class 5)
- 2x SCN5a (class 4)
- 15x variants other genes
- all class 3
Heart Centre
“Mutation calling”
The archillesheel of genetic
testing!
Heart Centre
LQTS, Genetic testing
When is a mutation causal?
♥ with strong segregation
♥ prevalence < 1%
♥ well conserved within species
♥ well conserved in its “class”
♥ with presumed functional effects
♥ with measured functional effects
Heart Centre
LQTS, Genetic testing
When is a mutation causal?
♥ with strong segregation
♥ prevalence < 1%
♥ well conserved within species
♥ well conserved in its “class”
♥ with presumed functional effects
♥ with measured functional effects
Heart Centre
Heart Centre
Genetic
Testing
for LQTS
Patients
LQTS
Variants
in Health
LQT1
LQT2
LQTS
Slide courtesy of Ackerman
C1159
• 4% Background Rate in Healthy Caucasians
• 6-8%
Background
in Healthy
Non-Caucasians
Exercise
Extreme
Caution
When Calling
Mutations
LQT3 Rate
LQTS
Mayo Variants
Clinic 541
in
Health
Series of LQTS
Ackerman
et al. Mayo Clin
referrals
Proc
78:1479-1487,
2003
Tester
… Ackerman.
Ackerman
et al.2:507-517,
Heart
Heart Rhythm
Rhythm
2005 1:600-607, 2004
Slide courtesy of Ackerman
Rare Variants Localizing Here Have
Only a 25 – 50%
Estimated Predictive Value
for Pathogenicity Versus
“Background Genetic Noise”
World
Wide
Brugada
Syndrome
Consortium.
Heart
Rhythm 1:33-46,
2010
Kappa,
Tester
……
Wilde,
Ackerman.
120:1752-1760,
Kapplinger
Ackerman.
HeartCirculation
Rhythm
6:1297-1303,
20092009
Genetic tests are NOT
binary (yes or no) tests,
but are fundamentally
probabilistic in nature!
Slide courtesy of Ackerman
... calling mutations ...
The archillesheel of
genetic testing!
will get worse with more extensive
genotyping (NGS)
Heart Failure Research Centre
Medically actionable variants
57 genes, 29 cardiac phenotype
2013
Medically actionable variants
N=16 (6.5%)
Case Presentation
39
+
34
Ackerman. Heart Rhythm 2015
Genetic Purgatory Can Be
Dangerous
L537P
VUS
Ackerman. Heart Rhythm 2015
Case Presentation
39
+
-
34
-
+ + +
+ = L537P-SCN5A = BrS1
Ackerman. Heart Rhythm 2015
JAMA 2016
JAMA 2016
♥ study within eMERGE-PGx project
♥ 2022 ind. (2012/10 - 2013/10), 7 sites
♥ sequence data, pharmacogenes (n=84)
♥ and EMR data
♥ data reported on SCN5a and KCNH2
JAMA 2016
no consensus in experienced laboratories
on the vast majority of variants (in SCN5a
and KCNH2) identified in an unselected
population
“Mutation calling”
The archillesheel of genetic
testing!
How to proceed?
Heart Centre
Data sharing: national slow/fast
ClinGen: sharing data
Disease (arrhythmias, cardiomyopathy)
Gene
Prediction/prevention
A good example where genetics entered our field
Heart Centre
Sudden death in families
Pedigree one of the families (2004)
USD 48
USD 31
Heart Centre
Sudden death in families
Pedigree one of the families (2006)
Pedigree one of the families (2006)
USD 48
IVF 44
USD 31
USD 31
IVF 16
Heart Centre
Heart Centre
Sudden death in families
Risk stratification
♥ Hypertrophic cardiomyopathy
- among others septum thickness
♥ Long QT syndrome
- QTc interval
♥ Idiopathic ventricular fibrillation
- no phenotype, risk stratification impossible
Heart Centre
Sudden death in families
Pedigree one of the families (2006)
Pedigree one of the families (2006)
USD 48
IVF 44
USD 31
IVF 16
USD 31
ICD
Heart Centre
Haplotype sharing analysis: 7q36
Alders et al. Am J Hum Genet 2009
Modifier of the transient outward current
Particularly so in Purkinje fibers
Instable P-fiber electrical activity
Short coupled extra’s with immediate onset VF
DPP6
Heart Centre
Sudden death in families
Pedigree one of the families (2006)
Pedigree one of the families (2006)
USD 48
IVF 44
USD 31
IVF 16
USD 31
ICD
Heart Centre
ten Sande et al. Heart Rhythm 2016
Heart Centre
♥ 76 ICD implants (primary prevention), 2 appropriate shocks FU 5±3 years
ten Sande et al. Heart Rhythm 2016
Heart Centre
Genetic testing, where to go?
Next gen sequencing
♥ Maybe too early?
♥ Cannot be stopped
♥ Mutation calling!
♥ Keep it in experienced hands
Heart Centre
Dank U wel
Heart Failure Research Centre