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COAGULATION CONFERENCE MEXICO CITY 2013
1. Lessons from Genome-Wide Association Studies
in Venous Thrombosis
NOTE: VIEW ON FULL SCREEN
Raul A. DeLa Cadena, M.D.
Temple University School of Medicine
Philadelphia, Pennsylvania
“La Mujer” David Alfaro Siqueiros 1964-1971
3. GWAS and Venous Thrombosis
• The revolution started with:
– Human Genome
– HapMap projects
Lander ES, et al.: Nature, 2001
Venter JC, et al.: Science, 2001
5. • Until the end of the 20th Century: Association
and linkage studies.
• Compared to the number of studies
performed, successes in VT were relatively
modest despite notable discoveries.
• SERPINC1, PROC, and PROS1..
– Association with VT over 25 years.
• F5, F2, ABO y FGG
– More frequent SNPs and associated with VT.
Risk Factors Known prior to
GWAS Era
6. F5 Gene
• Rs6025
• Factor V Leyden
• R506Q
• Resistence activated Proteina C
• Allele Q506 has a frequency of 5% in
Caucassians with an increased risk of about 3
times compared to heterozygous carriers
Bertina RM, et al.: Nature 1994
Seligson U, et al.: N Engl J Med 2001
7. F2 Gene
• Rs1799963-A
• 20210
• G20210A
• Elevated plasma levels of FII
• Allele G20210A associated with an increased
risk of about 2.5 times when compared with
heterozygous carriers
Poort SR, et al.: Blood 1996
Seligson U, et al.: N Engl J Med 2001
8. Gene FGG
• Rs2066865.
• Frequency of approximately 25%.
• Modulating the levels of a form of fibrinogen
in plasma by affecting a polyadenation site.
Tregouet DA, et al.: Blood, 2009
9. ABO Blood Groups
• A1
• B
• Associated with VT apparently by increased
levels of plasma FVIII y vWF due to decrease
clearance but not clearly determined today.
• Associated frequency of about 30%
Wu O, et al.: J Thromb Haemost 2008
11. New Risk Factors from the GWAS Era
• First study conducted by Bezemer et al.
– 200,000 SNPs.
– DNA analysis performed in group and individually.
– Two novel susceptibility loci identified: GPVI y F11
• Second study concentrated in approximately
300,000 SNPs.
– No new susceptibility loci for VT identified, but strong
associations were observed at two known loci, the FV and
the ABO genes.
Bezemer ID, et al.: JAMA 2008
Tregouet DA, et al.: Blood, 2009
12. GP6
• Allele rs1613662-G
• Confirmed by three other studies.
• Substitution A/G, amino acid 219, exon 4,
gene coding for GP6: isoforms GPVIa y GPVIb.
• GPVI for collagen in platelets
Bezemer ID, et al.: JAMA 2008
Snoep JD, et al.: J Thromb Haemost, 2010
13. F11
• Alleles rs2289252 y rs2036914
• Additive effect regulating the plasma levels of
FXI.
Bezemer ID, et al.: JAMA 2008
Meijers JC, et al.: N Engl J Med, 2000
14. New Susceptibility Locus on
Chromosome 6p24.1
• Allele rs169713
• Allele lies about 100kb downstream of the
HIVEP1 gene. It belongs to a family of genes
participating in transcriptional regulation of a
variety of inflammatory genes.
Morange PE, et al.: Am J Hum Genet, 2010
15. GWAS contribution in the
understanding of shorthened aPTT
• Short aPTT, a laboratory tool, due to is
association with VT.
• A study with 1477 normal subjects with the
identification of 3 SNPs
– Rs27431672 (F12)
– Rs9898 (HRG)
– Rs710446 (KNG1)
Tripodi A, et al.: Blood, 2004
Houlihan LM, et al.: Am J Hum Genet, 2010
16. F12, HRG, KNG1
Association con Thrombosis
• Study with 1,542 patients with VT and 1,110
normal controls.
• The rs710446 (KNG1) was found associated
with a risk for thrombosis.
• Confirmed with another study with 596
patients and 590 normal controls.
• Rs710446 (KNG1), consists of a single amino
acid substitution (Ile581Thr) in KNG1 (HK).
Morange PE, et al.: Blood, 2011
19. Additional Information from GWAS
• Some GWAS) studies were conducted within the context of the
pathophysiology of VT and instead of VT risk assessment.
• One of them evaluated SNPs to study the variation of Protein C in plasma.
• Conducted with 8,000 participants identified 5 genes.
– PROCR which codes for the Proteina C receptor identified rs867186 explaining
about 10% of Protein C variability in plasma. It is associated with an increased
susceptibility of the receptor to proteolysis and thus associated with an
increased risk to VT.
• Additional genes were identified, namely EDEM2, BAZIB, y GCKR requiring
careful attention for their association with VT.
– GCKR gene plays a major role in the levels of reactive C protein, in favor of the
known association between inflammation and coagulation.
Dehghan A, et al.: Circulation, 2011
23. Normal Endothelium
NO PGI2 ADPase
Heparan
+
ATIII
Inhibition FXa + Trombin
tPA
uPA
Plasmin Plasminogen
Trombomodulin
Protein C Protein Ca
Protein S
Trombin
FVa
FVIIIa
Platelet Inhibition
PAI
PROC
PROS1
26. A 46-year old man admitted to ER with:
1. Chest pain
2. Diaphoresis
History, mild smoker.
1. Anxious
2. Hypotensive (70/50 mm Hg
3. EKG:
• Bradycardia
• Prolongation QRS complex
• Total AV block
• ST elevation
Troponin I 15.1 ng/ml (reference range <0.01 ng/ml)
Diagnosis of acute myocardial infarction complicated with
cardiogenic shock and total AV block was made.
Case Report
27. Coronary Angiogram
Normal right and circumflex coronary artery and a noncritical plaque in
Left anterior descending artery.
During coronary angiography chest pain was resolved abruptly and
Electrocardiographic changes dissapeared.
Patient transferred to ICU. After administration of heparin and aspirin
Transthoracic echocardiography was performed.
• Suspicion of a mass placed in noncoronary sinus of Valsalva
Transesophageal echocardiography was performed.
29. •A round mass (25 x 10mm) filling the
noncoronary sinus of Valsalva.
•The mass was highly mobile and
prolapsing into right coronary artery
ostium intermittently.
Transesophageal
Echocardiography
30. Platelet count - Normal
AT-III - Normal
Protein S - Normal
Protein C - Normal
Factor V Leiden - Normal
Prothrombin - Normal
Factor XII - Normal
Methyltetrahydrofolate (MTHFR) - Normal
SPECIALIZED COAGULATION LABORATORY
31. Surgical Procedure
Emergency surgery, a solid round mass
25mm diameter occupying the
Noncoronary sinus of Valsalva was seen
and removed.
Mass penetrated into the right coronary
artery ostium.
32. Normal Endothelium
NO PGI2 ADPase
Heparan
+
ATIII
Inhibition FXa + Trombina
tPA
uPA
Plasmin Plasminogen
Trombomodulina
Proteina C Proteina Ca
Proteina S
Trombina
FVa
FVIIIa
Inibicion Plaquetas
PAI
PROC
PROS1
Homozygote
Rs1799768
PAI-1 G4/G5
33. What to do now?
Homozygote
Rs1799768
PAI-1 G4/G5
34. Conclusions
• GWAS, require a large number of participants, for instance, to
identify 10 SNPs associated with cardiovascular disease, over
140,000 subjects needed to be included.
• Noteworthy to mention is that a gene housing a rare mutation
associated with VT may house SNPs with a moderate risk of
thrombosis.
• For instance by the use of the deep gene analysis method like
the one use for F9 a rare mutation was found (R338L)
associated with elevated numbers of FIXa and thrombotic
events in young adults which is expressed in other family
members and known as FIX Padua.
Schunkert H, et al.: Nat Genet 2011
Simioni P, et al.: N Engl J Med, 2009
35. Lessons from Genome-Wide Association Studies
in Venous Thrombosis
THANK YOU FOR YOUR ATTENTION
Raul A. DeLa Cadena, M.D.
Temple University School of Medicine
Philadelphia, Pennsylvania
“La Mujer” David Alfaro Siqueiros 1964-1971
