Transcript Potkin et al, 2002 - National Alliance for Medical Image Computing

NA-MIC
National Alliance for Medical Image Computing
http://na-mic.org
Core 3.2 Activities (Toronto)
University of Toronto—Neurogenetics Section, Center
for Addiction and Mental Health
James Kennedy MD Head Neurogenetics Section CAMH
Aristotle Voineskos MD Chief Resident in Psychiatry CAMH
Natalia Potapova MSc Neurogenetics Database Coordinator
Claudia Rothe MD Research Fellow Neurogenetics CAMH
Fabio Macciardi MD PhD Statistical Genetics Consultant
Natalie Bulgin MSc Lab Coordinator Neurogenetics
Datasets Available
• (1) Toronto genetic data on 300
schizophrenic patient and matched controls;
• (2) Vancouver, 47 first episode schizophrenia
patients with structural MRI scans, cognitive
testing, and genetic; and
• (3) Irvine 25 schizophrenic patients with fMRI,
PET, EEG and 100k SNP genetic data.
• How do we integrate the parts of Core 3.2?
National Alliance for Medical Image Computing
http://na-mic.org
Genetics of Schizophrenia: Neuroimaging
Measures
James L. Kennedy MD FRCPC
Head, Neurogenetics Section,
Director, Neuroscience Research Dept
Centre for Addiction and Mental Health;
I’Anson Professor of Psychiatry and Medical
Science,
University of Toronto
Genetics Basics I
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Cell => nucleus => chromosome => gene
Genome = all the chromosomes/genes
Gene structure: coding, promoter, UTR
Gene variant = allele
Pair of alleles = genotype
Mutation = rare variant <1% that disrupts gene
function
• Combination of variants = haplotype
Success of Molecular Genetics
Single Gene Diseases (Mendelian)
Complex Diseases
• More than 600 disease genes
discovered & screening now
routine for many of these
• Early onset Alzheimers presenilin genes pointing to new
medications
• Early onset breast cancer:
diagnostic genetic tests
• Cystic fibrosis: holdup in
delivery of healthy gene
• Huntingtons: toxic triplet repeat
• Common Alzheimers: APOE gene
predicts part of the risk
• AIDS: the CCR5 gene predicts
progression of disease
• Insulin dependent diabetes: HLA
gene site is pointing to
autoimmune mechanism
• Coronary artery disease: multiple
risk genes indicated
• ADHD: dopamine D4 and
transporter genes associated
Molecular Genetic Approach
Gene
Gene Expression
Pharmacogenetics
Variants
Pharmacology
Neurobiology
Phenotype
Psychophysiology
Endophenotype
Sub-pheno
Neuroimaging
Will DNA Microarrays provide
the important answers?
Microarrays: 1,000,000 genetic
tests in two hours
John Nash:
30 Years of Schizophrenia
Cytoarchitectural abnormalities
Control
Schizophrenia
Comparison of
hippocampal pyramids at
the CA1 and CA2 interface
between control and
schizophrenic.
Cresyl violet stain,
original magnification X250
Conrad et al. (1991)
Arch Gen Psychiatry
BDNF Gene Structure
Val-66-met
(GT)n repeat
(promoter function?)
Transmission Disequilibrium Test
for BDNF val66/met in Schizophrenia
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Non Transmissions
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* TDT for val66
c2 = 4.31; 1 df; p = 0.03
Muglia et al, (2002)
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+ S-TDT was used for the Canadian sample to
incorporate the available affected sibs
Haplotype TDT: BDNF (GT)n repeat &
val66met in schizophrenia
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* HTDT for 170-val66
c2 = 7.11; 1 df;
p = 0.007
Muglia et al, (2002)
BDNF val66met: MRI functional
brain imaging (Egan et al, Cell 2003)
The red/yellow areas
indicate brain regions
(primarily hippocampus)
that function differently
between val/val (n=8) and
val/met (n=5) subjects
while performing a working
memory task. Subjects with
the met allele had more
abnormal function.
Pezawas et al,
2005.
Grey matter
volume reduced
in BDNF met
carriers in
hippocampus, R
DLPC, and L
frontal convexity.
BDNF and Hippocampal Volume
(Szeszko et al, 2005)
-- People with val/val
homozygotes had
higher hippocampal
volume than val/met
(f=8.72, df=39, p=0.005;
sex and total brain volume
as covariates).
-- effect was larger in
schiz patients than
controls (partial eta sq
= 0.44 vs 0.10)
NMDA as a final common path for Schizophrenia?
BDNF (11p)
Neuregulin (8p)
Muglia et al, 2003
Syntaxin (7q)
Stefansson et
al, 2002.
-Icelandic
-Scottish
-German
ErbB4
Wong & Kennedy, in prep.
Glu
Dystrobrevin (6p)
Ca++
Straub et al, 2002
Irish families
Chumakov
et al, 2002
G72
Canadian &
Russian families
-also now +ve in
Bipolar familes
(13q)
+
D-amino acid
oxidase (12p)
Current
Medications
Gly
Dopamine
D2
D1
calcineurin
Tonegawa
group,
PNAS July
8/03
DRD1, PET FDG, & Clozapine Response
Genotype 2/2
BPRS = 30%
Improvement
Genotype 1/2
BPRS = 7%
Genotype
Worsening1/2
(Potkin et al, 2002)
Brain Metabolism Following Haloperidol
Treatment by D3 Genotype (FDG n=14)
Gly-Ser
& Ser-Ser
(n=9)
Haloperidol (5wks) Baseline
Baseline
Gly-Gly
(n=5)
(UCI Brain Imaging Centre; Potkin, Basile & Kennedy, 2002)
Common Serotonin Transporter
Polymorphisms (17q11.1-q12)
44 bp repeat
(5-HTTLPR)
5’
17 bp repeat (VNTR)
Exon 1B
Exon 2
3’
Promoter region
Short (deleted)= C14
Long (inserted) = C16
Cells homozygous for the l allele have higher
concentrations of 5-HTT mRNA and express
two-fold 5-HTT reuptake sites than s/s or s/l
cells (Lesch et al, 1996);
Similar differences found in 5-HTT binding
levels in human brain (Little et al, 1998; Lesch
et al, 1998).
Serotonin Transporter Genetic Variation and the
Response of the Human Amygdala
Individuals carrying
the s variant of the
5HTTLPR exhibit an
increased amygdala
response to fearful
stimuli when
compared to those
carrying the l
variant.
A.R. Hariri, V.S. Mattay, A. Tessitore, B. Kolachana, F. Fera, D.
Goldman, M.F. Egan, D.R. Weinberger. Science, 297: 400-403 (2002).
SNAP25 Gene vs Grey Matter
• Synaptic transmission activity partly
determines extent of grey matter
• SNAP25 is a major component of synaptic
vesicle release of neurotransmitters
• SNAP25 associated with schizophrenia
(Potkin sample) and with treatment
response (Muller et al, in press)
• Role in grey matter volume?
EXTRACTING DATA FOR ANALYSIS
Data are returned in a format suitable for association-type studies (m-link or casecontrol). Additional formats may be designed as needed (such as vertical
haplotypes { 12 21 21 11 12 22 21 21 } ). Data may be transcribed and converted to document
formats supported by the analysis program (tab de-limited text, etc…).
With access to source codes, or by invoking special features in
downstream applications, the database can include automated running of
analyses or transfer of data to other spreadsheets/databases.
Genetics and Grey Matter
Will the Brain Derived Neurotrophic Factor
(BDNF) Gene Predict Grey Matter Volume?
BDNF-1 SNP
BDNF-2
Exon 11
Val-66-met
(GT)n repeat
(function? mRNA
stability)
BDNF-3
BDNF-4
BDNF val66met: MRI functional
brain imaging (Egan et al, Cell 2003)
The red/yellow areas
indicate brain regions
(primarily hippocampus)
that function differently
between val/val (n=8) and
val/met (n=5) subjects
while performing a working
memory task. Subjects with
the met allele had more
abnormal function.
Haplotype TDT: BDNF (GT)n repeat &
val66met in schizophrenia
*
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30
25
20
Transmissions
Non Trans
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10
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Ha
Ha
Ha
Ha
* HTDT for 170-val66
c2 = 7.11; 1 df;
p = 0.007
Muglia et al, (2002)
SNAP25 Genotype in
Schizophrenia vs Controls
Not for distribution
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Chi-sq = 9.4;
df=2; p=0.009
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Potkin
sample
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Contr
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Genetics and White Matter
Myelin Oligodendrocyte
Glycoprotein (MOG)
 may function as:
 a cellular adhesion molecule
 a regulator of oligodendrocyte microtubule stability
 a mediator of interactions between myelin and the immune
system, particularly as an activator of the classical complement
cascade via activation of C1q (Johns and Bernard, 1997).
Location of MOG Gene in 6p21.3 Region
(MHC Region)
DP
DN
DM
LMP/TAP
DO
DQ
DR
C4A,
C4B, C2,
factor B,
21-OHase
Class II
NOTCH4
TNF
HLA-B
Class III
HLA-C
HLA-A
HLA-G
HLA-F
MOG
Class I
 
telomere
centromere
(CA)n
(TAAA)n
~ 2.6 Mb
Figure 2. Human MHC region and genes within the region.
Prefrontal fMRI activity & myelin reduced in schizophrenia:
Core 3.1
Figure 3:1-4: Statistical parametric maps of the fractional anisotropy
(FA) (left) and Magnetic Transfer Ratio (MTR) (myelin) (right) group
comparison. Similar areas in yellow on both maps correspond to the
location of both the internal capsule and prefrontal white matter,
and indicate smaller values of FA and myelin in schizophrenia
patients (n=14) compared with controls (n=15).
Will MOG gene variants predict
white matter abnormalities?
(CA) repeat
Promoter
region
C1334T
Start
codon
C10991T
(TAAA) repeat
Coding region
(diagram not to scale)
MOG vs Total Brain White Matter
• Sample: Dr. Honer UBC – 47 schiz, 24 cont
• Phenotype: automated output from standard structural MRI
– total grey and white matter
• MRI=> 3D SPGR:
FOV 26cm
TE 11.2ms TR 2.1ms
Matrix 256 x 256
Thickness 1.5 mm
Angle - perpendicular to AC-PC line
Acquisition time - 6 minutes
Not for distribution
• C1334T marker genotype associated with white matter
volume (P=0.003)
• Other MOG markers negative
• All MOG markers negative for total grey matter volume
MAG (Myelin Associated
Glycoprotein)
• Reduced expression of MAG in postmortem
studies of schizophrenic brain (frontal, cingulate,
hippocampus)
• Found in periaxonal membrane of oligodendrocyte
and may be responsible for maintaining contact
between myelin forming cells and the axon
• Is a transmembrane adhesion molecule (CAM)
present in both CNS and PNS myelin
• Wan et al (Neuroscience Letters, 2005)
Myelin Associated Glycoprotein Gene (MAG)
Yang, 2005
MAG SNPs
• Two single nucoleotide polymorphisms examined
located in intron 8
• Rs720309 (T/A)
• Rs720308 (G/A)
• Both SNPs significant in Chinese schizophrenia
sample, and haplotype significant as well
• Both SNPs associated with total white matter
volume in schizophrenia cases, but not in controls
MAG rs720309 (T/A) associated with
White Matter Volume in Psychosis Cases
Estimated Marginal Means of
mm3
Patients' White Matter Volume
540000
P = 0.016
530000
520000
510000
500000
T/T (N=34)
T/A (N=11)
Patients' MAG(rs720309) Genotype
MAG rs720308 (G/A) associated with
White Matter Volume in Psychosis Cases
Estimated Marginal Means of
mm3
Patients' White Matter Volume
540000
P = 0.002
530000
520000
510000
500000
A/G (N=12)
G/G (N=33)
Patients' MAG(rs720308) Genotype
Rs 720308 and rs 720309 not associated with
total white matter volume in controls
Estimated Marginal Means of Whitemat
Estimated Marginal Means of whitemat
552000.00
552000.00
551000.00
Estimated Marginal Means
Estimated Marginal Means
551000.00
550000.00
549000.00
550000.00
549000.00
548000.00
547000.00
546000.00
548000.00
12
22
genotype
(1,2 = GA), (2,2 = AA)
11
12
Genotype
(1,1 = TT), (1,2 = TA)
CNP SNP not associated with total white
matter in early psychosis cases
• 2’,3’-cyclic nucleotide 3’-phosphodiesterase
• Reduced expression reported in schiz brain
• Knockout mice display schiz-like CNS path
(reduced brain size, ventricle enlargement, corpus
callosum atrophy)
• Primary fxn may be in microtubule assembly, and
cytoskeletal protein interaction
• Region of interest assoc may be more fruitful
(e.g. corpus callosum)
How can we move things forward
collaboratively?
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Region of interest data (grey matter)
Region of interest data (white matter)
fMRI
DTI
Find ways to understand how genetic
variation contributes to differences in these
imaging measures
Imaging Measures to Combine
Genetic Data with
• Region of interest data
– Grey matter (e.g. BDNF hippocampal volume)
– White matter (e.g. CNP corpus callosum volume)
– fMRI measures (e.g. COMT gene with working
memory as per fMRI)
All in normals and in cases
Imaging Measures to Combine
Genetic Data with
DTI
• Fractional Anisotropy (a measure of the fraction of
the magnitude of the tensor that can be ascribed to
anisotropic diffusion)
• e.g. MAG or MOG with FA in normals and in
cases; can look at FA of cingulate bundle as it is
known MAG is downregulated in cingulate cortex
of schizophrenia cases
How can we adapt the current
toolkit to integrate genetics ?
• Incorporate our database
• Make easy links/button clicks in Slicer such
that genetic data can be added for each
subject
• Integrate statistical programs or links within
slicer such that a simple ANOVA/ANCOVA
can be carried out
Genetics Summary
• SNAP25 gene associated with schizophrenia in
Potkin sample, and Toronto sample
• BDNF gene candidate for grey matter vol and fxn
• Serotonin transporter gene for amygdala function
• DISC1 gene for cortical thickness
• Dopamine genes predict cortical & striatal fxn?
• Newest data: MOG and MAG genes associated
with total brain white matter (MOG hypothesized
in grant app)
• Relational database developed for organizing
genetic + clinical + imaging data
• Training available in genetics
National Alliance for Medical Imaging and Computing