Next Generation Metabolic Screening is a novel technique that can be applied to body fluids as urine, plasma or cerebrospinal fluid for the diagnosis of inborn errors of metabolism. The technique gives a holistic view on metabolism (metabolomics) and uses LC_Qtof mass spectrometry. The technique was developed in Nijmegen, The Netherlands in the group of Prof Ron Wevers (ron.wevers@radboudumc.nl)
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2014 lecture next generation metabolic screening - Marrakech
1. Next Generation Metabolic Screening
11th Middle East Metabolic
Group meeting - MEMG
22-25 October 2014,
Marrakech, Morocco
Prof. dr. Ron Wevers,
Department of Laboratory Medicine,
Radboudumc, Nijmegen, The Netherlands
2. 1997
There is no single analytical platform that can
measure all metabolites
The metabolome
3. NMR based metabolomics
BODY FLUID NMR SPECTROSCOPY IN INBORN ERRORS OF METABOLISM
Body fluid NMR
• Diagnosis of 106 IEM (1D
and 2D COSY)
• 1H resonances from 158
metabolites involved IEM
• Seven novel inborn errors
could be defined
Limitation
Sensitivity: low micromolar
range
4. Molecular complexity in Life Science
Number of Dynamic
molecular entities range__
Genomics 104 103
Proteomics 106 1010+
Metabolomics 104 106+
Typical eukaryotic organisms contain between 4000 and 50000
metabolites (Kegg: 16896; HMDB 2012: 7900; HMDB 3.6: 41808)
6. Metabolomics – analysis of “all” metabolites
Human plasma, CSF
(urine)
Controls vs. patient
Agilent QTOF MS-data
- Reverse phase liquid chromatography
- Positive and negative mode
- Features
• Accurate mass (165.07898)
• Retention time
• Intensity
(New) biomarkers for diseases
XCMS
Alignment
Peak comparison
> 10,000 Features
8. Accuracy of Q-tof analysis
Deviation from actual mass for 19 metabolites
(Mass range 90.0552 – 428.3737 Dalton)
mass number of
metabolites
0.0000 2
0.0001 10
0.0002 4
0.0003 2
0.0004 1
19
9. Q-tof sensitivity
Sensitivity
Q-TOF
low nanomolar range
NMR
low micromolar range
Factor 1000 more
sensitive than
NMR!
Pipecolic acid
S/N=20
500 nmol/L
50 nmol/L
5 nmol/L
no addition
Pipecolic acid added to urine (diluted 50x)
10. Validation Next Generation Metabolic Screening (NGMS)
• Comparison signal intensity with
concentratios classical assays
• Mass accuracy on QTOF:
95%: ΔM < 0,0003 Da
(range: 90-425 Da; n=19)
• Sensitivity of UHPLC-QTOF MS assay in low nM range!
(~1000 fold more sensitive than NMR)
• Intra: CV in RT: <0.5%; CV in signal intensity: <15%
Inter: CV in RT: <1%; CV in signal intensity: <25-30%
• Clinical validation: diagnosis established in
16 individual patients with different IEMs
Standard operation procedure for plasma and CSF samples introduced in patient care in 2014
11. Where is/are the biomarker(s)?
10,480
features
10,480 Features (incl. adducts etc)
Mass, Retention time, Intensity
12. INPUT
Endogenous metabolites
Diet derived
Intestinal flora input
Medication
ANALYTICAL
Original small molecules
Adduct information (Na+, K+, NH4
+)
In source fragments
13C variants
How to explain 10.000 features in plasma?
13. Which features are the IEM biomarkers
10,480 features
Experiment
Alignment
Peak Comparison
Raw data
Corrected t-test
Intensity/P Ranking
Dataanalyses
Identification T20
Verification
DataPreprocessing
&Pretreatment
Data
interpretation
19. Targeted analysis of markers specific for xanthinuria type II
CONCLUSION:
Xanthinuria type II (diagnosed in urine sample without allopurinol loading)
Hydantoin 5-propionate Pyridoxal
20. The clinical validation
Amino acid
disorders
Fatty acid
oxidation
Organic acidurias Miscellaneous
PKU MCAD MSUD Xanthinuria II
Hyperprolinemia II VLCAD HMG-CoA lyase Amino acylase I
Hyperlysinemia MCC Antiquitin (ATQ) def.
MAT I/III IVA Beta-ketothiolase
Alcaptonuria Dimethylglycinuria
Ureidopropionase
Diagnosis on plasma samples
Current status: 23 inborn errors
23. Nijmegen four day march
The bridge between the exome and the metabolome
The Nijmegen approach
24. Conclusions
• Next Generation Metabolic Screening (NGMS) introduced
in diagnostics of the individual patient
• NGMS will change the metabolic laboratory
• NGMS bridges whole exome sequencing and metabolic
diagnostics: integrative biology in a functional genomics
setting
• The technique we have developed is also of interest outside
the field of inborn errors
25. METABOLIC SCREENING
The individual patient suspected for an IEM
WES and NMGS in parallel together with dept. Genetics Radboudumc
26. C.D.G Huigen
E. van der Heeft
U.F.H. Engelke
R.A. Wevers
L.A.J. Kluijtmans
Nijmegen metabolomics
C. van Karnebeek,
Vancouver
J. Engel
S. Wortmann-Hagemann
30. Challenge - 3
The big data
• Pathway analysis
• How to integrate Whole Exome Sequencing data with the
metabolomics data?
METABOLIC SCREENING
IN THE INDIVIDUAL PATIENT
DNA SEQUENCING
IN THE INDIVIDUAL PATIENT
Integrating
software
The next step
The coding data of the human
genes
10,480