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Targeted versus untargeted omics - the CAFSA story.
- Source :
-
Journal of inherited metabolic disease [J Inherit Metab Dis] 2018 May; Vol. 41 (3), pp. 447-456. Date of Electronic Publication: 2018 Feb 08. - Publication Year :
- 2018
-
Abstract
- Background: In 2009, untargeted metabolomics led to the delineation of a new clinico-biological entity called cerebellar ataxia with elevated cerebrospinal free sialic acid, or CAFSA. In order to elucidate CAFSA, we applied sequentially targeted and untargeted omic approaches.<br />Methods and Results: First, we studied five of the six CAFSA patients initially described. Besides increased CSF free sialic acid concentrations, three patients presented with markedly decreased 5-methyltetrahydrofolate (5-MTHF) CSF concentrations. Exome sequencing identified a homozygous POLG mutation in two affected sisters, but failed to identify a causative gene in the three sporadic patients with high sialic acid but low 5-MTHF. Using targeted mass spectrometry, we confirmed that free sialic acid was increased in the CSF of a third known POLG-mutated patient. We then pursued pathophysiological analyses of CAFSA using mass spectrometry-based metabolomics on CSF from two sporadic CAFSA patients as well as 95 patients with an unexplained encephalopathy and 39 controls. This led to the identification of a common metabotype between the two initial CAFSA patients and three additional patients, including one patient with Kearns-Sayre syndrome. Metabolites of the CSF metabotype were positioned in a reconstruction of the human metabolic network, which highlighted the proximity of the metabotype with acetyl-CoA and carnitine, two key metabolites regulating mitochondrial energy homeostasis.<br />Conclusion: Our genetic and metabolomics analyses suggest that CAFSA is a heterogeneous entity related to mitochondrial DNA alterations either through POLG mutations or a mechanism similar to what is observed in Kearns-Sayre syndrome.
- Subjects :
- Adult
Case-Control Studies
Cerebellar Ataxia cerebrospinal fluid
Cerebellar Ataxia genetics
Cerebellar Ataxia metabolism
DNA Mutational Analysis
DNA Polymerase gamma genetics
DNA, Mitochondrial analysis
Female
Humans
Male
Mass Spectrometry
Siblings
Tetrahydrofolates analysis
Exome Sequencing methods
Cerebellar Ataxia diagnosis
Genomics methods
Metabolomics methods
N-Acetylneuraminic Acid cerebrospinal fluid
Tetrahydrofolates cerebrospinal fluid
Subjects
Details
- Language :
- English
- ISSN :
- 1573-2665
- Volume :
- 41
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Journal of inherited metabolic disease
- Publication Type :
- Academic Journal
- Accession number :
- 29423831
- Full Text :
- https://doi.org/10.1007/s10545-017-0134-3