Metabolomics; Metabolic profiling; In vitro models; ALDH7A1 ; Antiquitin; Pyridoxal 5'-phosphate; pyridoxine-dependent epilepsy (PDE); Vitamin B6; Mass spectrometry; Biofluids
Crowther Lisa M., Mathis Déborah, Poms Martin, Plecko Barbara (2019), New insights into human lysine degradation pathways with relevance to pyridoxine dependent epilepsy due to antiquitin deficiency, in Journal of Inherited Metabolic Disease
Wilson Matthew P., Plecko Barbara, Mills Philippa B., Clayton Peter T. (2019), Disorders Affecting Vitamin B 6 metabolism, in Journal of Inherited Metabolic Disease
de Rooy R.L.P., Halbertsma F.J., Struijs E.A., van Spronsen F.J., Lunsing R.J., Schippers H.M., van Hasselt P.M., Plecko B., Wohlrab G., Whalen S., Benoist J.F., Valence S., Mills P.B., Bok L.A. (2018), Pyridoxine dependent epilepsy: Is late onset a predictor for favorable outcome?, in European Journal of Paediatric Neurology
, 22(4), 662-666.
Crowther L. M., Poms M., Plecko Barbara (2018), Multiomics tools for the diagnosis and treatment of rare neurological disease, in Journal of Inherited Metabolic Disease
, 41(3), 425-434.
Srinivasaraghavan Rangan, Parameswaran Narayanan, Mathis Deborah, Bürer Celine, Plecko Barbara (2018), Antiquitin Deficiency with Adolescent Onset Epilepsy: Molecular Diagnosis in a Mother of Affected Offsprings, in Neuropediatrics
, 49(02), 154-157.
The overall objective of this research project is to use metabolomics to identify pathomechanisms leading to variations in the outcome of patients with pyridoxine-dependent epilepsy due to ALDH7A1 deficiency. ALDH7A1 deficiency is a paradigm of how our limited understanding of underlying pathomechanisms leaves many patients with suboptimal clinical outcome. Pyridoxine-dependent epilepsy (PDE) has been known since 1954 but only within the last decade its molecular background has been elucidated. The majority of PDE cases is caused by a block in lysine degradation due to ALDH7A1 deficiency with the accumulation of metabolic intermediates that inactivate the essential cofactor vitamin B6 (pyridoxine; pyridoxal 5’-phosphate (PLP)). It has become obvious, that irrespective of early treatment, about 75% of ALDH7A1 deficient patients suffer from intellectual disability (IQ < 70). This statistic suggests permanent neuronal damage is caused by the accumulation of metabolic intermediates associated with impaired activity of ALDH7A1. Interestingly no firm correlation has been found between genotype, accumulation of known metabolites and intellectual outcome. We hypothesize that the variation in cognitive outcome of ALDH7A1 deficiency could be caused by crucial pathomechanisms outside of the lysine catabolic pathway, which have not been identified to date.Here we propose the use of mass spectrometry-based metabolomics to investigate the comprehensive biochemical perturbations due to ALDH7A1 deficiency.Aim 1 Generation of in vitro models of ALDH7A1 deficiency enable the comparative metabolomics of ALDH7A1 deficiency under precisely controlled experimental conditions. We will develop tissue culture models in patient derived fibroblasts, in addition to using CRISPR/Cas genome editing to generate ALDH7A1 deficient astrocyte-neuronal co-cultures.Aim 2 High-resolution mass spectrometric metabolomic analysis of in vitro models and patient biofluids will be performed by a targeted metabolomic analysis of known pathways affected in ALDH7A1 deficiency; isotopic tracers in model systems will reveal the fate of essential metabolites e.g. PLP and its products. Untargeted metabolomic analysis will reveal hitherto unrecognized pathomechanisms that may be crucial to our understanding of the variability in outcome. Metabolic profiles from the in vitro models will be compared to those of biofluids in ALDH7A1 deficient patients with normal cognitive outcome versus those with cognitive deficits as well as healthy controls.A better understanding of all crucial pathomechanisms in ALDH7A1 deficiency has the potential to improve therapeutic options and ultimately improve the long-term outcome of affected children.