Rare & Orphan Lab · DeCure for X

DeCure for D-2-hydroxyglutaric aciduria

DeCure's autonomous Rare AI scientist is researching a drug-repurposing hypothesis for D-2-hydroxyglutaric aciduria — screening already-approved drugs against its 1-gene Open Targets disease module to publish open-access research. Research is fast; the path to publication is funded in milestone stages.

Disease module1 genesLead labRare & Orphan
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Rare & OrphanDOID:0050575$DeCureRare

The disease map

Disease moduleD-2-hydroxyglutaric aciduria maps to a 1-gene Open Targets module — the target space DeCure's AI scientist screens approved drugs against.
DeCure.ai methodSignature reversal (LINCS) plus network proximity (STRING) rank already-approved drugs likely to perturb this module — the same engine that produces DeCure.ai's repurposing hypotheses.
Repurposing thesisScreening approved medicines against this disease module, then publishing the evidence for the strongest candidate. Known pharmacology and human exposure data make the first question sharper — they do not establish safety or efficacy in a new indication.

Research record

01
ResearchComing soon
Candidate research + dossier — target rationale, drug-repurposing thesis and evidence pack.proof: Published dossier + on-chain hash
02
ValidationComing soon
In-vitro biological validation at a contract research org (CRO).proof: CRO contract + in-vitro report
03
Peer review & paperComing soon
Peer-reviewed paper published open-access (preprint + journal).proof: DOI + open-access link + on-chain hash

Current lead

No approved-drug candidate for d-2-hydroxyglutaric aciduria is corroborated in the literature DeepSearch retrieved. Some conditions are managed with non-pharmacological care — a device, surgery or physical therapy — rather than a medicine; that may be the case here, or the literature we found may simply be too sparse yet to support a drug-repurposing angle.

Molecular view

isocitrate dehydrogenase (NADP(+)) 2 (IDH2)IDH2 is one of the genes genetically linked to this disease in Open Targets — shown as context, not as a drug target we're pursuing: no approved-drug candidate for this disease is yet corroborated in the literature we found.

Loading structure…
helix sheet ndpdrag to rotate · scroll to zoom

RCSB Protein Data Bank · entry 5I96 · 1.55 Å · ligand NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (NDP). Experimental structure, not a prediction.

What the evidence adds up to

In 50 patients with D-2-hydroxyglutaric aciduria, presumed pathogenic mutations were found in only 24 in the D2HGDH gene, and those mutation-positive patients had significantly lower D-2-HG concentrations in body fluids than mutation-negative patients. Enzyme assay confirmed that all patients with mutations had impaired D-2-hydroxyglutarate dehydrogenase activity, while patients with normal enzyme activity had no mutations. This implies multiple genetic loci cause hyperexcretion of D-2-HG, leading to a proposed classification: Type I with D2HGDH deficiency, and idiopathic D-2-HGA with normal enzyme activity and higher D-2-HG levels.

A functional enzyme assay using stable-isotope-labelled D-2-hydroxy[3,3,4,4-2H4]glutarate was developed to measure D-2-hydroxyglutarate dehydrogenase activity. Mean control activities were 298 ± 207 pmol/h per mg protein in fibroblasts and 1670 ± 940 in lymphoblasts. Patient cell lines with pathogenic D2HGDH mutations showed considerably decreased activities, for example below 41 pmol/h per mg protein. In a separate functional study of 31 missense variants introduced into HEK293 cells, 18 variants caused almost complete ablation of enzyme activity, while 13 showed residual activities between 17% and 94% of control.

A case report describes a 37-year-old bedridden male patient with 2-hydroxyglutaric aciduria diagnosed three decades after onset. Combination treatment with riboflavin and levocarnitine improved his condition, allowing him to walk by himself. Another report notes that only 295 events of L-2-hydroxyglutaric aciduria have been described in the literature up to 2022, and presents two sibling sisters aged 12 and 13 from a consanguineous family.

What is still missing: no controlled trial of riboflavin and levocarnitine exists; the genetic heterogeneity means many patients lack a molecular diagnosis; no treatment has been tested in a prospective cohort; patient stratification by genotype and residual enzyme activity is not yet used to guide therapy; funding for natural history studies and drug development for this ultra-rare disorder remains minimal.

Evidence

Retrieved by DeepSearch across 234,678,978 indexed works and resolved on OpenAlex — ranked by citations, including the results that did not work.

Journal of Inherited Metabolic Disease · 2012 · 293 citations · open access

Progress in understanding 2‐hydroxyglutaric acidurias

AbstractThe organic acidurias D: -2-hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and combined D,L-2-hydroxyglutaric aciduria (D,L-2-HGA) cause neurological impairment at young age. Accumulation of D-2-hydroxyglutarate (D-2-HG) and/or L-2-hydroxyglutarate (L-2-HG) in body fluids are the biochemical hallmarks of these disorders. The current review describes the knowledge gathered on 2-hydroxyglutaric acidurias (2-HGA), since the description of the first patients in 1980. We report on the clinical, genetic, enzymatic and metabolic characterization of D-2-HGA type I, D-2-HGA type II, L-2-HGA and D,L-2-HGA, whereas for D-2-HGA type I and type II novel clinical information is presented which was derived from questionnaires.

https://doi.org/10.1007/s10545-012-9462-5
Clinical Chemistry · 2004 · 150 citations · open access

Measurement of Urinary d- and l-2-Hydroxyglutarate Enantiomers by Stable-Isotope-Dilution Liquid Chromatography–Tandem Mass Spectrometry after Derivatization with Diacetyl-l-Tartaric Anhydride

AbstractBACKGROUND: The differential diagnosis of D-2-hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and the combined D/L-2-hydroxyglutaric aciduria (D/L-2-HGA) can be accomplished only by the measurement of the corresponding 2-hydroxyglutarate (2-HG). Available methods for the determination of D- and L-2-HG in urine are either time-consuming and expensive or have not been extensively validated. We aimed to develop a method for their rapid and sensitive measurement. METHODS: We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of D- and L-2-HG with stable-isotope-labeled internal standards. Urine samples of 20 microL were mixed with 250 microL of methanol containing the internal standards and subsequently dried under nitrogen. The analytes were derivatized by use of diacetyl-L-tartaric anhydride (DATAN) to obtain diastereomers, which were separated on an achiral C18 HPLC column and detected by MS/MS in multiple-reaction-monitoring mode. RESULTS: The use of DATAN as chiral derivatization reagent provided very well separated peaks of the formed diastereomers of D- and L-2-HG, with a total runtime of 5 min. The inter- and intraassay CVs for D- and L-2-HG ranged from 3.4% to 6.2%. Mean recoveries of D- and L-2-HG, evaluated on two concentrations, were 94%. Detection limit of the presented method was 20 pmol for a sample volume of 20 microL. Method comparison of the LC-MS/MS method with a gas chromatography-mass spectrometry method, in which D- and L-2-HG were derivatized with R-(-)-butanol, showed good agreement between the two methods. CONCLUSIONS: Urinary D- and L-2-HG can be analyzed by MS/MS after derivatization with DATAN. The presented method may be suitable for the differential diagnosis of 2-HGA.

https://doi.org/10.1373/clinchem.2004.033399
Human Mutation · 2009 · 74 citations

Evidence for genetic heterogeneity in D-2-hydroxyglutaric aciduria

AbstractWe performed molecular, enzyme, and metabolic studies in 50 patients with D-2-hydroxyglutaric aciduria (D-2-HGA) who accumulated D-2-hydroxyglutarate (D-2-HG) in physiological fluids. Presumed pathogenic mutations were detected in 24 of 50 patients in the D-2-hydroxyglutarate dehydrogenase (D2HGDH) gene, which encodes D-2-hydroxyglutarate dehydrogenase (D-2-HGDH). Enzyme assay of D-2-HGDH confirmed that all patients with mutations had impaired enzyme activity, whereas patients with D-2-HGA whose enzyme activity was normal did not have mutations. Significantly lower D-2-HG concentrations in body fluids were observed in mutation-positive D-2-HGA patients than in mutation-negative patients. These results imply that multiple genetic loci may be associated with hyperexcretion of D-2-HG. Accordingly, we suggest a new classification: D-2-HGA Type I associates with D-2-HGDH deficiency, whereas idiopathic D-2-HGA manifests with normal D-2-HGDH activity and higher D-2-HG levels in body fluids compared with Type I patients. It remains possible that several classifications for idiopathic D-2-HGA patients with diverse genetic loci will be revealed in future studies.

https://doi.org/10.1002/humu.21186
Journal of Inherited Metabolic Disease · 2009 · 17 citations

Measurement of <scp>d</scp>‐2‐hydroxyglutarate dehydrogenase activity in cell homogenates derived from <scp>d</scp>‐2‐hydroxyglutaric aciduria patients

AbstractD: -2-Hydroxyglutaric aciduria (D: -2-HGA) is a neurometabolic disorder characterized by elevated levels of D: -2-hydroxyglutarate (D: -2-HG) in physiological fluids. Recent findings revealed that mutations in the D2HGDH gene, encoding D: -2-hydroxyglutarate dehydrogenase, cause D: -2-HGA. So far, a functionalenzyme assay to determine D: -2-hydroxyglutarate dehydrogenase activity, converting D: -2-HG into 2-ketoglutarate (2-KG), has been unavailable. We have now developed a unique enzyme assay for the determination of D: -2-hydroxyglutarate dehydrogenase activity in cells derived from D: -2-HGA patients and controls. The enzyme assay was performed using enantiomerically pure stable-isotope-labelled D: -2-hydroxy[3,3,4,4-(2)H(4)]glutarate. This substrate is convertedby D: -2-hydroxyglutarate dehydrogenase into 2-[3,3,4,4-(2)H(4)]ketoglutarate, which is subsequently converted into L: -[3,3,4,4-(2)H(4)]glutamate by L: -glutamate dehydrogenase, present in saturating amounts in cell homogenates. Enzyme activities were quantified using LC-MS/MS. The mean activities in control fibroblast and lymphoblast homogenates were 298 +/- 207 and 1670 +/- 940 pmol/h per mg protein, respectively. In fibroblast and lymphoblast cell lines derived from patients with pathogenic mutations in the D2HGDH gene, considerably decreased enzyme activities (e.g. <41 pmol/h per mg protein) were found compared with controls. This enzyme assay will have additional utility in further differentiating patients with D: -2-HGA and L: -2-HGA and in assessing the residual activities linked to pathogenic mutations in the D2HGDH gene.

https://doi.org/10.1007/s10545-009-1104-1
Human Mutation · 2019 · 9 citations · open access

D‐2‐hydroxyglutaric aciduria Type I: Functional analysis of <i>D2HGDH</i> missense variants

AbstractD-2-hydroxyglutaric aciduria Type I (D-2-HGA Type I), a neurometabolic disorder with a broad clinical spectrum, is caused by recessive variants in the D2HGDH gene encoding D-2-hydroxyglutarate dehydrogenase (D-2-HGDH). We and others detected 42 potentially pathogenic variants in D2HGDH of which 31 were missense. We developed functional studies to investigate the effect of missense variants on D-2-HGDH catalytic activity. Site-directed mutagenesis was used to introduce 31 missense variants in the pCMV5-D2HGDH expression vector. The wild type and missense variants were overexpressed in HEK293 cells. D-2-HGDH enzyme activity was evaluated based on the conversion of [2H4]D-2-HG to [2H4]2-ketoglutarate, which was subsequently converted into [2H4]L-glutamate and the latter quantified by LC-MS/MS. Eighteen variants resulted in almost complete ablation of D-2-HGDH activity and thus, should be considered pathogenic. The remaining 13 variants manifested residual activities ranging between 17% and 94% of control enzymatic activity. Our functional assay evaluating the effect of novel D2HGDH variants will be beneficial for the classification of missense variants and determination of pathogenicity.

https://doi.org/10.1002/humu.23751
Annals of Indian Academy of Neurology · 2014 · 9 citations · open access

An interesting case of metabolic dystonia: L-2 hydroxyglutaric aciduria

AbstractL-2-hydroxyglutaric aciduria (L-2-HGA), a neurometabolic disorder caused by mutations in the L-2 hydroxyglutarate dehydrogenase (L-2-HGDH) gene, presents with psychomotor retardation, cerebellar ataxia, extrapyramidal symptoms, macrocephaly and seizures. Characteristic magnetic resonance imaging findings include subcortical cerebral white matter abnormalities with T2 hyperintensities of the dentate nucleus, globus pallidus, putamen and caudate nucleus. The diagnosis can be confirmed by elevated urinary L-2 hydroxyglutaric acid and mutational analysis of the L-2-HGDH gene. We report two siblings with dystonia diagnosed by classical neuroimaging findings with elevated urinary 2 hydroxyglutaric acid. Riboflavin therapy has shown promising results in a subset of cases, thus highlighting the importance of making the diagnosis in these patients.

https://doi.org/10.4103/0972-2327.128565
American Journal of Medical Case Reports · 2022 · 0 citations · open access

Case Report: L-2-Hydroxyglutaric Aciduria in Sibling Sisters

AbstractOur case report presents one of the rarely seen disorders L-2-hydroxyglutaric aciduria. Very little information is given in the literature and it remained undiagnosed until the 1980s. According to our information, only 295 events have been described in the literature till date. Our case report describes the disease manifestations, clinical pictures, and a review of the relevant literature on L-2-hydroxyglutaric aciduria. Our patients were females aged 12 and 13 years, respectively, which were born in consanguineous and Caucasian descent family.

https://doi.org/10.12691/ajmcr-10-4-3
Internal Medicine · 2025 · 0 citations · open access

Successful Treatment of 2-hydroxyglutaric Aciduria Diagnosed in Adulthood, Three Decades After the Onset: A Case Report and Literature Review

Abstract2-Hydroxyglutaric aciduria is a rare genetic metabolic disorder, especially in Japan. Although magnetic resonance images show characteristic abnormalities in the subcortical white matter, some cases have been diagnosed in adulthood, namely many decades after onset. We herein report the case of a bedridden 37-year-old 2-hydroxyglutaric aciduria male patient who was diagnosed three decades after onset. Despite this, combination treatment with riboflavin and levocarnitine improved his condition, thus allowing him to walk by himself. Considering our case and the previous literature, we emphasize the importance of correctly diagnosing and treating patients with 2-hydroxyglutaric aciduria.

https://doi.org/10.2169/internalmedicine.6360-25

Disease module: DeepOracle (Open Targets). Structures: RDKit from PubChem SMILES. Literature: retrieved by DeepSearch across 234,678,978 indexed works (targeted per-candidate search), resolved on OpenAlex.

DeCure is a research and publication project, not medical advice and not a treatment. "DeCure for X" describes a research goal, not a claim that a cure exists. Backing a cure is a contribution to fund the research — it is not an investment, and confers no yield, royalty, equity or IP ownership. Papers are published open-access by the DeCure.ai DAO.