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ORPHA:555407

NAD(P)HX epimerase deficiency

medium confidenceDisorder

Also known as: Apolipoprotein A-I binding protein deficiency

Publications

215

67.5th percentile

Trials

0

Interventional, condition-specific

Researchers

41

Distinct authors in sample

Gene link

NAXE

Strong

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare neurometabolic disease characterized by onset of rapidly neurological deterioration, typically precipitated by a febrile illness. Patients present with , loss of previously acquired motor milestones and cognitive skills, , nystagmus, tremor, , tetraparesis, and respiratory failure, eventually resulting in a vegetative state. Imaging of the brain and spinal cord may show white matter abnormalities, cerebral atrophy, cerebellar edema, and spinal myelopathy. Subacute development of extensive bullous skin lesions within weeks of onset of neurological symptoms has also been reported.

How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

3/6 stages with a signal

No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.

  1. Gene identifiedPresent

    Strong — NAXE

  2. LiteraturePresent

    215 matched papers (191 in last 10 years) Source

  3. Phenotype characterisedPresent

    37 HPO annotations (e.g. Encephalopathy; Strabismus; Rigidity) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialNot found

    No matched interventional trial under our ClinicalTrials.gov rules

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Yes — we know a specific gene responsible (NAXE).

GenCC classification: Strong.

Phenotypes (Monarch / HPO)

37

Associated phenotypes · MONDO:0020781

  • Encephalopathy
  • Strabismus
  • Rigidity
  • Hypotonia
  • Respiratory failure

Showing 5 of 37 — open Monarch for the full list.

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-27

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

215

215 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

215 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

191 in the last 10 years · medium confidence · 67.5th percentile (publications denominator)

Phrase hits: 5 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

41

Distinct author names in 5 sampled papers — named people below.

Who's working on it?

No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.

  1. 01
    Ferreira CR2 papers · 2022

    National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.

    Papers in Europe PMC
  2. 02
    van Karnebeek CDM2 papers · 2022

    Department of Pediatrics, Amsterdam UMC, Amsterdam, The Netherlands. clara.vankarnebeek@radboudumc.nl.

    Papers in Europe PMC
  3. 03
    Achouri Y1 paper · 2019

    Groupe de Recherches Metaboliques, de Duve Institute, UCLouvain (Université Catholique de Louvain), B-1200 Brussels, Belgium.

    Papers in Europe PMC
  4. 04
    Bommer GT1 paper · 2019

    Walloon Excellence in Lifesciences and Biotechnology, B-1200 Brussels, Belgium.

    Papers in Europe PMC
  5. 05
    Carninci P1 paper · 2024

    Laboratory for Transcriptome Technology, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.

    Papers in Europe PMC
  6. 06
    Chevalier N1 paper · 2019

    Walloon Excellence in Lifesciences and Biotechnology, B-1200 Brussels, Belgium.

    Papers in Europe PMC
  7. 07
    Defour JP1 paper · 2019

    Groupe de Recherches Metaboliques, de Duve Institute, UCLouvain (Université Catholique de Louvain), B-1200 Brussels, Belgium.

    Papers in Europe PMC
  8. 08
    Dewulf JP1 paper · 2019

    Walloon Excellence in Lifesciences and Biotechnology, B-1200 Brussels, Belgium.

    Papers in Europe PMC
  9. 09
    Ferster A1 paper · 2019

    Department of Hematology/Oncology, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, B-1020 Brussels, Belgium.

    Papers in Europe PMC
  10. 10
    Fukunaga M1 paper · 2024

    Laboratory for Comprehensive Genomic Analysis, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

0

interventional trials for this specific condition

No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).

Data as of 9 September 2026 · last trial check 9 September 2026

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

medium confidence · 38.6th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.

See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-27

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for NAD(P)HX epimerase deficiency — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

("NAD(P)HX epimerase deficiency" OR "Apolipoprotein A-I binding protein deficiency") OR ("NAXE" OR "NAXE syndrome" OR "NAXE-related")

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"NAD(P)HX epimerase deficiency" OR "Apolipoprotein A-I binding protein deficiency"

Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (215) is high for prevalence class "<1 / 1 000 000" — confidence capped at medium

Ingested 2026-07-26T02:05:09.439Z