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ORPHA:716

Phenylketonuria

low confidenceDisorder

Also known as: PKU

Publications

18,012

Trials

93

Interventional, condition-specific

Researchers

1,309

Distinct authors in sample

Gene link

PAH

Definitive

Readiness

6/6

Stages with a signal

Clinical definition (Orphanet)

A rare inborn error of amino acid metabolism characterized by elevated blood phenylalanine and low levels or absence of phenylalanine hydroxylase . If not detected early or left untreated, the disorder manifests with mild to severe mental disability.

How rare: 1-9 / 100 000 — about one to nine people per hundred thousand.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (4)

PAH deficiency · hyperphenylalaninemia, non-PKU mild · phenylalanine hydroxylase deficiency · phenylketonuria

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.”

6/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Definitive — PAH

  2. LiteraturePresent

    18,012 matched papers (7,658 in last 10 years) Source

  3. Phenotype characterisedPresent

    84 HPO annotations (e.g. Eczematoid dermatitis; Hypopigmentation of the skin; Seizure) Source

  4. Animal modelPresent

    7 genotype models (Mus musculus) Source

  5. Orphan designationPartial

    3 EMA designations (none yet with FDA orphan-indication approval) — e.g. adeno-associated virus vector encoding human phenylalanine hydroxylase Source

  6. Interventional trialPresent

    93 matched on ClinicalTrials.gov (19 recruiting in sample)

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 (PAH).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

84

Associated phenotypes · MONDO:0009861

  • Eczematoid dermatitis
  • Hypopigmentation of the skin
  • Seizure
  • Abnormal cerebral white matter morphology
  • Musty odor

Showing 5 of 84 — open Monarch for the full list.

Animal models (Monarch / Alliance)

7

Model associations linked to this Mondo ID

Monarch fetch 2026-07-29

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)

3

Designations · no FDA orphan-indication approval yet

  • EMA adeno-associated virus vector encoding human phenylalanine hydroxylaseTreatment of phenylalanine hydroxylase deficiency · 16/12/2019 · WithdrawnEMA designation
  • EMA adeno-associated virus serotype HSC15, containing human homology arms, expressing human phenylalanine hydroxylaseTreatment of phenylalanine hydroxylase deficiency · 16/03/2022 · WithdrawnEMA designation
  • EMA adeno-associated virus serotype HSC15 expressing human phenylalanine hydroxylaseTreatment of phenylalanine hydroxylase deficiency · 14/12/2018 · WithdrawnEMA designation

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

8

Drugs / clinical candidates · MONDO_0009861

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

18,012

18,012 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

18,012 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).

7,658 in the last 10 years · low confidence

Phrase hits: 16,470 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,309

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    MacDonald A8 papers · 2026

    Dietetic Department, Birmingham Children's Hospital, Birmingham B4 6NH, UK. Electronic address: Anita.Macdonald@nhs.net.

    Papers in Europe PMC
  2. 02
    Harding CO7 papers · 2026

    Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA.

    Papers in Europe PMC
  3. 03
    Longo N6 papers · 2026

    Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, USA.

    Papers in Europe PMC
  4. 04
    Maillot F6 papers · 2026

    Department of Internal Medicine, INSERM 1253 "iBraiN", University of Tours, Tours, France.

    Papers in Europe PMC
  5. 05
    Muntau AC6 papers · 2026

    University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

    Papers in Europe PMC
  6. 06
    Pinto A6 papers · 2026

    Dietetic Department, Birmingham Children's Hospital, Birmingham B4 6NH, UK. Electronic address: Alex.Pinto@nhs.net.

    Papers in Europe PMC
  7. 07
    van Spronsen FJ6 papers · 2026

    Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9700 RB Groningen, The Netherlands.

    Papers in Europe PMC
  8. 08
    Walkowiak D6 papers · 2026

    Poznan University of Medical Sciences, Department of Organization and Management in Health Care, Marii Magdaleny Str. 14, 61-861 Poznań, Poland.

    Papers in Europe PMC
  9. 09
    Ashmore C5 papers · 2026

    Birmingham Children's Hospital, Steelhouse Lane, Birmingham B4 6NH, UK.

    Papers in Europe PMC
  10. 10
    Daly A5 papers · 2026

    Birmingham Children's Hospital, Steelhouse Lane, Birmingham B4 6NH, UK.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

93

interventional trials for this specific condition

93 interventional trials matched this specific condition name; 19 currently recruiting in our sample.

Data as of 11 September 2026 · last trial check 28 July 2026

93 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 98.4th percentile).

low confidence · 98.4th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

93 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

51 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

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 31 · after dedupe 29 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 29 · dropped 0 · fetched 2026-07-29

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).

Uncertain / not reviewed (29)

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 Phenylketonuria — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

Directly listed under NPRD Group 2.

Group 2 — long-term / lifelong lower-cost interventions

NPRD envisages State Government support for dietary formulae, hormones, and other lower-cost interventions. This is a different route from the central CoE ₹50 lakh pathway; ask your state health department and a CoE which channel applies.

Central CoE funding may also apply depending on current rules — confirm with a notified Centre of Excellence. Do not assume the ₹50 lakh ceiling covers Group 2 by default. Verify

Centres of Excellence (15)
  • All India Institute of Medical Sciences (AIIMS) — New Delhi, Delhi
  • Maulana Azad Medical College — New Delhi, Delhi
  • Sanjay Gandhi Post Graduate Institute of Medical Sciences — Lucknow, Uttar Pradesh
  • Post Graduate Institute of Medical Education and Research (PGIMER) — Chandigarh, Chandigarh
  • Centre for DNA Fingerprinting & Diagnostics with Nizam’s Institute of Medical Sciences — Hyderabad, Telangana
  • King Edward Memorial Hospital — Mumbai, Maharashtra
  • Institute of Post-Graduate Medical Education and Research (IPGMER) — Kolkata, West Bengal
  • Centre for Human Genetics with Indira Gandhi Hospital — Bengaluru, Karnataka
  • Institute of Child Health and Hospital for Children (ICH & HC) — Chennai, Tamil Nadu
  • All India Institute of Medical Sciences (AIIMS) — Jodhpur, Rajasthan
  • Sree Avittam Thirunal Hospital (SAT), Government Medical College — Thiruvananthapuram, Kerala
  • All India Institute of Medical Sciences (AIIMS) — Bhopal, Madhya Pradesh
  • Regional Institute of Medical Sciences (RIMS) — Imphal, Manipur
  • All India Institute of Medical Sciences (AIIMS) — Patna, Bihar
  • Assam Medical College & Hospital — Dibrugarh, Assam

Voluntary contributions / crowdfunding (separate from CoE funding): https://rarediseases.mohfw.gov.in/

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.

("Phenylketonuria" OR "PAH deficiency" OR "hyperphenylalaninemia, non-PKU mild" OR "phenylalanine hydroxylase deficiency") OR ("PAH syndrome" OR "PAH-related")

Run this search on Europe PMC

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

"Phenylketonuria" OR "PAH deficiency" OR "hyperphenylalaninemia, non-PKU mild" OR "phenylalanine hydroxylase deficiency"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 93 interventional · 51 observational · 1 expanded access. Only interventional studies enter the trial headline.

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: PKU

Confidence reasoning

  • Preferred label is short or not clearly distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T15:01:19.825Z