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ORPHA:22

Succinic semialdehyde dehydrogenase deficiency

high confidenceDisorder

Also known as: 4-hydroxybutyric aciduria · Gamma-hydroxybutyric aciduria · SSADH deficiency

Publications

621

85.9th percentile

Trials

1

Interventional, condition-specific

Researchers

952

Distinct authors in sample

Gene link

ALDH5A1

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare neurometabolic disorder of gamma-aminobutyric acid (GABA) metabolism with a nonspecific clinical presentation (ranging from mild to severe) with the most frequent symptoms being cognitive impairment with prominent deficit in expressive language, , , , and behavioral dysregulation.

How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (2)

gamma-hydroxybutyric aciduria · succinic semialdehyde dehydrogenase deficiency

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

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

  1. Gene identifiedPresent

    Definitive — ALDH5A1

  2. LiteraturePresent

    621 matched papers (329 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPresent

    1 matched on ClinicalTrials.gov

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 (ALDH5A1).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

Not enriched in this build — Monarch phenotype joins were not run for this record.

Animal models (Monarch / Alliance)

Not enriched in this build.

Literature

Is anyone studying this?

621

621 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

621 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).

329 in the last 10 years · high confidence · 85.9th percentile (publications denominator)

Phrase hits: 621 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

952

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
    Gibson KM54 papers · 2024

    Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Neuroscience Campus, Amsterdam, The Netherlands.

    Papers in Europe PMC
  2. 02
    Pearl PL54 papers · 2026

    Department of Neurology, Children's National Medical Center, George Washington University School of Health Sciences, Washington, DC 20010-2970, USA. ppearl@cnmc.org

    Papers in Europe PMC
  3. 03
    Roullet JB35 papers · 2025

    Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Neuroscience Campus, Amsterdam, The Netherlands.

    Papers in Europe PMC
  4. 04
    Rotenberg A17 papers · 2026

    Neuromodulation Program, Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Boston Children's Hospital, Boston, MA, United States.

    Papers in Europe PMC
  5. 05
    Salomons GS17 papers · 2021

    Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Neuroscience Campus, Amsterdam, The Netherlands.

    Papers in Europe PMC
  6. 06
    Arning E14 papers · 2026

    Baylor Scott & White Research Institute, Institute of Metabolic Disease, Dallas, TX, USA.

    Papers in Europe PMC
  7. 07
    Bertoldi M14 papers · 2026

    Department of Neuroscience, Biomedicine and Movement, Section of Biological Chemistry, University of Verona, Strada Le Grazie, 8, 37134 Verona, Italy.

    Papers in Europe PMC
  8. 08
    DiBacco ML13 papers · 2025

    From the Department of Neurology (M.L.D., P.L.P.) and Neurodevelopmental Core (E.H.), Boston Children's Hospital, Harvard Medical School, MA; Metabolic Unit, Department of Clinical Chemistry, Vrije Universiteit Amsterdam (A.P., G.S.S.), and Department of Genetic Metabolic Diseases, Emma Children's Hospital, University of Amsterdam (G.S.S.), Amsterdam Neuroscience and Amsterdam Gastroenterology & Metabolism, Amsterdam University Medical Centers, the Netherlands; and College of Pharmacy, Department of Pharmacotherapy (J.-B.R., K.M.G.), Washington State University, Spokane.

    Papers in Europe PMC
  9. 09
    Tokatly Latzer I13 papers · 2025

    Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.

    Papers in Europe PMC
  10. 10
    Jakobs C12 papers · 2015

    From the Division of Neurology, Department of Medicine (S.L.-R., C.D.M., A.G.) and Department of Radiology (C.T.), The Ottawa Hospital, University of Ottawa, Ontario, Canada; Division of Neurology (E.C.L.) and Department of Pediatrics (P.C.), Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada; Division of Experimental and Systems Pharmacology (K.M.G.), Washington State University College of Pharmacy, Spokane, WA; Department of Clinical Chemistry (G.S.S., C.J.), Metabolic Unit, Polikliniek rec. K (PK 1X 009), VU University Medical Center, Amsterdam, the Netherlands; University of Ottawa Eye Institute (A.A.-R.), Ottawa, Ontario, Canada; and Department of Epilepsy & Clinical Neurophysiology (M.P., P.L.P.), Harvard Medical School, Boston Children's Hospital, Boston, MA. Dr. Lapalme-Remis is currently with the Mayo Clinic, Rochester, MN. Dr. Lewis is currently with The Hospital for Sick Children, Toronto, Ontario, Canada. Dr. Ali-Ridha is currently with McGill University, Montreal, Quebec, Canada.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

1

interventional trials for this specific condition

1 interventional trial matched this specific condition name; none in our sample are currently recruiting.

Data as of 27 July 2026

1 interventional trial — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 76.8th percentile).

high confidence · 76.8th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

No currently recruiting studies in the matched set. Open the same search on ClinicalTrials.gov.

Observational and natural-history studies

5 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

Where to find support

We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:

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.

"Succinic semialdehyde dehydrogenase deficiency" OR "4-hydroxybutyric aciduria" OR "Gamma-hydroxybutyric aciduria" OR "SSADH deficiency"

Run this search on Europe PMC

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

"Succinic semialdehyde dehydrogenase deficiency" OR "4-hydroxybutyric aciduria" OR "Gamma-hydroxybutyric aciduria" OR "SSADH deficiency" OR "ALDH5A1"

Recall-expansion terms: ALDH5A1

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: 1 interventional · 5 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion

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

Ingested 2026-07-26T12:07:35.139Z