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ORPHA:139441

Hypomyelination with atrophy of basal ganglia and cerebellum

medium confidenceDisorder

Also known as: H-ABC

Publications

472

83.7th percentile

Trials

2

Interventional, condition-specific

Researchers

1,307

Distinct authors in sample

Gene link

TUBB4A

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare disorder characterized by slowly spasticity, extrapyramidal movement disorders (dystonia, choreoathetosis and rigidity), cerebellar , moderate to severe cognitive deficit, and anarthria/dysarthria. Patients present with distinctive MRI findings of diffuse hypomyelination of the cerebral hemispheres, mild to severe cerebellar atrophy, and atrophy of the basal nuclei.

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.

Additional Mondo synonyms (5)

HABC · HLD6 · hypomyelinating leukodystrophy type 6 · hypomyelination with atrophy of basal ganglia and cerebellum · leukodystrophy, hypomyelinating, type 6

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 — TUBB4A

  2. LiteraturePresent

    472 matched papers (278 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

    2 matched on ClinicalTrials.gov (1 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 (TUBB4A).

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?

472

472 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=5449) is 41.

472 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).

278 in the last 10 years · medium confidence · 83.7th percentile (publications denominator)

Phrase hits: 472 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,307

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
    van der Knaap MS22 papers · 2025

    Department of Child Neurology, VU University Medical Center and Neuroscience Campus Amsterdam, Amsterdam, the Netherlands.

    Papers in Europe PMC
  2. 02
    Vanderver A20 papers · 2026

    Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.

    Papers in Europe PMC
  3. 03
    Wolf NI15 papers · 2025

    Department of Child Neurology, Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers, and Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Vrije Universiteit, Amsterdam, Netherlands.

    Papers in Europe PMC
  4. 04
    Bernard G13 papers · 2026

    Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada genevieve.bernard@mcgill.ca.

    Papers in Europe PMC
  5. 05
    Eguibar JR11 papers · 2026

    Institute of Physiology, Av. 14 Sur # 6301. Col. Jardínes de San Manuel, Puebla, Pue. C.P. 72570, Mexico; International Office, Benemérita Universidad Autónoma de Puebla. Torre de Gestión Académica y Servicios Administrativos, 3(er) piso. Col. Jardínes de San Manuel, Puebla, Pue. C.P. 72570, Mexico. Electronic address: jose.eguibar@correo.buap.mx.

    Papers in Europe PMC
  6. 06
    Cortes C10 papers · 2026

    Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, México.

    Papers in Europe PMC
  7. 07
    Schiffmann R9 papers · 2017

    Institute for Metabolic Disease, Baylor Research Institute, Dallas, TX.

    Papers in Europe PMC
  8. 08
    Simons C9 papers · 2025

    Institute for Molecular Bioscience, The University of Queensland, St Lucia, Australia.

    Papers in Europe PMC
  9. 09
    Takanohashi A8 papers · 2026

    Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC.

    Papers in Europe PMC
  10. 10
    Hernandez VH7 papers · 2026

    Departament of Chemical, Electronic and Biomedical Engineering, DCI, University of Guanajuato, Guanajuato, Mexico.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

2

interventional trials for this specific condition

2 interventional trials matched this specific condition name; 1 currently recruiting in our sample.

Data as of 27 July 2026

2 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 82.4th percentile).

medium confidence · 82.4th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Observational and natural-history studies

2 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.

"Hypomyelination with atrophy of basal ganglia and cerebellum" OR "Hypomyelination with atrophy of the basal ganglia and cerebellum" OR "H-ABC" OR "hypomyelinating leukodystrophy type 6" OR "leukodystrophy, hypomyelinating, type 6"

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Leukodystrophy, Hypomyelinating, 6

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

"Hypomyelination with atrophy of basal ganglia and cerebellum" OR "Hypomyelination with atrophy of the basal ganglia and cerebellum" OR "H-ABC" OR "hypomyelinating leukodystrophy type 6" OR "leukodystrophy, hypomyelinating, type 6" OR "Leukodystrophy, Hypomyelinating, 6" OR "TUBB4A"

Recall-expansion terms: TUBB4A

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

Study-type breakdown: 2 interventional · 2 observational · 0 expanded access. Only interventional studies enter the trial headline.

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: HABC; HLD6

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 2 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T07:36:18.932Z