RARE DISEASERESEARCH ATLAS
Open navigation menu

ORPHA:512

Metachromatic leukodystrophy

medium confidenceDisorder

Also known as: Arylsulfatase A deficiency · MLD

Query health: suspect — Only one of 2 strategies returned hits (phrase).

Publications

4,027

95.4th percentile

Trials

23

Interventional, condition-specific

Researchers

1,336

Distinct authors in sample

Gene link

ARSA

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare lysosomal disease characterized by accumulation of sulfatides in the central and peripheral nervous system due to deficiency of the arylsulfatase A, leading to demyelination. Three clinical subtypes can be distinguished based on the age of onset: late , juvenile, and adult. Lead symptoms are deterioration in motor or cognitive function or behavioral problems, depending on the subtype, all eventually culminating in a decerebrated state and death after a highly variable disease course and duration. Mode of inheritance is .

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 (1)

arylsulfatase A 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 — ARSA

  2. LiteraturePresent

    4,027 matched papers (1,847 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

    23 matched on ClinicalTrials.gov (2 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 (ARSA).

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?

4,027

4,027 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.

4,027 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).

1,847 in the last 10 years · medium confidence · 95.4th percentile (publications denominator)

Phrase hits: 4,027 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,336

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
    Groeschel S17 papers · 2026

    Department of Neuropediatrics, Developmental Neurology and Social Pediatrics University of Tuebingen Tuebingen Germany.

    Papers in Europe PMC
  2. 02
    Wolf NI17 papers · 2026

    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
  3. 03
    Adang LA13 papers · 2026

    Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA. Electronic address: adangl@chop.edu.

    Papers in Europe PMC
  4. 04
    Fumagalli F12 papers · 2026

    Ospedale San Raffaele, Via Olgettina 60, Milano 20132, Italy. Electronic address: fumagalli.francesca@hsr.it.

    Papers in Europe PMC
  5. 05
    Laugwitz L12 papers · 2026

    Department of Neuropediatrics, Developmental Neurology and Social Pediatrics University of Tuebingen Tuebingen Germany.

    Papers in Europe PMC
  6. 06
    van der Knaap MS12 papers · 2026

    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
  7. 07
    Sevin C10 papers · 2026

    Reference Center for Leukodystrophies, Pediatric Neurology Department, Hôpital Bicêtre, Le Kremlin Bicêtre, France.

    Papers in Europe PMC
  8. 08
    Calbi V9 papers · 2026

    San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), Pediatric Immunohematology Unit and Neurology and Neurophysiology Unit, IRCCS San Raffaele Scientific Institute, Via Olgettina, 60, 20132, Milan, Italy.

    Papers in Europe PMC
  9. 09
    Sevagamoorthy A9 papers · 2026

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

    Papers in Europe PMC
  10. 10
    Vanderver A9 papers · 2026

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

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

23

interventional trials for this specific condition

23 interventional trials matched this specific condition name; 2 currently recruiting in our sample. 8 trials are registered for leukodystrophy, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 27 July 2026

23 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 94.9th percentile).

medium confidence · 94.9th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Broader category: leukodystrophy

8

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

12 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

General rare disease registries you may be eligible for

These studies enroll across many rare conditions. They are not counted as evidence that anyone is studying this specific disease.

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.

"Metachromatic leukodystrophy" OR "Arylsulfatase A deficiency"

Run this search on Europe PMC

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

"Metachromatic leukodystrophy" OR "Arylsulfatase A deficiency" OR "ARSA"

Recall-expansion terms: ARSA

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: 23 interventional · 12 observational · 3 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"leukodystrophy"

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: MLD

Confidence reasoning

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

Ingested 2026-07-26T14:07:44.793Z