RARE DISEASERESEARCH ATLAS
Open navigation menu

ORPHA:139557

X-linked distal spinal muscular atrophy type 3

high confidenceDisorder

Also known as: ATP7A-related distal motor neuropathy · DSMAX · SMAX3 · X-linked dHMN3 · X-linked dSMA3 · X-linked distal hereditary motor neuropathy type 3

Publications

168

70.2th percentile

Trials

1

Interventional, condition-specific

Researchers

934

Distinct authors in sample

Gene link

ATP7A

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

X-linked distal spinal muscular atrophy type 3 is a rare distal motor characterized by slowly atrophy and weakness of distal muscles of hands and feet with normal deep tendon reflexes or absent ankle reflexes and minimal or no sensory loss, sometimes mild proximal weakness in the legs and feet and hand deformities in males.

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 (6)

ATP7A spinal muscular atrophy · X-linked dHMN type 3 · X-linked dSMA type 3 · spinal muscular atrophy caused by mutation in ATP7A · spinal muscular atrophy, distal, X-linked 3, X-linked recessive · spinal muscular atrophy, distal, X-linked type 3

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 — ATP7A

  2. LiteraturePresent

    168 matched papers (125 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 (ATP7A).

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?

168

168 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.

168 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).

125 in the last 10 years · high confidence · 70.2th percentile (publications denominator)

Phrase hits: 168 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

934

Distinct author names in 168 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
    Kaler SG13 papers · 2020

    Unit on Human Copper Metabolism, Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1853, USA. kalers@mail.nih.gov

    Papers in Europe PMC
  2. 02
    Wang Y6 papers · 2025

    Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA.

    Papers in Europe PMC
  3. 03
    Yi L6 papers · 2021

    China Water Resources Pearl River Planning, Surveying & Designing Co., Ltd., Zhanyi Road 19#, Guangzhou, 510610, China.

    Papers in Europe PMC
  4. 04
    Donsante A5 papers · 2012

    Unit on Human Copper Metabolism, Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1853, USA.

    Papers in Europe PMC
  5. 05
    Faundez V5 papers · 2025

    Departments of Cell Biology, Emory University, Atlanta, United States.

    Papers in Europe PMC
  6. 06
    Petris MJ5 papers · 2021

    Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.

    Papers in Europe PMC
  7. 07
    Celiński M4 papers · 2022

    Central Institute for Labour Protection-National Research Institute, Department of Chemical, Biological and Aerosol Hazards, 00-701 Warsaw, Poland.

    Papers in Europe PMC
  8. 08
    Kozikowski P4 papers · 2022

    Central Institute for Labour Protection-National Research Institute, Department of Chemical, Biological and Aerosol Hazards, 00-701 Warsaw, Poland.

    Papers in Europe PMC
  9. 09
    Møller LB4 papers · 2023

    Kennedy Centre, Glostrup, Denmark.

    Papers in Europe PMC
  10. 10
    Sałasińska K4 papers · 2022

    Central Institute for Labour Protection-National Research Institute, Department of Chemical, Biological and Aerosol Hazards, 00-701 Warsaw, Poland.

    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. 166 trials are registered for spinal muscular atrophy, the broader category — shown separately because they may or may not enrol this specific subtype.

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.

Broader category: spinal muscular atrophy

166

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

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

Likely covered — the policy lists Spinal muscular atrophy as a category (Group 3), and this condition is a form of it. Confirm eligibility with a Centre of Excellence.

Group 3 — high-cost / lifelong therapy with careful selection

Up to ₹50 lakh per patient

Financial support at notified Centres of Excellence is the figure commonly cited in recent MoHFW/PIB statements. Many Group 3 patients also use the MoHFW voluntary-contribution / crowdfunding portal.

Eligibility and patient selection rules change. Verify with a CoE; the crowdfunding portal is a separate mechanism from CoE funding. 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.

"X-linked distal spinal muscular atrophy type 3" OR "ATP7A-related distal motor neuropathy" OR "DSMAX" OR "SMAX3" OR "X-linked dHMN3" OR "X-linked dSMA3" OR "X-linked distal hereditary motor neuropathy type 3" OR "ATP7A spinal muscular atrophy" OR "X-linked dHMN type 3" OR "X-linked dSMA type 3" OR "spinal muscular atrophy caused by mutation in ATP7A" OR "spinal muscular atrophy, distal, X-linked 3, X-linked recessive" OR "spinal muscular atrophy, distal, X-linked type 3"

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Spinal Muscular Atrophy, Distal, X-Linked 3

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

"X-linked distal spinal muscular atrophy type 3" OR "ATP7A-related distal motor neuropathy" OR "DSMAX" OR "SMAX3" OR "X-linked dHMN3" OR "X-linked dSMA3" OR "X-linked distal hereditary motor neuropathy type 3" OR "ATP7A spinal muscular atrophy" OR "X-linked dHMN type 3" OR "X-linked dSMA type 3" OR "spinal muscular atrophy caused by mutation in ATP7A" OR "spinal muscular atrophy, distal, X-linked 3, X-linked recessive" OR "spinal muscular atrophy, distal, X-linked type 3" OR "Spinal Muscular Atrophy, Distal, X-Linked 3" OR "ATP7A"

Recall-expansion terms: ATP7A

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

Parent-category trials query:

"spinal muscular atrophy"

Query health: ok — strategies attempted: phrase, mesh, 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 2026-07-27T07:40:38.923Z