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ORPHA:83418

Proximal spinal muscular atrophy type 2

medium confidenceSubtype of disorder

Also known as: Intermediate spinal muscular atrophy · SMA type 2 · SMA type II · SMA-II · SMA2

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

Publications

10,130

95.8th percentile

Trials

14

Interventional, condition-specific

Researchers

1,414

Distinct authors in sample

Gene link

SMN1

Strong

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A rare genetic motor neuron disorder characterized by degeneration of alpha motor neurons in the spinal cord and lower brainstem manifesting between 6 and 18 months of age with , predominantly proximal muscle weakness. Classically, before the introduction of disease-modifying therapies, patients with proximal spinal muscular atrophy (SMA) type 2 learned to sit, but never achieved independent ambulation.

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 (6)

chronic infantile spinal muscular atrophy · chronic spinal muscular atrophy · muscular atrophy, spinal, infantile chronic form · muscular atrophy, spinal, intermediate type · spinal muscular atrophy, type II · spinal muscular atrophy-2

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.”

5/6 stages with a signal

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

  1. Gene identifiedPresent

    Strong — SMN1

  2. LiteraturePresent

    10,130 matched papers (6,476 in last 10 years) Source

  3. Phenotype characterisedPresent

    8 HPO annotations (e.g. Skeletal muscle atrophy; Degeneration of anterior horn cells; Tongue fasciculations) Source

  4. Animal modelPresent

    1 genotype model (Mus musculus) Source

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPresent

    14 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 (SMN1).

GenCC classification: Strong.

Phenotypes (Monarch / HPO)

8

Associated phenotypes · MONDO:0009673

  • Skeletal muscle atrophy
  • Degeneration of anterior horn cells
  • Tongue fasciculations
  • Spinal muscular atrophy
  • EMG abnormality

Showing 5 of 8 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

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)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

10,130

10,130 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.

10,130 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).

6,476 in the last 10 years · medium confidence · 95.8th percentile (publications denominator)

Phrase hits: 1,795 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,414

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
    Coratti G11 papers · 2026

    Pediatric Neurology, Catholic University of Sacred Heart, Largo Gemelli 8, 00168, Rome, Italy.

    Papers in Europe PMC
  2. 02
    Mercuri E11 papers · 2026

    Pediatric Neurology, Catholic University of Sacred Heart, Largo Gemelli 8, 00168, Rome, Italy. eugeniomaria.mercuri@unicatt.it.

    Papers in Europe PMC
  3. 03
    Pane M10 papers · 2026

    Pediatric Neurology, Catholic University of Sacred Heart, Largo Gemelli 8, 00168, Rome, Italy.

    Papers in Europe PMC
  4. 04
    Pera MC9 papers · 2025

    Pediatric Neurology, Catholic University of Sacred Heart, Largo Gemelli 8, 00168, Rome, Italy.

    Papers in Europe PMC
  5. 05
    Albamonte E8 papers · 2026

    The NEMO Center in Milan, Neurorehabilitation Unit, University of Milan, ASST Niguarda Hospital, 20162 Milan, Italy.

    Papers in Europe PMC
  6. 06
    D'Amico A7 papers · 2025

    Unit of Neuromuscular and Neurodegenerative Disorders, Translational Paediatrics and Clinical Genetics, Bambino Gesù Children's Hospital, IRCCS 00165 Rome, Italy.

    Papers in Europe PMC
  7. 07
    Zhang Y7 papers · 2026

    Institute for Biomedicine and Glycomics, Griffith University, Brisbane, QLD 4111, Australia.

    Papers in Europe PMC
  8. 08
    Bruno C6 papers · 2025

    Center of Translational and Experimental Myology and Department of Neuroscience, Rehabilitation, Ophthalmology Genetics, Maternal and Child Health, IRCCS Istituto Giannina Gaslini and University of Genoa, 16132 Genoa, Italy.

    Papers in Europe PMC
  9. 09
    Darras BT6 papers · 2026

    Neuromuscular Program, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.

    Papers in Europe PMC
  10. 10
    Montes J6 papers · 2025

    Columbia University Irving Medical Center, New York, NY 10032, USA.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

14

interventional trials for this specific condition

14 interventional trials matched this specific condition name; none in our sample are currently recruiting.

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

14 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 93.7th percentile).

medium confidence · 93.7th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

14 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: proximal spinal muscular atrophy

0

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

Parent-category matching found a broader label but no interventional trials under it. How we count trials.

Observational and natural-history studies

3 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.

None of the matched observational studies is currently listed as 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 13 · after dedupe 13 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 13 · dropped 0 · fetched 2026-07-30

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 (13)

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 Proximal spinal muscular atrophy type 2 — check Associations / patient organisations on that page.

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.

("Proximal spinal muscular atrophy type 2" OR "Intermediate spinal muscular atrophy" OR "SMA type 2" OR "SMA type II" OR "SMA-II" OR "chronic infantile spinal muscular atrophy" OR "chronic spinal muscular atrophy" OR "muscular atrophy, spinal, infantile chronic form" OR "muscular atrophy, spinal, intermediate type" OR "spinal muscular atrophy, type II" OR "spinal muscular atrophy-2") OR (MESH:"[OBSOLETE] Muscular atrophy, spinal, infantile chronic form") OR ("SMN1" OR "SMN1 syndrome" OR "SMN1-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: [OBSOLETE] Muscular atrophy, spinal, infantile chronic form

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

"Proximal spinal muscular atrophy type 2" OR "Intermediate spinal muscular atrophy" OR "SMA type 2" OR "SMA type II" OR "SMA-II" OR "chronic infantile spinal muscular atrophy" OR "chronic spinal muscular atrophy" OR "muscular atrophy, spinal, infantile chronic form" OR "muscular atrophy, spinal, intermediate type" OR "spinal muscular atrophy, type II" OR "spinal muscular atrophy-2" OR "[OBSOLETE] Muscular atrophy, spinal, infantile chronic form"

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: 14 interventional · 3 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"proximal spinal muscular atrophy"

Query health: suspect — strategies attempted: phrase, mesh; with hits: phrase

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: SMA2

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 2026-07-27T02:34:54.044Z