ORPHA:401805

Autosomal recessive spastic paraplegia type 63

high confidenceDisorder

Also known as: SPG63

Publications

37.8th percentile

Trials

Interventional, condition-specific

Researchers

230

Distinct authors in sample

Gene link

AMPD2

Limited

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

spastic paraplegia type 63 (SPG63) is an extremely rare and complex form of spastic paraplegia characterized by an onset in infancy of spastic paraplegia (presenting with delayed walking and a scissors gait) associated with short stature, and normal cognition. Periventricular deep white matter changes in the corpus callosum are noted on brain imaging. SPG63 is caused by a homozygous mutation in the AMPD2 gene (1p13.3) encoding AMP deaminase 2.

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 (3)

AMPD2 autosomal recessive complex spastic paraplegia · autosomal recessive complex spastic paraplegia caused by mutation in AMPD2 · hereditary spastic paraplegia type 63

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.

Gene identifiedPresent
Limited — AMPD2
LiteraturePresent
26 matched papers (21 in last 10 years) Source
Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
Animal modelNot checked
Not yet enriched from Monarch / Alliance
Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
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?

Possibly — only limited evidence so far for AMPD2.

GenCC classification: Limited.

AMPD2

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?

26 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.

26 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).

21 in the last 10 years · high confidence · 37.8th percentile (publications denominator)

Phrase hits: 26 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

230

Distinct author names in 26 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.

01
Stevanin G3 papers · 2021
Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225; UPMC Univ Paris VI UMR_S975, 75013 Paris, France.
Papers in Europe PMC
02
Koh K2 papers · 2020
Department of Clinical Research (Y.O., M. Yoshita), National Hospital Organization, Hokuriku National Hospital, Nanto; Department of Neurology (K.K., Y.T.), Graduate School of Medical Science, University of Yamanashi, Tyuo; Department of Neurology (H.I.), The University of Tokyo; Department of Molecular Neurology (S.T.), Graduate School of Medicine, The University of Tokyo; Institute of Medical Genomics (S.T.), International University of Health and Welfare, Chiba; and Department of Neurology and Neurobiology of Aging (M. Yamada), Kanazawa University Graduate School of Medical Sciences, Japan.
Papers in Europe PMC
03
Leventer RJ2 papers · 2019
Bruce Lefroy Centre for Genetic Health Research (A.P.L.M., K.P., E.M.Y., J.C.H.S., M.B.D., P.J.L.), Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Australia; Bioinformatics Division (V.L., C.B., R.T., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Neurology (M.M.R., E.M.Y., R.J.L.) and Department of Paediatrics (A.P.L.M., M.M.R., E.M.Y., M.B.D., D.J.A., R.J.L., P.J.L.), The University of Melbourne, Royal Children's Hospital, Parkville, Australia; Victorian Clinical Genetics Services (D.J.A., G.M.) and Neuroscience Research (M.M.R., R.J.L.), Murdoch Childrens Research Institute, Parkville, Australia; Department of Neurology (E.H.S.), UCSF Benioff Children's Hospital, San Francisco, CA; Clinical Genetics (M.B.D.), Austin Health, Heidelberg, Australia; and Department of Mathematics and Statistics (M.B.) and Department of Medical Biology (R.T., M.B.), The University of Melbourne, Parkville, Australia.
Papers in Europe PMC
04
Lockhart PJ2 papers · 2019
Bruce Lefroy Centre for Genetic Health Research (A.P.L.M., K.P., E.M.Y., J.C.H.S., M.B.D., P.J.L.), Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Australia; Bioinformatics Division (V.L., C.B., R.T., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Neurology (M.M.R., E.M.Y., R.J.L.) and Department of Paediatrics (A.P.L.M., M.M.R., E.M.Y., M.B.D., D.J.A., R.J.L., P.J.L.), The University of Melbourne, Royal Children's Hospital, Parkville, Australia; Victorian Clinical Genetics Services (D.J.A., G.M.) and Neuroscience Research (M.M.R., R.J.L.), Murdoch Childrens Research Institute, Parkville, Australia; Department of Neurology (E.H.S.), UCSF Benioff Children's Hospital, San Francisco, CA; Clinical Genetics (M.B.D.), Austin Health, Heidelberg, Australia; and Department of Mathematics and Statistics (M.B.) and Department of Medical Biology (R.T., M.B.), The University of Melbourne, Parkville, Australia.
Papers in Europe PMC
05
Novarino G2 papers · 2019
Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093, USA.
Papers in Europe PMC
06
Shi Y2 papers · 2025
Xi'an Medical University, Xi'an, 710021, People's Republic of China.
Papers in Europe PMC
07
Takiyama Y2 papers · 2020
Department of Clinical Research (Y.O., M. Yoshita), National Hospital Organization, Hokuriku National Hospital, Nanto; Department of Neurology (K.K., Y.T.), Graduate School of Medical Science, University of Yamanashi, Tyuo; Department of Neurology (H.I.), The University of Tokyo; Department of Molecular Neurology (S.T.), Graduate School of Medicine, The University of Tokyo; Institute of Medical Genomics (S.T.), International University of Health and Welfare, Chiba; and Department of Neurology and Neurobiology of Aging (M. Yamada), Kanazawa University Graduate School of Medical Sciences, Japan.
Papers in Europe PMC
08
Zaki MS2 papers · 2022
Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Center, Cairo 12311, Egypt.
Papers in Europe PMC
09
Abbaszadegan MR1 paper · 2022
Medical Genetics Research Center, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran.
Papers in Europe PMC
10
Abdel-Salam GMH1 paper · 2014
Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Center, Cairo 12311, Egypt.
Papers in Europe PMC

Clinical research

Is a treatment being tested?

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

1 observational study matches 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

NCT06092346·RECRUITING·A Natural History Study Seeks to Understand the Clinical, Genomic, Pharmacological, Laboratory, and Dietary Determinates of Pyrimidine and Purine Metabolism Disorders
Conditions: AMPD3, OMIM*102772, AMP Deaminase Deficiency · AK1, OMIM *103000, Adenylate Kinase Deficiency · AMPD1, OMIM *102770, Myopathy Due to Myoadenylate Deaminase Deficiency · TPMT, OMIM *187680, Thoipurines, Poor Metabolism of·Matched via recall expansion

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.

"Autosomal recessive spastic paraplegia type 63" OR "SPG63" OR "AMPD2 autosomal recessive complex spastic paraplegia" OR "autosomal recessive complex spastic paraplegia caused by mutation in AMPD2" OR "hereditary spastic paraplegia type 63"

Run this search on Europe PMC

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

"Autosomal recessive spastic paraplegia type 63" OR "SPG63" OR "AMPD2 autosomal recessive complex spastic paraplegia" OR "autosomal recessive complex spastic paraplegia caused by mutation in AMPD2" OR "hereditary spastic paraplegia type 63" OR "AMPD2"

Recall-expansion terms: AMPD2

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 · 1 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 2026-07-27T15:25:09.598Z