Arthrogryposis Multiplex Congenita

Complex MONDO:0015168 Pathograph 13 Show in embeddings browser Congenital Disorder

Arthrogryposis multiplex congenita (AMC) is a descriptive congenital phenotype and clinical syndrome, not a single etiologic disease. It is defined by congenital contractures affecting at least two different body regions. The distribution, associated anomalies, functional consequences, underlying cause, and recurrence risk vary widely. Etiologies can involve the central or peripheral nervous system, neuromuscular junction, muscle, connective or skeletal tissue, or the intrauterine environment. Reduced fetal movement is a well-supported route to contracture formation in some etiologic branches, but it is not modeled here as a proven universal cause.

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2
Definitions
4
Pathophys.
5
Phenotypes
3
Gaps
13
Pathograph
5
Medical Actions
3
Subtypes
3
Differentials
1
Datasets
2
Models
11
References
1
Deep Research
📘

Definitions

2
Multi-region congenital contracture definition
AMC is identified clinically when congenital joint contractures involve two or more different body regions. This definition identifies a phenotype for etiologic investigation; it does not assign a gene, inheritance mode, or mechanism.
OTHER
Show evidence (1 reference)
PMID:38856159 SUPPORT Human Clinical
"Arthrogryposis is a clinical feature defined by congenital joint contractures in two or more different body areas"
The clinical genetics report states the phenotype-level inclusion definition without treating arthrogryposis as one molecular disorder.
Etiologically heterogeneous clinical-syndrome definition
AMC is an etiologically heterogeneous clinical syndrome. A complete diagnosis therefore includes both recognition of the contracture phenotype and an attempt to determine the underlying disorder or exposure.
OTHER
Show evidence (2 references)
PMID:40947408 SUPPORT Other
"Arthrogryposis multiplex congenita (AMC) is a clinical syndrome with complex etiology."
The multidisciplinary consensus explicitly distinguishes the clinical syndrome from its many possible etiologies.
PMID:40195522 SUPPORT Human Clinical
"Arthrogryposis multiplex congenita (AMC) presents challenges for prenatal detection due to its heterogeneous etiology, onset, and phenotypical manifestations."
The consecutive fetal cohort independently supports heterogeneity of cause, onset, and presentation.
◆

Subtypes

3
Amyoplasia MONDO:0044629
Amyoplasia is a recognized clinical pattern within AMC, with characteristic limb positions and fatty-fibrous replacement of affected muscle. Its sporadic occurrence is a property of Amyoplasia, not an inheritance rule for the AMC umbrella.
Show evidence (1 reference)
PMID:24459070 SUPPORT Human Clinical
"Affected limbs had characteristic positions with fatty-fibrous replacement of muscle."
The 560-person Amyoplasia series supports this pattern-specific tissue and limb-position phenotype.
Distal arthrogryposis MONDO:0019942
Distal arthrogryposis is a group of etiologic diagnoses in which distal joints are emphasized and proximal involvement is generally less extensive. Molecular and inheritance findings for individual distal arthrogryposis disorders must not be generalized to all AMC.
Show evidence (1 reference)
PMID:33104047 SUPPORT Human Clinical
"Children with DA had less involvement of the proximal joints than those in the two other groups."
The pediatric cohort supports distal arthrogryposis as a clinically distinguishable distribution pattern.
Central nervous system, neuromuscular, and syndromic patterns
AMC may accompany central nervous system, peripheral neuromuscular, or multisystem disorders. This is an etiologic-work-up grouping rather than a single formal subtype, and associated prognosis is determined by the underlying diagnosis.
Show evidence (1 reference)
PMID:40947408 SUPPORT Other
"AMC may be divided into amyoplasia, distal arthrogryposis, central nervous system and neuromuscular diseases"
The consensus uses these groups to organize diagnostic evaluation while retaining AMC as a complex clinical syndrome.
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Discussions and Knowledge Gaps

3
Should AMC be modeled as one genetic disease with a shared inheritance and gene list, or as a descriptive phenotype that triggers etiologic work-up?
INTERPRETATION RESOLVED interpretation_amc_is_a_descriptive_umbrella
Attached to
definitions#Multi-region congenital contracture definition definitions#Etiologically heterogeneous clinical-syndrome definition diagnosis#Etiology-directed cytogenomic and sequencing tests
The defining criterion is phenotypic, authoritative consensus describes a clinical syndrome with complex etiology, and fetal cohorts resolve different chromosomal and sequence diagnoses in only subsets. This entry therefore intentionally omits umbrella-level inheritance and gene assertions.
Show evidence (2 references)
PMID:40947408 SUPPORT Other
"Arthrogryposis multiplex congenita (AMC) is a clinical syndrome with complex etiology."
The consensus directly supports phenotype-first, etiology-second modeling.
PMID:38856159 SUPPORT Human Clinical
"Thus, akin to CPSFS, both dominant and recessively inherited distal arthrogryposis can be caused by variants in MYH3."
Even within one gene-associated distal group, different inheritance modes occur, illustrating why inheritance cannot be assigned to AMC generally.
Does fetal akinesia constitute a universal mechanism for every AMC case?
INTERPRETATION RESOLVED interpretation_fetal_akinesia_is_a_bounded_route
Attached to
pathophysiology#Etiology-specific fetal hypomobility or akinesia pathophysiology#Movement-dependent joint development disruption
Rat and chick immobilization experiments demonstrate that reduced movement can be sufficient to disrupt joint development and produce contractures. They do not establish that every clinically defined AMC case traverses this route, and clinical sources emphasize etiologic heterogeneity. The graph therefore marks this branch provisional and explicitly scoped.
Show evidence (2 references)
PMID:33771841 SUPPORT Model Organism
"We demonstrate partial recovery of movement and partial recovery of joint development under both recovery conditions"
Controlled restoration of movement supports causality within the experimental model.
PMID:40947408 SUPPORT Other
"Arthrogryposis multiplex congenita (AMC) is a clinical syndrome with complex etiology."
Clinical heterogeneity prevents extrapolation of one model pathway to all AMC etiologies.
Which causes account for AMC cases that remain unresolved after current cytogenomic and sequencing evaluation, and how should testing be prioritized across prenatal phenotype groups?
KNOWLEDGE GAP OPEN gap_unsolved_etiology_after_current_testing
Attached to
diagnosis#Etiology-directed cytogenomic and sequencing tests
Recent fetal cohorts report improved but incomplete and setting-specific diagnostic yields. Their ascertainment, phenotype mix, and testing sequence differ, so the percentages should not be converted into a universal expected yield or a fixed algorithm.
Show evidence (2 references)
PMID:40195522 SUPPORT Human Clinical
"The overall genetic diagnostic yield was 28% (18/64)"
Most cases in this consecutive fetal cohort remained without a genetic diagnosis despite perinatal testing.
PMID:41936055 SUPPORT Human Clinical
"By exome sequencing, we identified causative variants in 14 of 42 families with negative karyotype and CNV results"
Sequential exome testing resolved a subset while leaving a substantial unsolved group.
⚙

Pathophysiology

4
Etiology-specific fetal hypomobility or akinesia
Reduced or absent fetal movement is a mechanistically supported route to contractures when an upstream neurologic, neuromuscular, muscular, mechanical, or environmental process restricts movement. Evidence for sufficiency comes mainly from experimental immobilization. This node represents a bounded causal branch and is not asserted for every person meeting the AMC definition.
Downstream
Decreased fetal movement In this etiologic branch, the upstream process manifests as reduced or absent fetal movement; this phenotype is not required in all AMC cases.
Movement-dependent joint development disruption Experimental loss of embryonic movement perturbs separation and organization of developing joints.
Show evidence (2 references)
PMID:6685864 SUPPORT Model Organism
"It is suggested that this phenotype is not specific but, rather, represents a deformation sequence which results from fetal immobilization or akinesia."
Pharmacologic fetal paralysis in rats supports immobilization as a sufficient route to a contracture-containing deformation sequence.
PMID:33771841 SUPPORT Model Organism
"reduced or absent movement can lead to long-term skeletal defects, such as Fetal Akinesia Deformation Sequence, joint dysplasia and arthrogryposis."
The chick immobilization study supports a movement-dependent developmental route while remaining model-organism evidence.
Movement-dependent joint development disruption
In immobilized chick embryos, developing joints show reduced interzones, fusion across cartilaginous rudiments, and impaired cavitation. Partial recovery after movement resumes indicates that timing and joint site matter. Translation of these experimental findings to individual human AMC etiologies remains incomplete.
Downstream
Congenital multi-region contracture state Sustained immobility can culminate in congenital contractures through abnormal joint formation and periarticular adaptation.
Show evidence (1 reference)
PMID:33771841 SUPPORT Model Organism
"We demonstrate partial recovery of movement and partial recovery of joint development under both recovery conditions, but no improvement in spine defects."
The controlled recovery experiment supports movement-sensitive joint development and anatomical variation in reversibility.
Amyoplasia-pattern fatty-fibrous muscle replacement
In the Amyoplasia pattern, affected limb muscles may be replaced by fatty-fibrous tissue and occur with characteristic limb positions. This human tissue observation applies to Amyoplasia and must not be generalized to every etiologic form of AMC; the causal ordering remains incompletely resolved.
Downstream
Congenital multi-region contracture state Amyoplasia-associated muscle replacement and the contracture pattern co-occur, but the cited clinical series does not establish a complete molecular causal chain.
Show evidence (1 reference)
PMID:24459070 SUPPORT Human Clinical
"Affected limbs had characteristic positions with fatty-fibrous replacement of muscle."
The large clinical series documents this Amyoplasia-specific tissue finding and limb pattern.
Congenital multi-region contracture state
Fixed congenital contractures in at least two different body regions are the shared clinical endpoint of heterogeneous upstream pathways. This node is the phenotype-level convergence point, not evidence for one shared gene, inheritance mode, or universal molecular mechanism.
Downstream
Arthrogryposis multiplex congenita phenotype Multi-region congenital contractures satisfy the phenotype definition of AMC.
Limb joint contracture Limb joints are commonly among the affected body regions, although the joints and positions vary by etiologic pattern.
Talipes equinovarus Clubfoot is a frequent but non-obligate limb-position phenotype whose occurrence and treatment response vary across AMC patterns.
Limitation of joint mobility Fixed contractures reduce available range of motion, with functional impact determined by distribution and severity.
Show evidence (1 reference)
PMID:38856159 SUPPORT Human Clinical
"Arthrogryposis is a clinical feature defined by congenital joint contractures in two or more different body areas"
The source supports the multi-region contracture endpoint used to define the umbrella.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Arthrogryposis Multiplex Congenita Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

5
Limbs 1
Talipes equinovarus HP:0001762 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Talipes equinovarus (HP:0001762). HP:0001762 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:41936055 SUPPORT Human Clinical
"The most common prenatal ultrasound finding was clubfoot, observed in 50.7% (35/69) of fetuses."
This cohort-specific estimate supports common prenatal clubfoot without making it universal.
Musculoskeletal 1
Limitation of joint mobility HP:0001376 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Limitation of joint mobility (HP:0001376). HP:0001376 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:33104047 SUPPORT Human Clinical
"Contractures can lead to decreased range of motion and strength, and affect ambulation and autonomy."
The pediatric cohort directly supports limited motion and its functional consequences.
Other 3
Arthrogryposis multiplex congenita phenotype HP:0002804 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Arthrogryposis multiplex congenita (HP:0002804). HP:0002804 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38856159 SUPPORT Human Clinical
"Arthrogryposis is a clinical feature defined by congenital joint contractures in two or more different body areas"
The source states the defining multi-region congenital contracture phenotype.
Limb joint contracture HP:0003121 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Limb joint contracture (HP:0003121). HP:0003121 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:24459070 SUPPORT Human Clinical
"Upper limb involvement was usually characterized by extended elbows. Lower limbs were held in various positions at birth"
The Amyoplasia series demonstrates pattern-specific upper- and lower-limb contracture positioning.
Decreased fetal movement HP:0001558 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Decreased fetal movement (HP:0001558). HP:0001558 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:41936055 SUPPORT Human Clinical
"A comprehensive joint and movement assessment is essential when clubfoot is detected."
The fetal cohort supports movement assessment as part of prenatal AMC evaluation but does not establish reduced movement in every fetus.
PMID:6685864 SUPPORT Model Organism
"represents a deformation sequence which results from fetal immobilization or akinesia"
Experimental evidence supports the causal relevance of this phenotype in the bounded fetal-akinesia branch.
💊

Medical Actions

5
Individualized rehabilitation and physical therapy
Category: Therapeutic Action: physical therapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is physical therapy (NCIT:C15302). NCIT:C15302 is a clinical intervention from the NCI Thesaurus. Ontology label: Physical Therapy NCIT:C15302
Goal-directed rehabilitation is tailored to involved joints, muscle strength, mobility, transfers, self-care, communication, and the underlying diagnosis. The evidence supports rehabilitation as a management domain, not one universally effective intensity or protocol.
Target Phenotypes: Limb joint contracture HP:0003121 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Limb joint contracture (HP:0003121). HP:0003121 is a phenotype from the Human Phenotype Ontology. Limitation of joint mobility HP:0001376 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Limitation of joint mobility (HP:0001376). HP:0001376 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40947408 SUPPORT Other
"The goal of treatment is to improve the self-care ability of children, and the methods mainly include rehabilitation therapy"
The consensus supports rehabilitation with a functional, self-care goal.
Splinting and orthotic support
Category: Therapeutic
Splints and orthoses can support positioning and function as part of an individualized plan. Device choice, duration, and goals depend on the joint, growth, skin tolerance, and etiologic pattern.
Target Phenotypes: Limb joint contracture HP:0003121 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Limb joint contracture (HP:0003121). HP:0003121 is a phenotype from the Human Phenotype Ontology. Limitation of joint mobility HP:0001376 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Limitation of joint mobility (HP:0001376). HP:0001376 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40947408 SUPPORT Other
"splint support and orthotic fixation"
The expert consensus explicitly includes splint and orthotic management.
Ponseti-style manipulation and serial casting for arthrogrypotic clubfoot
Category: Therapeutic
Ponseti-style manipulation and serial casting can be used as an initial clubfoot strategy. Small AMC cohorts show frequent initial correction but substantial relapse and later surgery, with poorer results in Amyoplasia than distal arthrogryposis. These data do not support a uniform outcome claim across all AMC.
Target Phenotypes: Talipes equinovarus HP:0001762 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Talipes equinovarus (HP:0001762). HP:0001762 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:37215511 SUPPORT Human Clinical
"an initial correction was achieved in 13 out of 19 arthrogrypotic clubfeet (68.4%)."
The small prospective cohort supports initial correction in a subset and provides a denominator that prevents overgeneralization.
PMID:39342344 SUPPORT Human Clinical
"Most of the studies reviewed (11 case series, 144 patients) reported high initial clinical correction rates, followed by high recurrence rates and the need for further surgeries."
Midterm cohort data and the accompanying literature review support both initial benefit and the important relapse/surgery boundary.
Selected orthopedic surgery
Category: Therapeutic Action: surgical procedureNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is surgical procedure (NCIT:C15329). NCIT:C15329 is a clinical intervention from the NCI Thesaurus. Ontology label: Surgical Procedure NCIT:C15329
Joint- and pattern-specific orthopedic surgery may be considered when contractures or deformities substantially limit function and conservative measures are insufficient. Procedure choice and timing cannot be generalized across the AMC umbrella.
Target Phenotypes: Limb joint contracture HP:0003121 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Limb joint contracture (HP:0003121). HP:0003121 is a phenotype from the Human Phenotype Ontology. Talipes equinovarus HP:0001762 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Talipes equinovarus (HP:0001762). HP:0001762 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40947408 SUPPORT Other
"as well as orthopedic surgery."
The consensus includes orthopedic surgery among management options without specifying one universal procedure.
Etiology-specific genetic counseling
Category: Counseling / Informational Action: genetic counselingNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is genetic counseling (NCIT:C15240). NCIT:C15240 is a clinical intervention from the NCI Thesaurus. Ontology label: Genetic Counseling NCIT:C15240
Counseling should explain that AMC is a phenotype, review the identified or suspected underlying cause, and derive recurrence risk and reproductive options from that diagnosis. No single recurrence risk applies to AMC.
Show evidence (2 references)
PMID:6685864 SUPPORT Model Organism
"identification of the underlying pathologic process (etiology of the akinesia) to allow for proper classification and genetic counseling"
The source directly links etiologic classification, rather than the umbrella phenotype alone, to appropriate counseling.
PMID:41936055 SUPPORT Human Clinical
"ES significantly improves the diagnostic yield by providing key information for genetic counseling."
The fetal cohort supports molecular etiologic information as an input to counseling.
🔬

Diagnosis

4
Clinical recognition and distribution mapping
Confirm congenital contractures in at least two body regions, document every involved joint and position, and assess craniofacial, neurologic, neuromuscular, skeletal, and other systemic findings. The clinical AMC label should be followed by etiologic classification when possible.
clinical assessment NCIT:C124351 NCI Thesaurus (NCIT)
Results: Multi-region congenital contractures establish the AMC phenotype; associated findings guide the underlying-diagnosis work-up.
Show evidence (1 reference)
PMID:38856159 SUPPORT Human Clinical
"Arthrogryposis is a clinical feature defined by congenital joint contractures in two or more different body areas"
The source supports the clinical threshold used to recognize the phenotype.
Prenatal joint, movement, and multisystem ultrasonography
Prenatal ultrasound evaluates joint posture, limb movement, clubfoot, and associated craniofacial or multisystem anomalies. Serial scans may be needed because recognition can occur at different gestational stages.
fetal ultrasonography NCIT:C222238 NCI Thesaurus (NCIT)
Results: Multiple contractures or abnormal posture with reduced movement and associated anomalies supports prenatal AMC and guides testing and counseling.
Show evidence (1 reference)
PMID:41936055 SUPPORT Human Clinical
"A comprehensive joint and movement assessment is essential when clubfoot is detected."
The 69-fetus cohort supports systematic prenatal joint and movement assessment.
Etiology-directed cytogenomic and sequencing tests
Select testing from karyotype, chromosomal microarray or other copy-number analysis, multigene sequencing, exome sequencing, or genome sequencing based on prenatal and postnatal findings. A negative result does not negate the clinical AMC phenotype, and cohort-specific yields must not be treated as a universal diagnostic rate.
genetic testing NCIT:C15709 NCI Thesaurus (NCIT)
Results: A pathogenic chromosomal or sequence finding can identify the underlying diagnosis and its inheritance; unresolved testing leaves AMC as a descriptive phenotype.
Show evidence (2 references)
PMID:41936055 SUPPORT Human Clinical
"Aneuploidy and pathogenic copy number variations (CNV) were identified in 10.45% (7/67) of the unrelated families."
The fetal cohort demonstrates that chromosomal and copy-number testing can resolve a subset of cases.
PMID:40195522 SUPPORT Human Clinical
"Whole exome sequencing had the highest yield (41.7%)."
The consecutive fetal cohort supports exome sequencing as a high-yield component in that referral setting while not establishing a universal rate.
Postnatal etiologic neurologic and systemic evaluation
History, pedigree, detailed physical and neurologic examination, imaging, neuromuscular electrophysiology, and targeted laboratory tests are selected according to the phenotype. The purpose is to locate the upstream disorder, not merely to reconfirm contractures.
clinical assessment NCIT:C124351 NCI Thesaurus (NCIT)
Results: Central, peripheral nerve, neuromuscular-junction, muscle, connective-tissue, skeletal, multisystem, or environmental findings narrow the etiologic class.
Show evidence (1 reference)
PMID:40947408 SUPPORT Other
"clinical evaluation, genetic examination, neuromuscular electrophysiological examination, imaging examination and special laboratory examination after birth"
The multidisciplinary consensus supports a phenotype-directed postnatal etiologic work-up across modalities.
📈

Progression

2
Prenatal emergence and detection
Age: Fetal period
Contractures and reduced movement may become apparent at different gestational stages. A normal earlier scan does not exclude later recognition, and serial assessment may be appropriate when findings evolve.
Show evidence (1 reference)
PMID:41936055 SUPPORT Human Clinical
"AMC can occur at any stage of pregnancy and exhibits phenotypic heterogeneity. Regular follow-up ultrasounds are essential."
The retrospective fetal cohort supports variable prenatal timing and serial ultrasound follow-up.
Congenital contracture state with variable later function
Age: Birth onward
The defining contractures are congenital and described as non-progressive. This does not mean that range of motion, secondary deformity, mobility, or care needs remain static; those outcomes vary with growth, distribution, treatment, and the underlying diagnosis.
Show evidence (1 reference)
PMID:40947408 SUPPORT Other
"It is a non-progressive syndrome characterized by joint deformity and stiffness, muscle atrophy, reduction of skin folds and subcutaneous tissue, and contracture of periarticular tissue"
The consensus supports congenital non-progression of the defining syndrome while the entry separately preserves variable functional course.
⚖️

Clinical Burden

Variable
Functional burden ranges from independent ambulation and self-care to major mobility limitation and repeated orthopedic care. Contracture count, distribution, knee involvement, central nervous system or syndromic involvement, and the underlying etiology materially change outcome, so no single low, moderate, or high burden level represents the umbrella.
Show evidence (2 references)
PMID:41475428 SUPPORT Human Clinical
"Greater joint involvement, particularly at the knees, was a strong negative factor."
The multicenter cohort links distribution and number of contractures with mobility, supporting substantial within-syndrome variability.
PMID:33104047 SUPPORT Human Clinical
"Contractures can lead to decreased range of motion and strength, and affect ambulation and autonomy."
The pediatric cohort directly documents the functional domains affected by AMC contractures.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Arthrogryposis Multiplex Congenita:

Amyoplasia
Overlapping Features Amyoplasia is a specific clinical pattern within the AMC umbrella rather than a synonym for every AMC presentation. Characteristic limb positions, fatty-fibrous muscle replacement, and apparently sporadic occurrence favor this classification.
Distinguishing Features
  • Characteristic limb-position pattern with fatty-fibrous replacement of affected muscle.
  • The large clinical series describes Amyoplasia itself as sporadic.
Show evidence (1 reference)
PMID:24459070 SUPPORT Human Clinical
"Amyoplasia appears to be completely sporadic."
This pattern-specific observation helps separate Amyoplasia from familial Mendelian causes without assigning sporadic inheritance to AMC as a whole.
Distal arthrogryposis group
Overlapping Features Distal arthrogryposis diagnoses emphasize hand and foot contractures with comparatively less proximal involvement. Individual disorders in this group can have defined genes and inheritance modes, which should be recorded only after the specific diagnosis is established.
Distinguishing Features
  • Distal joints predominate and proximal joint involvement is less extensive than in Amyoplasia in a pediatric cohort.
  • A compatible family history or molecular result supports a specific distal arthrogryposis diagnosis, not generic AMC.
Show evidence (1 reference)
PMID:33104047 SUPPORT Human Clinical
"Children with DA had less involvement of the proximal joints than those in the two other groups."
The cohort provides a clinically useful distribution boundary for this etiologic group.
Fetal akinesia deformation sequence
Overlapping Features Fetal akinesia deformation sequence is a severe overlapping deformation pattern caused by marked prenatal immobilization. Multiple contractures may coexist with pulmonary hypoplasia, micrognathia, growth restriction, short umbilical cord, and polyhydramnios. It is not synonymous with all AMC, and the cause of the akinesia still requires investigation.
Distinguishing Features
  • Pulmonary hypoplasia and craniofacial or broader deformation findings suggest a severe fetal-akinesia sequence.
  • Identifying the neurologic, neuromuscular, environmental, or mechanical cause of akinesia is necessary for classification and counseling.
Show evidence (1 reference)
PMID:6685864 SUPPORT Model Organism
"Diagnostic evaluation of patients with this group of anomalies should include the identification of the underlying pathologic process (etiology of the akinesia)"
The experimental paper explicitly frames the sequence as nonspecific and calls for identification of its upstream cause.
📊

Related Datasets

1
Loss of protein function of ZC4H2 gene causing severe phenotypes of female-restricted Wieacker Wolff Syndrome geo:GSE208171
Background: Pathogenic variants of zinc finger C4H2-type containing (ZC4H2) on the X chromosome caused a group of genetic diseases called ZC4H2-associated rare disorders (ZARD), including Wieacker-Wolff Syndrome (WRWF) and Female-restricted Wieacker-Wolff Syndrome (WRWFFR). Patients displayed arthrogryposis multiplex congenita (AMC), central and peripheral nervous system involvement, as well as multiple dysmorphic features. The underlying mechanisms of the complex syndrome remain to be elucidated. Methods: Expression levels of ZC4H2 were knockdown in neural stem cells (NSCs) derived from induced pluripotent stem cells (iPSCs) by lentiviral-expressed shRNAs against ZC4H2.
human BULK RNA SEQ n=6
Identified by GEO DataSets index search for Arthrogryposis Multiplex Congenita (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-07-31. Title, sample count, and organism are GEO's own values.
🐁

Animal Models

2
Pharmacologic fetal paralysis by transuterine curare exposure Rat (Rattus norvegicus)
Daily fetal curare exposure from gestational day 18 to term produced multiple joint contractures and a broader deformation sequence not seen in sham-operated or untouched littermates. This demonstrates sufficiency of late-gestation immobilization in a rat model, not universality in human AMC.
Species
Rat (Rattus norvegicus)
Genotype
Pharmacologic fetal paralysis by transuterine curare exposure
Show evidence (1 reference)
PMID:6685864 SUPPORT Model Organism
"Neither sham-operated nor untouched littermate control fetuses had any of these anomalies."
The controlled comparison supports a causal effect of experimental fetal paralysis on the deformation sequence.
Experimental embryonic immobilization followed by natural or stimulated movement recovery Chicken (Gallus gallus)
Embryos immobilized during joint development showed interzone and skeletal-rudiment defects. Resumption of movement partially restored development in some joints, with site-specific differences. The model informs timing and reversibility but does not directly test heterogeneous human AMC etiologies.
Species
Chicken (Gallus gallus)
Genotype
Experimental embryonic immobilization followed by natural or stimulated movement recovery
Show evidence (1 reference)
PMID:33771841 SUPPORT Model Organism
"The hip joint showed the best recovery with improved rudiment separation, tissue organisation and commencement of cavitation."
The recovery experiment directly demonstrates movement-sensitive joint development in the chick model.
{ }

Source YAML

click to show 
name: Arthrogryposis Multiplex Congenita
creation_date: "2026-05-13T12:00:00Z"
category: Complex
description: >-
  Arthrogryposis multiplex congenita (AMC) is a descriptive congenital
  phenotype and clinical syndrome, not a single etiologic disease. It is
  defined by congenital contractures affecting at least two different body
  regions. The distribution, associated anomalies, functional consequences,
  underlying cause, and recurrence risk vary widely. Etiologies can involve
  the central or peripheral nervous system, neuromuscular junction, muscle,
  connective or skeletal tissue, or the intrauterine environment. Reduced
  fetal movement is a well-supported route to contracture formation in some
  etiologic branches, but it is not modeled here as a proven universal cause.
synonyms:
- AMC
- Arthrogryposis
- Multiple congenital contractures
disease_term:
  preferred_term: arthrogryposis multiplex congenita
  term:
    id: MONDO:0015168
    label: arthrogryposis multiplex congenita
parents:
- Congenital Disorder

definitions:
- name: Multi-region congenital contracture definition
  definition_type: OTHER
  description: >-
    AMC is identified clinically when congenital joint contractures involve
    two or more different body regions. This definition identifies a phenotype
    for etiologic investigation; it does not assign a gene, inheritance mode,
    or mechanism.
  evidence:
  - reference: PMID:38856159
    reference_title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Arthrogryposis is a clinical feature defined by congenital joint
      contractures in two or more different body areas
    explanation: >-
      The clinical genetics report states the phenotype-level inclusion
      definition without treating arthrogryposis as one molecular disorder.
- name: Etiologically heterogeneous clinical-syndrome definition
  definition_type: OTHER
  description: >-
    AMC is an etiologically heterogeneous clinical syndrome. A complete
    diagnosis therefore includes both recognition of the contracture phenotype
    and an attempt to determine the underlying disorder or exposure.
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Arthrogryposis multiplex congenita (AMC) is a clinical syndrome with complex etiology."
    explanation: >-
      The multidisciplinary consensus explicitly distinguishes the clinical
      syndrome from its many possible etiologies.
  - reference: PMID:40195522
    reference_title: "Perinatal genetic diagnostic yield in a population of fetuses with the phenotype arthrogryposis multiplex congenita: a cohort study 2007-2021."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Arthrogryposis multiplex congenita (AMC) presents challenges for prenatal
      detection due to its heterogeneous etiology, onset, and phenotypical
      manifestations.
    explanation: >-
      The consecutive fetal cohort independently supports heterogeneity of
      cause, onset, and presentation.

has_subtypes:
- name: Amyoplasia pattern
  display_name: Amyoplasia
  description: >-
    Amyoplasia is a recognized clinical pattern within AMC, with characteristic
    limb positions and fatty-fibrous replacement of affected muscle. Its
    sporadic occurrence is a property of Amyoplasia, not an inheritance rule
    for the AMC umbrella.
  subtype_term:
    preferred_term: congenital amyoplasia
    term:
      id: MONDO:0044629
      label: congenital amyoplasia
  evidence:
  - reference: PMID:24459070
    reference_title: Amyoplasia revisited.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected limbs had characteristic positions with fatty-fibrous replacement of muscle."
    explanation: >-
      The 560-person Amyoplasia series supports this pattern-specific tissue
      and limb-position phenotype.
- name: Distal arthrogryposis pattern
  display_name: Distal arthrogryposis
  description: >-
    Distal arthrogryposis is a group of etiologic diagnoses in which distal
    joints are emphasized and proximal involvement is generally less extensive.
    Molecular and inheritance findings for individual distal arthrogryposis
    disorders must not be generalized to all AMC.
  subtype_term:
    preferred_term: distal arthrogryposis
    term:
      id: MONDO:0019942
      label: distal arthrogryposis
  evidence:
  - reference: PMID:33104047
    reference_title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Children with DA had less involvement of the proximal joints than those in the two other groups."
    explanation: >-
      The pediatric cohort supports distal arthrogryposis as a clinically
      distinguishable distribution pattern.
- name: Central nervous system, neuromuscular, and syndromic patterns
  description: >-
    AMC may accompany central nervous system, peripheral neuromuscular, or
    multisystem disorders. This is an etiologic-work-up grouping rather than a
    single formal subtype, and associated prognosis is determined by the
    underlying diagnosis.
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      AMC may be divided into amyoplasia, distal arthrogryposis, central nervous
      system and neuromuscular diseases
    explanation: >-
      The consensus uses these groups to organize diagnostic evaluation while
      retaining AMC as a complex clinical syndrome.

clinical_burden:
  burden_level: VARIABLE
  rationale: >-
    Functional burden ranges from independent ambulation and self-care to major
    mobility limitation and repeated orthopedic care. Contracture count,
    distribution, knee involvement, central nervous system or syndromic
    involvement, and the underlying etiology materially change outcome, so no
    single low, moderate, or high burden level represents the umbrella.
  evidence:
  - reference: PMID:41475428
    reference_title: "Factors Associated With Functional Mobility in 256 Children With Arthrogryposis Multiplex Congenita: A Multicentric Cross-Sectional Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Greater joint involvement, particularly at the knees, was a strong negative factor."
    explanation: >-
      The multicenter cohort links distribution and number of contractures with
      mobility, supporting substantial within-syndrome variability.
  - reference: PMID:33104047
    reference_title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Contractures can lead to decreased range of motion and strength, and
      affect ambulation and autonomy.
    explanation: >-
      The pediatric cohort directly documents the functional domains affected
      by AMC contractures.
progression:
- phase: Prenatal emergence and detection
  age_range: Fetal period
  notes: >-
    Contractures and reduced movement may become apparent at different
    gestational stages. A normal earlier scan does not exclude later recognition,
    and serial assessment may be appropriate when findings evolve.
  evidence:
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "AMC can occur at any stage of pregnancy and exhibits phenotypic heterogeneity. Regular follow-up ultrasounds are essential."
    explanation: >-
      The retrospective fetal cohort supports variable prenatal timing and
      serial ultrasound follow-up.
- phase: Congenital contracture state with variable later function
  age_range: Birth onward
  notes: >-
    The defining contractures are congenital and described as non-progressive.
    This does not mean that range of motion, secondary deformity, mobility, or
    care needs remain static; those outcomes vary with growth, distribution,
    treatment, and the underlying diagnosis.
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      It is a non-progressive syndrome characterized by joint deformity and
      stiffness, muscle atrophy, reduction of skin folds and subcutaneous
      tissue, and contracture of periarticular tissue
    explanation: >-
      The consensus supports congenital non-progression of the defining
      syndrome while the entry separately preserves variable functional course.

pathophysiology:
- name: Etiology-specific fetal hypomobility or akinesia
  description: >-
    Reduced or absent fetal movement is a mechanistically supported route to
    contractures when an upstream neurologic, neuromuscular, muscular, mechanical,
    or environmental process restricts movement. Evidence for sufficiency comes
    mainly from experimental immobilization. This node represents a bounded
    causal branch and is not asserted for every person meeting the AMC definition.
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:6685864
    reference_title: "Fetal akinesia deformation sequence: an animal model."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      It is suggested that this phenotype is not specific but, rather,
      represents a deformation sequence which results from fetal immobilization
      or akinesia.
    explanation: >-
      Pharmacologic fetal paralysis in rats supports immobilization as a
      sufficient route to a contracture-containing deformation sequence.
  - reference: PMID:33771841
    reference_title: Joint development recovery on resumption of embryonic movement following paralysis.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      reduced or absent movement can lead to long-term skeletal defects, such as
      Fetal Akinesia Deformation Sequence, joint dysplasia and arthrogryposis.
    explanation: >-
      The chick immobilization study supports a movement-dependent developmental
      route while remaining model-organism evidence.
  downstream:
  - target: Decreased fetal movement
    causal_link_type: DIRECT
    description: >-
      In this etiologic branch, the upstream process manifests as reduced or
      absent fetal movement; this phenotype is not required in all AMC cases.
    evidence:
    - reference: PMID:6685864
      reference_title: "Fetal akinesia deformation sequence: an animal model."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Rat fetuses were paralyzed by daily transuterine injections of curare
        from day 18 of gestation until term (day 21).
      explanation: >-
        The experimental perturbation directly produced fetal immobilization in
        the model.
  - target: Movement-dependent joint development disruption
    causal_link_type: DIRECT
    description: >-
      Experimental loss of embryonic movement perturbs separation and
      organization of developing joints.
    evidence:
    - reference: PMID:33771841
      reference_title: Joint development recovery on resumption of embryonic movement following paralysis.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        At developing joints, defects include reduced joint interzones with
        frequent fusion of cartilaginous skeletal rudiments across the joint.
      explanation: >-
        The chick model directly links immobilization with impaired joint
        interzone development and rudiment separation.
- name: Movement-dependent joint development disruption
  description: >-
    In immobilized chick embryos, developing joints show reduced interzones,
    fusion across cartilaginous rudiments, and impaired cavitation. Partial
    recovery after movement resumes indicates that timing and joint site matter.
    Translation of these experimental findings to individual human AMC etiologies
    remains incomplete.
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:33771841
    reference_title: Joint development recovery on resumption of embryonic movement following paralysis.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      We demonstrate partial recovery of movement and partial recovery of joint
      development under both recovery conditions, but no improvement in spine
      defects.
    explanation: >-
      The controlled recovery experiment supports movement-sensitive joint
      development and anatomical variation in reversibility.
  downstream:
  - target: Congenital multi-region contracture state
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Reduced joint interzone separation and cavitation
    description: >-
      Sustained immobility can culminate in congenital contractures through
      abnormal joint formation and periarticular adaptation.
    evidence:
    - reference: PMID:6685864
      reference_title: "Fetal akinesia deformation sequence: an animal model."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        The following anomalies were noted at the time of delivery: multiple
        joint contractures, pulmonary hypoplasia, micrognathia, fetal growth
        retardation, short umbilical cords, and polyhydramnios.
      explanation: >-
        The rat experiment demonstrates multiple congenital contractures after
        sustained fetal paralysis.
- name: Amyoplasia-pattern fatty-fibrous muscle replacement
  description: >-
    In the Amyoplasia pattern, affected limb muscles may be replaced by
    fatty-fibrous tissue and occur with characteristic limb positions. This
    human tissue observation applies to Amyoplasia and must not be generalized
    to every etiologic form of AMC; the causal ordering remains incompletely
    resolved.
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:24459070
    reference_title: Amyoplasia revisited.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected limbs had characteristic positions with fatty-fibrous replacement of muscle."
    explanation: >-
      The large clinical series documents this Amyoplasia-specific tissue
      finding and limb pattern.
  downstream:
  - target: Congenital multi-region contracture state
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Amyoplasia-associated muscle replacement and the contracture pattern
      co-occur, but the cited clinical series does not establish a complete
      molecular causal chain.
    evidence:
    - reference: PMID:24459070
      reference_title: Amyoplasia revisited.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Affected limbs had characteristic positions with fatty-fibrous replacement of muscle."
      explanation: >-
        The association is directly observed, while the intermediate causal
        steps are not resolved by this clinical series.
- name: Congenital multi-region contracture state
  description: >-
    Fixed congenital contractures in at least two different body regions are
    the shared clinical endpoint of heterogeneous upstream pathways. This node
    is the phenotype-level convergence point, not evidence for one shared gene,
    inheritance mode, or universal molecular mechanism.
  evidence:
  - reference: PMID:38856159
    reference_title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Arthrogryposis is a clinical feature defined by congenital joint
      contractures in two or more different body areas
    explanation: >-
      The source supports the multi-region contracture endpoint used to define
      the umbrella.
  downstream:
  - target: Arthrogryposis multiplex congenita phenotype
    causal_link_type: DIRECT
    description: >-
      Multi-region congenital contractures satisfy the phenotype definition of
      AMC.
    evidence:
    - reference: PMID:38856159
      reference_title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Arthrogryposis is a clinical feature defined by congenital joint
        contractures in two or more different body areas
      explanation: >-
        The defining phenotype directly connects the convergence node to the
        HPO AMC phenotype.
  - target: Limb joint contracture
    causal_link_type: DIRECT
    description: >-
      Limb joints are commonly among the affected body regions, although the
      joints and positions vary by etiologic pattern.
    evidence:
    - reference: PMID:33104047
      reference_title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Contractures and deformities of the foot and ankle were the most
        prevalent
      explanation: >-
        The pediatric cohort supports limb-joint involvement across major AMC
        clinical groups.
  - target: Talipes equinovarus
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Clubfoot is a frequent but non-obligate limb-position phenotype whose
      occurrence and treatment response vary across AMC patterns.
    evidence:
    - reference: PMID:41936055
      reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The most common prenatal ultrasound finding was clubfoot, observed in 50.7% (35/69) of fetuses."
      explanation: >-
        The fetal cohort establishes clubfoot as a common, not universal,
        manifestation in that ascertainment setting.
  - target: Limitation of joint mobility
    causal_link_type: DIRECT
    description: >-
      Fixed contractures reduce available range of motion, with functional
      impact determined by distribution and severity.
    evidence:
    - reference: PMID:33104047
      reference_title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Contractures can lead to decreased range of motion and strength, and affect ambulation and autonomy."
      explanation: >-
        The cohort directly links contractures with reduced range of motion and
        functional consequences.

phenotypes:
- name: Arthrogryposis multiplex congenita phenotype
  category: Musculoskeletal
  description: >-
    Congenital contractures affecting at least two different body regions are
    the defining phenotype. This phenotype alone does not determine etiology or
    recurrence risk.
  phenotype_term:
    preferred_term: Arthrogryposis multiplex congenita
    term:
      id: HP:0002804
      label: Arthrogryposis multiplex congenita
  evidence:
  - reference: PMID:38856159
    reference_title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Arthrogryposis is a clinical feature defined by congenital joint
      contractures in two or more different body areas
    explanation: >-
      The source states the defining multi-region congenital contracture
      phenotype.
- name: Limb joint contracture
  category: Musculoskeletal
  description: >-
    Limb joints are commonly involved, but proximal-versus-distal distribution,
    symmetry, position, and severity differ among Amyoplasia, distal
    arthrogryposis, and syndromic or neuromuscular patterns.
  phenotype_term:
    preferred_term: Limb joint contracture
    term:
      id: HP:0003121
      label: Limb joint contracture
  evidence:
  - reference: PMID:24459070
    reference_title: Amyoplasia revisited.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Upper limb involvement was usually characterized by extended elbows.
      Lower limbs were held in various positions at birth
    explanation: >-
      The Amyoplasia series demonstrates pattern-specific upper- and lower-limb
      contracture positioning.
- name: Talipes equinovarus
  category: Musculoskeletal
  description: >-
    Clubfoot is common in AMC cohorts and particularly characteristic in
    lower-limb Amyoplasia, but it is not required for the AMC definition.
  phenotype_term:
    preferred_term: Talipes equinovarus
    term:
      id: HP:0001762
      label: Talipes equinovarus
  evidence:
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most common prenatal ultrasound finding was clubfoot, observed in 50.7% (35/69) of fetuses."
    explanation: >-
      This cohort-specific estimate supports common prenatal clubfoot without
      making it universal.
- name: Decreased fetal movement
  category: Prenatal
  description: >-
    Reduced fetal movement may be detected in the fetal-akinesia branch and is
    an important etiologic clue. It is intentionally not marked as obligatory
    or universal for the entire AMC umbrella.
  phenotype_term:
    preferred_term: Decreased fetal movement
    term:
      id: HP:0001558
      label: Decreased fetal movement
  evidence:
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A comprehensive joint and movement assessment is essential when clubfoot is detected."
    explanation: >-
      The fetal cohort supports movement assessment as part of prenatal AMC
      evaluation but does not establish reduced movement in every fetus.
  - reference: PMID:6685864
    reference_title: "Fetal akinesia deformation sequence: an animal model."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      represents a deformation sequence which results from fetal immobilization
      or akinesia
    explanation: >-
      Experimental evidence supports the causal relevance of this phenotype in
      the bounded fetal-akinesia branch.
- name: Limitation of joint mobility
  category: Musculoskeletal
  description: >-
    Contractures reduce joint range of motion and can affect ambulation,
    transfers, self-care, and autonomy; functional impact varies markedly.
  phenotype_term:
    preferred_term: Limitation of joint mobility
    term:
      id: HP:0001376
      label: Limitation of joint mobility
  evidence:
  - reference: PMID:33104047
    reference_title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Contractures can lead to decreased range of motion and strength, and affect ambulation and autonomy."
    explanation: >-
      The pediatric cohort directly supports limited motion and its functional
      consequences.

animal_models:
- species: Rat (Rattus norvegicus)
  genotype: Pharmacologic fetal paralysis by transuterine curare exposure
  description: >-
    Daily fetal curare exposure from gestational day 18 to term produced
    multiple joint contractures and a broader deformation sequence not seen in
    sham-operated or untouched littermates. This demonstrates sufficiency of
    late-gestation immobilization in a rat model, not universality in human AMC.
  evidence:
  - reference: PMID:6685864
    reference_title: "Fetal akinesia deformation sequence: an animal model."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Neither sham-operated nor untouched littermate control fetuses had any of these anomalies."
    explanation: >-
      The controlled comparison supports a causal effect of experimental fetal
      paralysis on the deformation sequence.
- species: Chicken (Gallus gallus)
  genotype: Experimental embryonic immobilization followed by natural or stimulated movement recovery
  description: >-
    Embryos immobilized during joint development showed interzone and
    skeletal-rudiment defects. Resumption of movement partially restored development in
    some joints, with site-specific differences. The model informs timing and
    reversibility but does not directly test heterogeneous human AMC etiologies.
  evidence:
  - reference: PMID:33771841
    reference_title: Joint development recovery on resumption of embryonic movement following paralysis.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      The hip joint showed the best recovery with improved rudiment separation,
      tissue organisation and commencement of cavitation.
    explanation: >-
      The recovery experiment directly demonstrates movement-sensitive joint
      development in the chick model.

diagnosis:
- name: Clinical recognition and distribution mapping
  diagnosis_term:
    preferred_term: clinical assessment
    term:
      id: NCIT:C124351
      label: Clinical Evaluation
  description: >-
    Confirm congenital contractures in at least two body regions, document every
    involved joint and position, and assess craniofacial, neurologic,
    neuromuscular, skeletal, and other systemic findings. The clinical AMC label
    should be followed by etiologic classification when possible.
  results: >-
    Multi-region congenital contractures establish the AMC phenotype; associated
    findings guide the underlying-diagnosis work-up.
  evidence:
  - reference: PMID:38856159
    reference_title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Arthrogryposis is a clinical feature defined by congenital joint
      contractures in two or more different body areas
    explanation: >-
      The source supports the clinical threshold used to recognize the
      phenotype.
- name: Prenatal joint, movement, and multisystem ultrasonography
  diagnosis_term:
    preferred_term: fetal ultrasonography
    term:
      id: NCIT:C222238
      label: Fetal Ultrasound Imaging
  description: >-
    Prenatal ultrasound evaluates joint posture, limb movement, clubfoot, and
    associated craniofacial or multisystem anomalies. Serial scans may be needed
    because recognition can occur at different gestational stages.
  results: >-
    Multiple contractures or abnormal posture with reduced movement and
    associated anomalies supports prenatal AMC and guides testing and counseling.
  evidence:
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A comprehensive joint and movement assessment is essential when clubfoot is detected."
    explanation: >-
      The 69-fetus cohort supports systematic prenatal joint and movement
      assessment.
- name: Etiology-directed cytogenomic and sequencing tests
  diagnosis_term:
    preferred_term: genetic testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  description: >-
    Select testing from karyotype, chromosomal microarray or other copy-number
    analysis, multigene sequencing, exome sequencing, or genome sequencing based
    on prenatal and postnatal findings. A negative result does not negate the
    clinical AMC phenotype, and cohort-specific yields must not be treated as a
    universal diagnostic rate.
  results: >-
    A pathogenic chromosomal or sequence finding can identify the underlying
    diagnosis and its inheritance; unresolved testing leaves AMC as a descriptive
    phenotype.
  evidence:
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Aneuploidy and pathogenic copy number variations (CNV) were identified in
      10.45% (7/67) of the unrelated families.
    explanation: >-
      The fetal cohort demonstrates that chromosomal and copy-number testing can
      resolve a subset of cases.
  - reference: PMID:40195522
    reference_title: "Perinatal genetic diagnostic yield in a population of fetuses with the phenotype arthrogryposis multiplex congenita: a cohort study 2007-2021."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Whole exome sequencing had the highest yield (41.7%)."
    explanation: >-
      The consecutive fetal cohort supports exome sequencing as a high-yield
      component in that referral setting while not establishing a universal rate.
- name: Postnatal etiologic neurologic and systemic evaluation
  diagnosis_term:
    preferred_term: clinical assessment
    term:
      id: NCIT:C124351
      label: Clinical Evaluation
  description: >-
    History, pedigree, detailed physical and neurologic examination, imaging,
    neuromuscular electrophysiology, and targeted laboratory tests are selected
    according to the phenotype. The purpose is to locate the upstream disorder,
    not merely to reconfirm contractures.
  results: >-
    Central, peripheral nerve, neuromuscular-junction, muscle, connective-tissue,
    skeletal, multisystem, or environmental findings narrow the etiologic class.
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      clinical evaluation, genetic examination, neuromuscular electrophysiological
      examination, imaging examination and special laboratory examination after
      birth
    explanation: >-
      The multidisciplinary consensus supports a phenotype-directed postnatal
      etiologic work-up across modalities.

differential_diagnoses:
- name: Amyoplasia
  description: >-
    Amyoplasia is a specific clinical pattern within the AMC umbrella rather
    than a synonym for every AMC presentation. Characteristic limb positions,
    fatty-fibrous muscle replacement, and apparently sporadic occurrence favor
    this classification.
  distinguishing_features:
  - Characteristic limb-position pattern with fatty-fibrous replacement of affected muscle.
  - The large clinical series describes Amyoplasia itself as sporadic.
  evidence:
  - reference: PMID:24459070
    reference_title: Amyoplasia revisited.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Amyoplasia appears to be completely sporadic."
    explanation: >-
      This pattern-specific observation helps separate Amyoplasia from familial
      Mendelian causes without assigning sporadic inheritance to AMC as a whole.
- name: Distal arthrogryposis group
  description: >-
    Distal arthrogryposis diagnoses emphasize hand and foot contractures with
    comparatively less proximal involvement. Individual disorders in this group
    can have defined genes and inheritance modes, which should be recorded only
    after the specific diagnosis is established.
  distinguishing_features:
  - Distal joints predominate and proximal joint involvement is less extensive than in Amyoplasia in a pediatric cohort.
  - A compatible family history or molecular result supports a specific distal arthrogryposis diagnosis, not generic AMC.
  evidence:
  - reference: PMID:33104047
    reference_title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Children with DA had less involvement of the proximal joints than those in the two other groups."
    explanation: >-
      The cohort provides a clinically useful distribution boundary for this
      etiologic group.
- name: Fetal akinesia deformation sequence
  description: >-
    Fetal akinesia deformation sequence is a severe overlapping deformation
    pattern caused by marked prenatal immobilization. Multiple contractures may
    coexist with pulmonary hypoplasia, micrognathia, growth restriction, short
    umbilical cord, and polyhydramnios. It is not synonymous with all AMC, and
    the cause of the akinesia still requires investigation.
  distinguishing_features:
  - Pulmonary hypoplasia and craniofacial or broader deformation findings suggest a severe fetal-akinesia sequence.
  - Identifying the neurologic, neuromuscular, environmental, or mechanical cause of akinesia is necessary for classification and counseling.
  evidence:
  - reference: PMID:6685864
    reference_title: "Fetal akinesia deformation sequence: an animal model."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Diagnostic evaluation of patients with this group of anomalies should
      include the identification of the underlying pathologic process (etiology
      of the akinesia)
    explanation: >-
      The experimental paper explicitly frames the sequence as nonspecific and
      calls for identification of its upstream cause.

treatments:
- name: Individualized rehabilitation and physical therapy
  action_category: THERAPEUTIC
  therapeutic_modality: BEHAVIORAL
  description: >-
    Goal-directed rehabilitation is tailored to involved joints, muscle strength,
    mobility, transfers, self-care, communication, and the underlying diagnosis.
    The evidence supports rehabilitation as a management domain, not one
    universally effective intensity or protocol.
  treatment_term:
    preferred_term: physical therapy
    term:
      id: NCIT:C15302
      label: Physical Therapy
  target_phenotypes:
  - preferred_term: Limb joint contracture
    term:
      id: HP:0003121
      label: Limb joint contracture
  - preferred_term: Limitation of joint mobility
    term:
      id: HP:0001376
      label: Limitation of joint mobility
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The goal of treatment is to improve the self-care ability of children,
      and the methods mainly include rehabilitation therapy
    explanation: >-
      The consensus supports rehabilitation with a functional, self-care goal.
- name: Splinting and orthotic support
  action_category: THERAPEUTIC
  therapeutic_modality: DEVICE
  description: >-
    Splints and orthoses can support positioning and function as part of an
    individualized plan. Device choice, duration, and goals depend on the joint,
    growth, skin tolerance, and etiologic pattern.
  treatment_term:
    preferred_term: orthotic device usage
  target_phenotypes:
  - preferred_term: Limb joint contracture
    term:
      id: HP:0003121
      label: Limb joint contracture
  - preferred_term: Limitation of joint mobility
    term:
      id: HP:0001376
      label: Limitation of joint mobility
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "splint support and orthotic fixation"
    explanation: >-
      The expert consensus explicitly includes splint and orthotic management.
- name: Ponseti-style manipulation and serial casting for arthrogrypotic clubfoot
  action_category: THERAPEUTIC
  therapeutic_modality: OTHER
  description: >-
    Ponseti-style manipulation and serial casting can be used as an initial
    clubfoot strategy. Small AMC cohorts show frequent initial correction but
    substantial relapse and later surgery, with poorer results in Amyoplasia
    than distal arthrogryposis. These data do not support a uniform outcome
    claim across all AMC.
  target_phenotypes:
  - preferred_term: Talipes equinovarus
    term:
      id: HP:0001762
      label: Talipes equinovarus
  evidence:
  - reference: PMID:37215511
    reference_title: Effectiveness of Ponseti technique in management of arthrogrypotic clubfeet - a prospective study.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "an initial correction was achieved in 13 out of 19 arthrogrypotic clubfeet (68.4%)."
    explanation: >-
      The small prospective cohort supports initial correction in a subset and
      provides a denominator that prevents overgeneralization.
  - reference: PMID:39342344
    reference_title: "Midterm clinical and radiological outcomes of arthrogryposis-associated clubfoot treated with the Ponseti method: a retrospective observational study and comprehensive literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Most of the studies reviewed (11 case series, 144 patients) reported high
      initial clinical correction rates, followed by high recurrence rates and
      the need for further surgeries.
    explanation: >-
      Midterm cohort data and the accompanying literature review support both
      initial benefit and the important relapse/surgery boundary.
- name: Selected orthopedic surgery
  action_category: THERAPEUTIC
  therapeutic_modality: SURGERY
  description: >-
    Joint- and pattern-specific orthopedic surgery may be considered when
    contractures or deformities substantially limit function and conservative
    measures are insufficient. Procedure choice and timing cannot be generalized
    across the AMC umbrella.
  treatment_term:
    preferred_term: surgical procedure
    term:
      id: NCIT:C15329
      label: Surgical Procedure
  target_phenotypes:
  - preferred_term: Limb joint contracture
    term:
      id: HP:0003121
      label: Limb joint contracture
  - preferred_term: Talipes equinovarus
    term:
      id: HP:0001762
      label: Talipes equinovarus
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "as well as orthopedic surgery."
    explanation: >-
      The consensus includes orthopedic surgery among management options without
      specifying one universal procedure.
- name: Etiology-specific genetic counseling
  action_category: COUNSELING_INFORMATIONAL
  description: >-
    Counseling should explain that AMC is a phenotype, review the identified or
    suspected underlying cause, and derive recurrence risk and reproductive
    options from that diagnosis. No single recurrence risk applies to AMC.
  treatment_term:
    preferred_term: genetic counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:6685864
    reference_title: "Fetal akinesia deformation sequence: an animal model."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      identification of the underlying pathologic process (etiology of the
      akinesia) to allow for proper classification and genetic counseling
    explanation: >-
      The source directly links etiologic classification, rather than the
      umbrella phenotype alone, to appropriate counseling.
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "ES significantly improves the diagnostic yield by providing key information for genetic counseling."
    explanation: >-
      The fetal cohort supports molecular etiologic information as an input to
      counseling.

discussions:
- discussion_id: interpretation_amc_is_a_descriptive_umbrella
  prompt: >-
    Should AMC be modeled as one genetic disease with a shared inheritance and
    gene list, or as a descriptive phenotype that triggers etiologic work-up?
  kind: INTERPRETATION
  status: RESOLVED
  attaches_to:
  - definitions#Multi-region congenital contracture definition
  - definitions#Etiologically heterogeneous clinical-syndrome definition
  - diagnosis#Etiology-directed cytogenomic and sequencing tests
  rationale: >-
    The defining criterion is phenotypic, authoritative consensus describes a
    clinical syndrome with complex etiology, and fetal cohorts resolve different
    chromosomal and sequence diagnoses in only subsets. This entry therefore
    intentionally omits umbrella-level inheritance and gene assertions.
  evidence:
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Arthrogryposis multiplex congenita (AMC) is a clinical syndrome with complex etiology."
    explanation: >-
      The consensus directly supports phenotype-first, etiology-second modeling.
  - reference: PMID:38856159
    reference_title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Thus, akin to CPSFS, both dominant and recessively inherited distal
      arthrogryposis can be caused by variants in MYH3.
    explanation: >-
      Even within one gene-associated distal group, different inheritance modes
      occur, illustrating why inheritance cannot be assigned to AMC generally.
- discussion_id: interpretation_fetal_akinesia_is_a_bounded_route
  prompt: >-
    Does fetal akinesia constitute a universal mechanism for every AMC case?
  kind: INTERPRETATION
  status: RESOLVED
  attaches_to:
  - pathophysiology#Etiology-specific fetal hypomobility or akinesia
  - pathophysiology#Movement-dependent joint development disruption
  rationale: >-
    Rat and chick immobilization experiments demonstrate that reduced movement
    can be sufficient to disrupt joint development and produce contractures.
    They do not establish that every clinically defined AMC case traverses this
    route, and clinical sources emphasize etiologic heterogeneity. The graph
    therefore marks this branch provisional and explicitly scoped.
  evidence:
  - reference: PMID:33771841
    reference_title: Joint development recovery on resumption of embryonic movement following paralysis.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      We demonstrate partial recovery of movement and partial recovery of joint
      development under both recovery conditions
    explanation: >-
      Controlled restoration of movement supports causality within the
      experimental model.
  - reference: PMID:40947408
    reference_title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Arthrogryposis multiplex congenita (AMC) is a clinical syndrome with complex etiology."
    explanation: >-
      Clinical heterogeneity prevents extrapolation of one model pathway to all
      AMC etiologies.
- discussion_id: gap_unsolved_etiology_after_current_testing
  prompt: >-
    Which causes account for AMC cases that remain unresolved after current
    cytogenomic and sequencing evaluation, and how should testing be prioritized
    across prenatal phenotype groups?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - diagnosis#Etiology-directed cytogenomic and sequencing tests
  rationale: >-
    Recent fetal cohorts report improved but incomplete and setting-specific
    diagnostic yields. Their ascertainment, phenotype mix, and testing sequence
    differ, so the percentages should not be converted into a universal expected
    yield or a fixed algorithm.
  evidence:
  - reference: PMID:40195522
    reference_title: "Perinatal genetic diagnostic yield in a population of fetuses with the phenotype arthrogryposis multiplex congenita: a cohort study 2007-2021."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The overall genetic diagnostic yield was 28% (18/64)"
    explanation: >-
      Most cases in this consecutive fetal cohort remained without a genetic
      diagnosis despite perinatal testing.
  - reference: PMID:41936055
    reference_title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      By exome sequencing, we identified causative variants in 14 of 42 families
      with negative karyotype and CNV results
    explanation: >-
      Sequential exome testing resolved a subset while leaving a substantial
      unsolved group.

references:
- reference: PMID:24459070
  title: Amyoplasia revisited.
- reference: PMID:38856159
  title: Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
- reference: PMID:40947408
  title: "[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)]."
- reference: PMID:41936055
  title: "Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families."
- reference: PMID:40195522
  title: "Perinatal genetic diagnostic yield in a population of fetuses with the phenotype arthrogryposis multiplex congenita: a cohort study 2007-2021."
- reference: PMID:41475428
  title: "Factors Associated With Functional Mobility in 256 Children With Arthrogryposis Multiplex Congenita: A Multicentric Cross-Sectional Study."
- reference: PMID:33771841
  title: Joint development recovery on resumption of embryonic movement following paralysis.
- reference: PMID:6685864
  title: "Fetal akinesia deformation sequence: an animal model."
- reference: PMID:33104047
  title: A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
- reference: PMID:37215511
  title: Effectiveness of Ponseti technique in management of arthrogrypotic clubfeet - a prospective study.
- reference: PMID:39342344
  title: "Midterm clinical and radiological outcomes of arthrogryposis-associated clubfoot treated with the Ponseti method: a retrospective observational study and comprehensive literature review."

notes: >-
  This umbrella entry intentionally omits prevalence, inheritance, and a gene
  list. Published occurrence estimates vary with case definition and setting,
  while inheritance and causal genes belong to the identified underlying
  diagnosis. Amyoplasia and distal arthrogryposis are retained as illustrative
  clinical-pattern branches, not an exhaustive taxonomy. The fetal-akinesia
  pathway is explicitly bounded to etiologies for which reduced movement is
  supported. Detailed gene-specific mechanisms and recurrence risks belong in
  dedicated etiologic disorder entries.
clinical_trials: []
datasets:
- accession: geo:GSE208171
  title: Loss of protein function of ZC4H2 gene causing severe phenotypes of female-restricted Wieacker Wolff Syndrome
  description: 'Background: Pathogenic variants of zinc finger C4H2-type containing (ZC4H2) on the X chromosome caused a group of genetic diseases called ZC4H2-associated rare disorders (ZARD), including Wieacker-Wolff Syndrome (WRWF) and Female-restricted Wieacker-Wolff Syndrome (WRWFFR). Patients displayed arthrogryposis multiplex congenita (AMC), central and peripheral nervous system involvement, as well as multiple dysmorphic features. The underlying mechanisms of the complex syndrome remain to be elucidated. Methods: Expression levels of ZC4H2 were knockdown in neural stem cells (NSCs) derived from induced pluripotent stem cells (iPSCs) by lentiviral-expressed shRNAs against ZC4H2.'
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: BULK_RNA_SEQ
  sample_count: 6
  notes: Identified by GEO DataSets index search for Arthrogryposis Multiplex Congenita (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-07-31. Title, sample count, and organism are GEO's own values.
📚

References & Deep Research

References

11
PMID:24459070
Amyoplasia revisited.
No top-level findings curated for this source.
PMID:38856159
Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis.
No top-level findings curated for this source.
PMID:40947408
[Expert consensus on the clinical diagnosis and management of Arthrogryposis multiplex congenita (2025 Edition)].
No top-level findings curated for this source.
PMID:41936055
Prenatal Diagnosis of Arthrogryposis Multiplex Congenita (AMC): Ultrasound and Genetic Findings in 69 Fetuses From 67 Unrelated Families.
No top-level findings curated for this source.
PMID:40195522
Perinatal genetic diagnostic yield in a population of fetuses with the phenotype arthrogryposis multiplex congenita: a cohort study 2007-2021.
No top-level findings curated for this source.
PMID:41475428
Factors Associated With Functional Mobility in 256 Children With Arthrogryposis Multiplex Congenita: A Multicentric Cross-Sectional Study.
No top-level findings curated for this source.
PMID:33771841
Joint development recovery on resumption of embryonic movement following paralysis.
No top-level findings curated for this source.
PMID:6685864
Fetal akinesia deformation sequence: an animal model.
No top-level findings curated for this source.
PMID:33104047
A review of the orthopedic interventions and functional outcomes among a cohort of 114 children with arthrogryposis multiplex congenita.
No top-level findings curated for this source.
PMID:37215511
Effectiveness of Ponseti technique in management of arthrogrypotic clubfeet - a prospective study.
No top-level findings curated for this source.
PMID:39342344
Midterm clinical and radiological outcomes of arthrogryposis-associated clubfoot treated with the Ponseti method: a retrospective observational study and comprehensive literature review.
No top-level findings curated for this source.

Deep Research

1
Arthrogryposis Multiplex Congenita Deep Research Fallback ▸

Arthrogryposis Multiplex Congenita Deep Research Fallback

Provider Attempts

  • 2026-05-13: Automated deep-research providers (falcon, asta, cyberian-codex, perplexity, openai) were unavailable in the curation environment for this disorder. No provider-generated research artifact was produced.

No provider-generated research artifact was available to integrate. Curation therefore proceeded from a manual literature synthesis built around the canonical AMC clinical and molecular references listed below, without hand-editing any references_cache/*.md files.

Evidence Scope Used For Curation

  • PMID:24459070 (Hall JG, Amyoplasia revisited) — the canonical 560-patient Amyoplasia case series. Provides the foundational clinical description of Amyoplasia, supports its sporadic recurrence pattern, documents the characteristic symmetric limb positioning (extended elbows, equinovarus feet), and reports fatty-fibrous replacement of muscle. Used for the Amyoplasia subtype, the Sporadic inheritance entry, the Congenital contracture / Limb joint contracture / Talipes equinovarus phenotypes, and the Clinical pattern recognition diagnostic entry.
  • PMID:24459095 (Hall JG, Amyoplasia involving only the upper limbs or only the lower limbs) — complementary differential-diagnosis paper for Amyoplasia; included in references: as background for the Amyoplasia clinical group.
  • PMID:27587986 (Hall JG, Kiefer J, Arthrogryposis as a Syndrome: Gene Ontology Analysis) — synthesis paper explicitly framing decreased in utero fetal movement (fetal akinesia) as the shared mechanistic pathway across all genetic AMC subtypes. Anchors the "Decreased fetal movement" pathophysiology node and the Decreased fetal movement phenotype.
  • PMID:25256237 (Beck AE et al., Genotype-phenotype relationships in Freeman-Sheldon syndrome) — 46-family DA2A series. Establishes MYH3 as causative for Freeman-Sheldon syndrome (DA2A) and quantifies the three recurrent missense variants (p.T178I, p.R672C, p.R672H) that account for the majority of DA2A cases. Used for the Heterozygous MYH3 variants genetic entry.
  • PMID:38856159 (Morali et al., Bi-allelic variants in MYH3 cause recessively-inherited arthrogryposis) — extends MYH3 from a purely dominant gene (Freeman-Sheldon, Sheldon-Hall, multiple pterygium) to a recessive cause of distal arthrogryposis. Provides the standard "two-or-more body areas" clinical definition of arthrogryposis used in the Congenital contracture and Arthrogryposis multiplex congenita phenotype entries, the Autosomal recessive inheritance entry, and the Exome / genome sequencing diagnostic entry.
  • PMID:30285720 (Li B et al., Novel mutations in TPM2 and PIEZO2 are responsible for distal arthrogryposis (DA) 2B and mild DA in two Chinese families) — provides a heterozygous TPM2 missense variant segregating with DA2B (Sheldon-Hall syndrome) in a multigenerational family. Used for the Heterozygous TPM2 variants genetic entry. The same paper performs linkage analysis with markers at TPM2, TNNI2/TNNT3, and TNNC2, which is used as PARTIAL evidence for the Heterozygous TNNI2 variants entry (which carries an Associated association rather than Causative, pending addition of a dedicated TNNI2 causative-variant citation in a future revision).
  • PMID:32799913 (Guo P et al., Drosophila myosin DA1/DA2B models) — the mechanistic paper supporting prolonged actomyosin interactions as the proximal sarcomeric defect in DA1 and DA2B. Tagged with evidence_source: MODEL_ORGANISM for the sarcomeric contractile-protein dysfunction pathophysiology node and for the autosomal dominant inheritance characterization (their introduction frames the DAs as autosomal dominant skeletal muscle diseases).
  • PMID:31479584 (Shriners multiauthored review, Treatment and outcomes of arthrogryposis in the lower extremity) — anchors early intensive physiotherapy and bracing as the central, evidence-supported management for AMC, and emphasizes a multidisciplinary care model.
  • PMID:22875688 (Lampasi et al., Management of knee deformities in children with arthrogryposis) — enumerates the orthopedic surgical procedures (soft-tissue release, femoral shortening-extension osteotomy, Ilizarov gradual correction, femoral anterior epiphysiodesis) used to address residual knee contractures in AMC.

Literature Synthesis

Arthrogryposis Multiplex Congenita (AMC) is an umbrella clinical phenotype — defined by congenital joint contractures involving two or more different body areas — rather than a single disease (PMID:38856159). The condition is etiologically heterogeneous and includes more than 400 recognized genetic disorders together with the sporadic, classical form Amyoplasia (PMID:24459070). Across all forms, the most consistent unifying mechanistic feature is decreased in utero fetal movement: "All types of arthrogryposis have decreased in utero fetal movement." (PMID:27587986). Persistent fetal hypokinesia prevents normal stretching of muscle and periarticular connective tissue, producing fixed congenital contractures, fatty-fibrous replacement of muscle, characteristic limb positioning (extended elbows, equinovarus feet), and the broader fetal akinesia deformation sequence findings (PMID:24459070, PMID:27587986).

Clinically, AMC is divided into four major groups. Amyoplasia, the most common single form, is sporadic, "completely sporadic" in Hall's 560-patient series (PMID:24459070), and is characterized by symmetric severe limb contractures, fatty-fibrous muscle replacement, characteristic limb positioning, and typically preserved cognition; it remains "a clinical diagnosis at this time" (PMID:24459070). The distal arthrogryposis (DA) syndromes are typically autosomal dominant disorders preferentially affecting the hands and feet, including DA1, DA2A (Freeman-Sheldon, the most severe), and DA2B (Sheldon-Hall) (PMID:25256237, PMID:32799913). The multiple pterygium syndromes combine congenital contractures with pterygia across flexural joints and include the autosomal recessive Escobar variant and the lethal multiple pterygium syndrome. The lethal congenital contracture syndromes (LCCS) are prenatal- or perinatal-lethal disorders in the fetal akinesia deformation sequence spectrum.

Molecularly, the dominant DA syndromes are caused predominantly by heterozygous variants in genes encoding sarcomeric contractile proteins. MYH3 (embryonic myosin heavy chain) is the most common single gene cause: "Heterozygous variants in MYH3 have been identified to cause the dominantly-inherited distal arthrogryposis conditions, Freeman-Sheldon syndrome, Sheldon-Hall syndrome, and multiple pterygium syndrome." (PMID:38856159). In Beck et al.'s 46-family DA2A series, "MYH3 mutations were found in 43/46 (93%) kindreds, with three mutations (p.T178I, p.R672C, and p.R672H) explaining 39/43 (91%) of cases." (PMID:25256237). MYH3 also underlies a recessive form of distal arthrogryposis (PMID:38856159). Heterozygous TPM2 (beta-tropomyosin) variants cause DA2B and related distal arthrogryposis phenotypes (PMID:30285720). TNNI2 (fast skeletal troponin I) is grouped with TPM2 in the thin-filament regulatory cluster of distal arthrogryposis candidate loci (PMID:30285720); the present entry classifies TNNI2 with association: Associated and a PARTIAL evidence tag, because the Li et al. paper used TNNI2 as a linkage candidate locus rather than itself demonstrating a pathogenic TNNI2 variant. Functional Drosophila modeling demonstrates that DA1 and DA2B sarcomeric variants produce prolonged actomyosin interactions, which plausibly reduces effective fetal movement and produces the congenital contracture phenotype (PMID:32799913).

Management of AMC is lifelong and multidisciplinary, centered on early intensive physiotherapy and orthotic bracing: "The importance of very early and aggressive management of these deformities in the form of intensive physiotherapy (with its various modalities) and bracing is emphasized." (PMID:31479584). Selective orthopedic surgical procedures — soft-tissue release, femoral shortening-extension osteotomy, gradual correction with Ilizarov frames, and femoral anterior epiphysiodesis — address residual contractures not corrected by conservative measures (PMID:22875688). Care delivery emphasizes "the central role of a multidisciplinary approach involving all stakeholders, especially the families" (PMID:31479584). Genetic counseling is integral, given the sporadic nature of Amyoplasia and the autosomal dominant or recessive recurrence risks in the Mendelian forms.

Curation Conclusions

The accepted unifying model of AMC is decreased in utero fetal movement (fetal akinesia) producing fixed congenital joint contractures across two or more body areas. The mechanism is gene-agnostic at the level of the final common pathway, but converges from many proximal causes — most prominently sarcomeric contractile-protein dysfunction in the distal arthrogryposes (MYH3, TPM2, TNNI2). The dismech graph therefore models three pathophysiology nodes (decreased fetal movement, sarcomeric contractile-protein dysfunction, congenital joint contracture formation) linked by downstream edges that capture the conserved final-common pathway. Subtype assignment is clinically anchored (Amyoplasia, distal arthrogryposis, multiple pterygium syndromes, LCCS) and is informed by contracture distribution, associated craniofacial and prenatal features, and family history, with exome / genome sequencing used to identify causative Mendelian variants. Detailed gene-specific pathophysiology and management belong in dedicated subtype entries; the present entry itemizes only the most informative thin- and thick-filament DA genes (MYH3, TPM2, TNNI2).