Arthrochalasia Ehlers–Danlos Syndrome: Disease Characteristics Report

Scope and evidence note. Arthrochalasia Ehlers–Danlos syndrome (aEDS) is so rare that most evidence consists of molecularly confirmed case reports, small series, expert consensus, and one 2022 systematic review. Approximately 42 patients had been published worldwide by 2022; consequently, frequencies should not be interpreted as stable population estimates. Claims based on EDS generally rather than aEDS specifically are explicitly labeled as indirect evidence. No substantive aEDS-specific publications from 2023–2024 were identified; the principal recent development is a 2024 EDS-wide review showing that orthopedic surgical evidence remains sparse and inconsistent. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 1-2, schubart2024outcomesoforthopaedic pages 1-2)

The following table provides a compact, ontology-oriented summary before the detailed report.

Table: Compact extraction table summarizing the identity, genetics, mechanism, phenotype, epidemiology, diagnosis, management, vascular evidence, and research gaps for arthrochalasia Ehlers–Danlos syndrome.

1. Disease information

Definition and classification

Arthrochalasia EDS is an autosomal-dominant Mendelian connective-tissue disorder caused by abnormal processing of type I procollagen. Its defining manifestations are congenital—usually bilateral—hip dislocation, severe generalized joint hypermobility, recurrent joint dislocations or subluxations, and hyperextensible or fragile skin. It is one of the 13 subtypes recognized by the 2017 International EDS Classification. (malfait2017the2017international pages 12-13, islam2021ehlersdanlossyndromeimmunologic pages 31-33)

A useful exact abstract statement from the 2022 systematic review is: “Ehlers–Danlos syndrome type arthrochalasia (aEDS) is a rare genetic disease characterized by severe generalized joint hypermobility, bilateral congenital hip dislocation, skin hyperextensibility, muscle hypotonia, and mild dysmorphic features.” The same abstract states: “Only about 42 cases have been published worldwide.” The article was published 7 February 2022; DOI URL: https://doi.org/10.3390/ijerph19031870. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 1-2)

Identifiers and synonyms

• MONDO: MONDO:0007525, Ehlers-Danlos syndrome, arthrochalasia type.
• OMIM: commonly divided historically into EDS type VIIA (COL1A1-related; OMIM phenotype 130060) and EDS type VIIB (COL1A2-related; OMIM phenotype 130060 is often used for the arthrochalasia phenotype in aggregated resources; database implementations should be checked for version-specific mapping).
• Orphanet: Arthrochalasia Ehlers–Danlos syndrome; ORPHA mappings should be version-validated before ingestion because legacy VIIA/VIIB records may be handled differently.
• ICD-10: no dedicated aEDS code; generally coded under Q79.6, Ehlers–Danlos syndrome.
• ICD-11: under the Ehlers–Danlos syndrome/heritable connective-tissue disorder hierarchy; no reliably retrieved subtype-specific code should be asserted without checking the current ICD-11 release.
• MeSH: Ehlers-Danlos Syndrome; no separate aEDS MeSH descriptor was established in the retrieved evidence.
• Synonyms: arthrochalasia EDS; EDS arthrochalasia type; Ehlers–Danlos syndrome type VIIA; EDS VIIA; Ehlers–Danlos syndrome type VIIB; EDS VIIB; arthrochalasis multiplex congenita. The VIIA/VIIB distinction respectively denotes COL1A1- and COL1A2-related disease. (malfait2017the2017international pages 12-13, wenstrup2002prevalenceofaortic pages 1-2)

This report is built from aggregated disease-level resources and published human cases, not individual EHR records. Open Targets independently associates MONDO:0007525 with COL1A1 and COL1A2 and links supporting human literature including PMIDs 18409203, 9295084, 1867198, 8071956, and 19594296. (OpenTargets Search: arthrochalasia Ehlers-Danlos syndrome-COL1A1,COL1A2)

2. Etiology

Causal factors and genetic risk

The primary cause is a heterozygous germline pathogenic variant in COL1A1 or COL1A2 that produces complete or partial loss of exon 6 from the mature transcript. Exon 6 encodes functionally critical portions of the type I procollagen N-terminal processing region. Both inherited and de novo cases occur; one reviewed case had a de novo COL1A1 exon-skipping variant. (malfait2017the2017international pages 12-13, martinmartin2022ehlers–danlossyndrometype pages 7-8, malfait2020theehlers–danlossyndromes pages 6-7)

Relevant gene annotations are:

• COL1A1 — collagen type I α1 chain; HGNC:2197; NCBI Gene 1277; chromosome 17q21.33.
• COL1A2 — collagen type I α2 chain; HGNC:2198; NCBI Gene 1278; chromosome 7q21.3. (OpenTargets Search: arthrochalasia Ehlers-Danlos syndrome-COL1A1,COL1A2, martinmartin2022ehlers–danlossyndrometype pages 2-4)

Because the disorder is monogenic and highly penetrant clinically in reported families, the principal risk factor is carrying the causal allele or having an affected parent. Family history may be absent because of a de novo event. No validated susceptibility loci, common-variant polygenic risk score, or modifier gene has been established.

Environmental, lifestyle, infectious, and protective factors

No environmental toxin, infection, diet, smoking exposure, occupation, sex, or lifestyle factor is known to cause aEDS. Mechanical stress does not initiate the disorder but can expose the genetically weakened tissue phenotype by precipitating dislocation, soft-tissue injury, bruising, and pain. This is a gene–mechanical-environment interaction at the level of manifestations, not a demonstrated interaction affecting mutation penetrance.

No protective allele or environmental exposure has been established. Joint protection, appropriately dosed strengthening, avoidance of high-impact/contact activity, and prevention of unnecessary tissue trauma are complication-reduction strategies, not protection against inheriting or developing aEDS.

3. Phenotypes

Core and minor manifestations

The 2017 criteria define three major features: (1) congenital bilateral hip dislocation, (2) severe generalized joint hypermobility with multiple dislocations or subluxations, and (3) skin hyperextensibility. Minor criteria are muscular hypotonia, kyphoscoliosis, radiologically mild osteopenia, tissue fragility including atrophic scars, and easy bruising. Foot deformities and congenital knee dislocation are also reported. (malfait2017the2017international pages 12-13, yonko2021orthopedicconsiderationsand pages 2-3, martinmartin2022ehlers–danlossyndrometype pages 5-7, giunta2008thearthrochalasiatype pages 2-3)

The disease’s extreme rarity precludes reliable percentage estimates for most manifestations. The major exception is the historical observation that bilateral congenital hip dislocation was present in all published patients informing the 2017 criteria. Reports of very low fracture incidence argue against automatically equating mild osteopenia in aEDS with the fracture burden of osteogenesis imperfecta. (malfait2017the2017international pages 12-13, martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 5-7)

Quality of life

No validated aEDS-specific EQ-5D, SF-36, PROMIS, or disease-specific quality-of-life cohort was identified. Likely burdens—supported clinically but not quantified specifically for aEDS—include impaired mobility, need for orthoses or assistive devices, recurrent injuries, chronic pain, limitations in self-care and employment, and procedural anxiety. The 2022 review states that treatment focuses on improving quality of life, but does not report response rates or standardized scores. (martinmartin2022ehlers–danlossyndrometype pages 1-2)

4. Genetic and molecular information

Pathogenic variant class and consequences

Causal variants are usually splice-donor or splice-acceptor changes, intragenic deletions, or other variants that cause in-frame complete or partial exon-6 skipping. An experimentally characterized example was COL1A1 IVS5-2A>T—legacy nomenclature—which activated a cryptic splice site and removed the first 15 nucleotides of exon 6. This deleted five amino acids including the procollagen N-proteinase cleavage site. Modern HGVS nomenclature should be generated against the transcript used by the testing laboratory rather than inferred from this legacy description. (giunta2008thearthrochalasiatype pages 2-3)

These are germline heterozygous variants. Somatic mosaic disease is not an established mechanism. Pathogenicity should be assigned under ACMG/AMP criteria using segregation/de novo evidence, RNA evidence demonstrating exon loss, collagen biochemical evidence, absence or extreme rarity in population databases, and phenotype specificity. Exact allele frequencies were unavailable in the retrieved papers, but fully penetrant causal alleles for a disorder this rare are expected to be absent or exceptionally rare in gnomAD; this expectation is not a substitute for variant-level database checking.

The functional mechanism is best described as structural loss with dominant interference rather than simple haploinsufficiency. Mutant chains enter heterotrimeric type I collagen molecules: approximately three quarters of molecules may be affected for an abnormal α1(I) chain and approximately half for an abnormal α2(I) chain. That provides a plausible explanation for reports that COL1A1-related disease can be more severe, although robust genotype–phenotype statistics are unavailable. Dominant-negative interference is strongly inferred from chain incorporation and abnormal fibrils, but was not directly tested as a separate experimental endpoint in the cited ultrastructural study. (martinmartin2022ehlers–danlossyndrometype pages 7-8, giunta2008thearthrochalasiatype pages 1-2)

No reproducible modifier genes, epigenetic signature, pathogenic aneuploidy, translocation, repeat expansion, mitochondrial lesion, or large chromosomal syndrome is established for aEDS. Copy-number variants restricted to the relevant exon or splice architecture remain plausible and justify deletion/duplication analysis after negative sequencing.

5. Environmental information

There is no evidence for causal pollutants, radiation, occupational agents, toxins, dietary deficiencies, alcohol, smoking, or infectious agents. Therefore CTD/toxicogenomic and pathogen annotations should be not applicable/unsupported. High-impact activity, forceful manipulation, poor joint positioning, and surgery can aggravate manifestations in genetically fragile tissues; they should be represented as complication triggers, not disease causes. A 2024 chiropractic case illustrates that forceful manipulation can worsen pain and inflammation in EDS, but the patient was not molecularly established to have aEDS, so this is indirect evidence only. (lucente2024chiropractictreatmentof pages 1-2)

6. Mechanism and pathophysiology

Ordered causal chain

1. A heterozygous germline COL1A1 or COL1A2 splice/deletion lesion leads to partial or complete skipping of exon 6. (Demonstrated in human cases.) (giunta2008thearthrochalasiatype pages 2-3, malfait2020theehlers–danlossyndromes pages 6-7)
2. Exon-6 loss leads to deletion of the N-proteinase cleavage site and may also remove the N-telopeptide cross-linking lysine and first Gly-X-Y helical triplet. (Demonstrated by sequence/protein analysis.) (malfait2020theehlers–danlossyndromes pages 6-7, brady2017theehlers–danlossyndromes pages 8-9)
3. Loss of the cleavage site results in failure to remove the type I procollagen N-propeptide, producing pNα1(I)- or pNα2(I)-containing collagen. (Demonstrated by fibroblast collagen electrophoresis.) (giunta2008thearthrochalasiatype pages 2-3, giunta2008thearthrochalasiatype pages 1-2)
4. Incorporation of uncleaved mutant chains leads to disturbed extracellular collagen-I fibrillogenesis. Dominant interference is strongly inferred from the proportion of affected heterotrimers and fibril abnormalities rather than proven in an isolated perturbation experiment. (giunta2008thearthrochalasiatype pages 1-2)
5. Disturbed fibrillogenesis results in smaller, loosely/randomly organized collagen fibrils with irregular or ragged contours in skin dermis. (Demonstrated by transmission electron microscopy.) (giunta2008thearthrochalasiatype pages 2-3, giunta2008thearthrochalasiatype pages 1-2)
6. Abnormal collagen architecture leads to reduced tensile and stabilizing competence of ligaments, joint capsules, skin, tendon, and bone connective tissue. (Mechanistically inferred from tissue function and concordant human phenotype.)
7. Ligament/joint-capsule weakness leads to congenital hip dislocation, severe generalized hypermobility, recurrent dislocations, and deformity; skin/dermal weakness leads to hyperextensibility, bruising, fragility, and atrophic scars; musculoskeletal matrix weakness leads to hypotonia-associated motor impairment, kyphoscoliosis, and mild osteopenia. (Human clinical association; intermediate biomechanics partly inferred.) (malfait2017the2017international pages 12-13, martinmartin2022ehlers–danlossyndrometype pages 5-7, giunta2008thearthrochalasiatype pages 2-3)

Cellular and biochemical detail

The best direct cellular evidence comes from cultured dermal fibroblasts. Patient fibroblasts synthesize abnormal longer α(I) chains retaining their N-propeptide, demonstrable by SDS-PAGE and collagen-fraction analyses. Historical reports of only 10–40% normal “converting proteinase” activity were subsequently reinterpreted after mutant pNα2(I) chains were identified: the primary lesion is substrate structure/processing, not necessarily reduced enzyme production. (giunta2008thearthrochalasiatype pages 2-3, brady2017theehlers–danlossyndromes pages 8-9)

No primary Wnt, MAPK, mTOR, PI3K–AKT, immune, autophagy, apoptosis, mitochondrial, or metabolic pathway defect is established. ER stress is a recognized mechanism in some structural extracellular-matrix diseases, but has not been demonstrated as aEDS-specific pathology and should not be curated as established. Likewise, no aEDS-specific transcriptomic, proteomic, metabolomic, lipidomic, single-cell, spatial-transcriptomic, CRISPR-screen, or multi-omics signature was identified. (lamande2020geneticdisordersof pages 1-2)

Suggested ontology annotations include GO: extracellular matrix organization; collagen fibril organization; collagen biosynthetic process; protein processing; extracellular structure organization. Relevant cellular components are collagen-containing extracellular matrix and collagen trimer. Suggested Cell Ontology labels are fibroblast (CL:0000057), dermal fibroblast, osteoblast, tenocyte, and ligament fibroblast; only dermal fibroblasts were directly studied, whereas the latter cell types are anatomically plausible but not directly profiled.

7. Anatomical structures affected

• Primary organ/system level: musculoskeletal system—hips, knees, shoulders and other synovial joints; axial skeleton; feet; bone. Integumentary system—skin and scars.
• Tissue level: ligament, joint capsule, tendon, dermis, bone extracellular matrix, fascia and other collagen-I-rich connective tissues.
• Cell level: fibroblasts are directly demonstrated; osteoblasts, tenocytes and ligament/joint-capsule fibroblasts are inferred relevant collagen producers.
• Subcellular level: COL1A1/COL1A2 transcription and splicing occur in the nucleus; procollagen synthesis and assembly occur in rough ER/Golgi; extracellular N-propeptide processing and fibrillogenesis occur in the extracellular space. Only the extracellular processing/fibril defect and fibroblast collagen products are directly demonstrated in aEDS.
• Secondary cardiovascular involvement: rare vascular complications and isolated valvular regurgitation have been reported, but aEDS is not classified as vascular EDS. (dhondt2018vascularphenotypesin pages 3-4, martinmartin2022ehlers–danlossyndrometype pages 4-5)

Suggested UBERON labels are hip joint, knee joint, synovial joint, skin of body, dermis, tendon, ligament, bone tissue and extracellular matrix. Hip involvement is usually bilateral; other dislocations may be bilateral, unilateral, or asymmetric.

8. Temporal development

Onset is prenatal/congenital. Breech presentation, polyhydramnios, premature rupture of membranes, reduced fetal movement, prematurity, and congenital joint dislocations have been reported. Neonates may have severe hypotonia, generalized hypermobility, large fontanelles and mild dysmorphism. (martinmartin2022ehlers–danlossyndrometype pages 7-8)

The condition is chronic and lifelong, without recognized remission. Hypotonia and apparent hypermobility may lessen with age, but orthopedic instability, recurrent injury, spinal deformity, pain, and scar burden may persist or accumulate. Mental development was normal in reported patients. Published observations span prenatal life through adulthood, but there is no validated stage system or reliable progression rate. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 4-5)

Critical intervention periods are:

1. Prenatal/perinatal: obstetric monitoring because of malpresentation, membrane rupture and prematurity.
2. Neonatal/infancy: early recognition and careful management of hip/knee dislocation, hypotonia and clubfoot.
3. Growth: prevention and monitoring of scoliosis, recurrent instability and deconditioning.
4. Before surgery or pregnancy: individualized tissue-fragility, bleeding, wound-healing, positioning and anesthetic planning. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 4-5)

9. Inheritance and population

Inheritance is autosomal dominant. Each child of an affected heterozygous individual has a 50% probability of inheriting the variant, subject to confirmation that the parent is heterozygous and excluding mosaicism. Both sexes are expected to be affected equally; no sex-specific penetrance is established. Expressivity is variable, including possible COL1A1-versus-COL1A2 severity differences. No genetic anticipation is expected because this is not a repeat-expansion disorder. (malfait2017the2017international pages 12-13, martinmartin2022ehlers–danlossyndrometype pages 7-8)

Population prevalence and annual incidence are unknown. The strongest available statistic is approximately 42 published patients worldwide by 2022. This is a literature count, not prevalence. Aggregate EDS estimates—including 1:5,000 or EDS/hypermobility-code prevalence from national EHR studies—must not be assigned to aEDS. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 1-2)

No founder effect, ancestry enrichment, geographic concentration, carrier frequency, or role for consanguinity has been established. Consanguinity is not expected to be a major determinant for an autosomal-dominant disorder. Parental germline mosaicism is biologically possible in an apparently de novo case, but an aEDS-specific recurrence rate was not found.

10. Diagnostics

Clinical criteria

The 2017 minimum criteria suggestive of aEDS are:

• congenital bilateral hip dislocation; and
• either skin hyperextensibility or severe generalized joint hypermobility with multiple dislocations/subluxations; and
• at least two minor criteria: hypotonia, kyphoscoliosis, mild radiographic osteopenia, tissue fragility/atrophic scars, or easy bruising.

A definitive diagnosis requires identification of a causal COL1A1 or COL1A2 variant producing complete or partial exon-6 loss. Clinical criteria alone are insufficient because of overlap with other EDS and skeletal dysplasia phenotypes. (malfait2017the2017international pages 12-13)

Recommended testing algorithm

1. Document congenital hip status, generalized hypermobility, dislocation history, skin/scar findings, hypotonia, spine/foot deformity, bruising and family history.
2. Perform sequencing of COL1A1 and COL1A2, preferably through a validated EDS/heritable connective-tissue-disorder panel that includes splice boundaries and permits phenotype-based differential diagnosis.
3. If negative, perform exon-level deletion/duplication/CNV analysis and review coverage of exon 6 and adjacent intronic regions.
4. For a candidate splice variant, use RNA studies where possible to demonstrate partial or complete exon-6 loss.
5. If panel testing is unrevealing despite a compelling phenotype, WES or WGS can identify atypical intronic/structural lesions or an alternative diagnosis. WGS is especially useful for noncoding splice and structural variants; neither WES nor WGS replaces functional splice interpretation.
6. Segregation and parental testing distinguish inherited from de novo disease and support recurrence counseling.

CMA, karyotyping, FISH, mitochondrial DNA testing and repeat-expansion testing are not routine aEDS tests unless another diagnosis is suspected.

Ancillary tests

Cultured skin-fibroblast collagen analysis can identify abnormal pN-collagen chains. Skin-biopsy transmission electron microscopy may reveal small, irregular, ragged and disorganized collagen fibrils and can provide supportive evidence, including possible distinction in severity between VIIA and VIIB; it does not replace molecular confirmation. (giunta2008thearthrochalasiatype pages 2-3, giunta2008thearthrochalasiatype pages 1-2)

Clinical evaluation may include hip/spine/foot radiography, bone-density assessment when clinically indicated, echocardiography based on baseline evaluation or symptoms, and vascular imaging only when individualized risk or clinical findings justify it. There is no validated circulating biomarker, enzyme assay, liquid biopsy, electrophysiologic signature, or omics-based diagnostic test.

Differential diagnosis

• Other EDS subtypes: especially classical, classical-like, dermatosparaxis, kyphoscoliotic, musculocontractural and spondylodysplastic EDS; distinguish by molecular testing and subtype-specific skin, vascular, craniofacial or congenital-contracture findings.
• Osteogenesis imperfecta/COL1-related overlap disorder: fracture burden, blue sclerae and dentinogenesis imperfecta favor OI, although overlap occurs.
• Larsen syndrome: multiple congenital large-joint dislocations and characteristic craniofacial/skeletal findings; FLNB testing.
• Loeys–Dietz syndrome: arterial aneurysm/tortuosity and craniofacial findings; TGF-β-pathway genes.
• Cutis laxa syndromes: lax rather than hyperextensible/recoiling skin and subtype-specific systemic disease.
• Congenital hip dysplasia, Marfan syndrome, FLNA-related disorders, and neuromuscular hypotonia syndromes. The aEDS systematic review specifically highlights Larsen, Loeys–Dietz and cutis laxa syndromes. (martinmartin2022ehlers–danlossyndrometype pages 7-8)

No population newborn screen exists. Appropriate screening is phenotype-triggered testing and cascade testing of relatives after a familial variant is established.

11. Outcome and prognosis

No 5- or 10-year survival estimates, disease-specific mortality rate, or validated life-expectancy estimate exists. Available evidence does not show the severe arterial-rupture mortality pattern characteristic of vascular EDS. One systematic review found a vascular complication in 1 of 17 aEDS patients (6%), and a case report described progressive mitral, aortic and tricuspid regurgitation; both findings warrant awareness but are too sparse to quantify lifetime risk. (dhondt2018vascularphenotypesin pages 3-4, martinmartin2022ehlers–danlossyndrometype pages 4-5)

One neonatal death in a baby born at 35 weeks was included in the 2022 review, but the evidence does not establish a general neonatal mortality rate. Intellectual development is generally normal. Fractures appear uncommon despite mild osteopenia in some patients. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 5-7)

Principal morbidity is orthopedic and functional: congenital hip disease, recurrent instability/dislocation, spinal and foot deformity, pain, impaired mobility, skin injury, bruising and surgical/wound complications. Recovery from an individual dislocation or operation is possible, but the underlying collagen defect and lifelong predisposition do not resolve. Prognostic factors have not been validated; plausible factors include variant/gene, severity of congenital instability, scoliosis, recurrent trauma, muscle conditioning and access to specialist care.

12. Treatment

Current strategy

There is no approved curative, gene, RNA, cell, enzyme-replacement, targeted, or disease-modifying treatment. The 2022 review’s abstract states: “Treatment is currently symptomatic and focuses on increasing the quality of life of these patients, as there is no curative treatment.” (martinmartin2022ehlers–danlossyndrometype pages 1-2)

Management should be multidisciplinary and individualized:

• Physiotherapy/rehabilitation: low-impact strengthening, proprioceptive training, postural and gait work, and prevention of deconditioning; avoid forceful end-range maneuvers. Suggested NCIT terms: Physical Therapy, Rehabilitation Therapy.
• Occupational therapy and joint protection: activity modification, ergonomic support, adaptive equipment and fatigue management. NCIT: Occupational Therapy, Supportive Care.
• Orthoses and mobility aids: braces, splints, footwear, walking aids or wheelchairs according to instability and function. NCIT: Orthotic Device, Assistive Device.
• Pain management: multimodal nonpharmacologic care; acetaminophen or appropriately selected analgesics as clinically indicated. No aEDS-specific drug-response or pharmacogenomic data exist. NCIT: Pain Management, Analgesic Therapy.
• Skin/wound care: minimize trauma and adhesive injury; careful closure, prolonged support where appropriate, and monitoring for delayed healing or hematoma. NCIT: Wound Care.
• Orthopedic intervention: early specialist assessment of congenital hip/knee dislocation, clubfoot and progressive deformity; surgery only after careful risk–benefit evaluation and when conservative care is inadequate. NCIT: Orthopedic Surgery, Joint Stabilization Procedure.
• Cardiac/vascular care: symptom-driven or individualized surveillance; standard cardiology management for documented valve or vascular disease.
• Pregnancy: high-risk obstetric planning, careful positioning and attention to malpresentation, premature membrane rupture, tissue fragility and postpartum injury. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 4-5)

Surgical evidence and 2024 development

The October 2024 EDS-wide scoping review found 71 primary orthopedic studies from 1990–2023—38 single case reports, 14 case series and 19 retrospective cohorts—and no randomized trials. Outcomes were inconsistent, and no reliable long-term benefit or aEDS-specific protocol could be established. (schubart2024outcomesoforthopaedic pages 1-2)

A retrospective EDS surgical cohort reported 290 postoperative complications after 320 procedures, with a complication recorded in 91% of cases; however, subtype assignment was unreliable and these data cannot be directly converted into an aEDS risk estimate. General concerns include persistent instability/pain, fixation failure, bleeding, infection, poor wound healing and reoperation. These findings support cautious planning, not avoidance of all necessary surgery. (schubart2024outcomesoforthopaedic pages 15-16, yonko2021orthopedicconsiderationsand pages 1-1, yonko2021orthopedicconsiderationsand pages 6-6)

The ClinicalTrials.gov search retrieved no relevant aEDS-specific interventional trial. No NCT identifier, response rate, or treatment-related adverse-event series specific to aEDS was identified.

13. Prevention

Primary prevention: The occurrence of a de novo pathogenic variant cannot currently be prevented. For known familial disease, reproductive options include genetic counseling, prenatal diagnosis and preimplantation genetic testing for the established familial variant. These prevent or inform transmission risk; they are not therapies.

Secondary prevention: Early diagnosis in an infant with bilateral hip dislocation, severe hypermobility and hypotonia permits appropriate handling, orthopedic care, avoidance of damaging procedures, and cascade testing. There is no population newborn screening or routine carrier screening because aEDS is autosomal dominant and exceptionally rare.

Tertiary prevention: Joint-protection education, safe strengthening, appropriate bracing, fall prevention, avoidance of high-impact/contact activities, cautious manual therapy, skin protection, dental and surgical planning, monitoring of deformity and individualized cardiac assessment aim to reduce complications. Vaccination, antimicrobial prophylaxis and environmental remediation have no disease-specific preventive role.

Genetic counseling should explain the 50% transmission risk from a heterozygous affected parent, variable expressivity, possibility of a de novo variant, and residual recurrence risk from parental mosaicism.

14. Other species and natural disease

No naturally occurring animal disorder was identified that is securely established as the direct orthologue of human aEDS caused by a heterozygous COL1A1 or COL1A2 exon-6 lesion. EDS-like diseases occur in dogs and other domestic species, but retrieved canine evidence concerned ADAMTS2-related dermatosparaxis, not arthrochalasia; it must not be curated as an aEDS model. (lamande2020geneticdisordersof pages 1-2)

Relevant conserved orthologues include mouse Col1a1/Col1a2, rat Col1a1/Col1a2, zebrafish col1a1a/col1a1b/col1a2, and canine COL1A1/COL1A2. The collagen-I processing pathway is evolutionarily conserved, but an exact spontaneous veterinary aEDS genotype–phenotype relationship was not established in the retrieved literature. There is no infectious transmission, zoonotic potential or cross-species contagion.

15. Model organisms and experimental systems

The most disease-proximal established experimental system is patient-derived cultured dermal fibroblasts, which reproduce abnormal transcript processing and secretion/incorporation of pN-collagen. Skin-biopsy transmission electron microscopy directly demonstrates abnormal fibril architecture. These systems are suitable for RNA-splicing assays, collagen electrophoresis, extracellular-matrix imaging and testing splice-correction concepts. (giunta2008thearthrochalasiatype pages 2-3, giunta2008thearthrochalasiatype pages 1-2)

A 2014 mouse was described as a model of combined osteogenesis imperfecta and EDS, but its variants were outside collagen exon 6. It is therefore mechanistically adjacent, not an exact aEDS model, and should not be annotated as fully recapitulating arthrochalasia EDS.

No validated exon-6 aEDS knock-in mouse, rat, zebrafish, Drosophila, organoid, iPSC, humanized model, or CRISPR functional-genomics screen was identified. A high-priority model would be a heterozygous splice-site or precise exon-6 deletion knock-in in Col1a1 or Col1a2, assessed for pN-collagen retention, fibril ultrastructure, congenital hip instability, generalized laxity, skin mechanics and bone phenotype. Its limitations would include species-specific hip development and difficulty quantifying subjective pain and disability.

Evidence synthesis and research priorities

The strongest evidence is the concordance of molecularly confirmed human cases, patient-fibroblast biochemistry and dermal electron microscopy. Together these establish a causal sequence from COL1A1/COL1A2 exon-6 loss to retained N-propeptide, abnormal fibrillogenesis and systemic connective-tissue laxity. (giunta2008thearthrochalasiatype pages 2-3, giunta2008thearthrochalasiatype pages 1-2, malfait2020theehlers–danlossyndromes pages 6-7)

The most important knowledge gaps are reliable prevalence, prospective natural history, variant-level penetrance and expressivity, validated quality-of-life data, aEDS-specific cardiac/vascular risk, pregnancy outcomes, orthopedic-treatment comparisons, molecular profiling, exact animal models and disease-modifying therapy. The 2024 orthopedic review reinforces the expert view that subtype-confirmed multicenter registries and standardized outcomes are prerequisites for evidence-based surgical algorithms. (schubart2024outcomesoforthopaedic pages 15-16, schubart2024outcomesoforthopaedic pages 1-2)

Key references

1. Malfait F, et al. The 2017 international classification of the Ehlers–Danlos syndromes. Am J Med Genet C. Published March 2017. PMID: 28306229. https://doi.org/10.1002/ajmg.c.31552. (malfait2017the2017international pages 12-13)
2. Martín-Martín M, et al. Ehlers–Danlos Syndrome Type Arthrochalasia: A Systematic Review. Int J Environ Res Public Health. Published 7 February 2022;19:1870. https://doi.org/10.3390/ijerph19031870. (martinmartin2022ehlers–danlossyndrometype pages 7-8, martinmartin2022ehlers–danlossyndrometype pages 1-2)
3. Giunta C, et al. The arthrochalasia type of Ehlers–Danlos syndrome (EDS VIIA and VIIB): the diagnostic value of collagen fibril ultrastructure. Am J Med Genet A. Published April 2008;146A:1341–1346. PMID: 18409203. https://doi.org/10.1002/ajmg.a.32213. (giunta2008thearthrochalasiatype pages 2-3, giunta2008thearthrochalasiatype pages 1-2)
4. Brady AF, et al. The Ehlers–Danlos syndromes, rare types. Am J Med Genet C. Published March 2017;175:115–170. https://doi.org/10.1002/ajmg.c.31550. (brady2017theehlers–danlossyndromes pages 8-9)
5. Malfait F, et al. The Ehlers–Danlos syndromes. Nature Reviews Disease Primers. Published July 2020;6. https://doi.org/10.1038/s41572-020-0194-9. (malfait2020theehlers–danlossyndromes pages 6-7)
6. D’Hondt S, Van Damme T, Malfait F. Vascular phenotypes in nonvascular subtypes of the Ehlers-Danlos syndrome: a systematic review. Genetics in Medicine. Published June 2018. https://doi.org/10.1038/gim.2017.138. (dhondt2018vascularphenotypesin pages 3-4, dhondt2018vascularphenotypesin pages 1-2)
7. Schubart JR, et al. Outcomes of orthopaedic surgery in Ehlers-Danlos syndromes: a scoping review. BMC Musculoskeletal Disorders. Published October 2024;25. https://doi.org/10.1186/s12891-024-07937-6. (schubart2024outcomesoforthopaedic pages 15-16, schubart2024outcomesoforthopaedic pages 1-2)
8. Yonko EA, et al. Orthopedic considerations and surgical outcomes in Ehlers–Danlos syndromes. Am J Med Genet C. Published November 2021;187:458–465. https://doi.org/10.1002/ajmg.c.31958. (yonko2021orthopedicconsiderationsand pages 1-1, yonko2021orthopedicconsiderationsand pages 6-6)

References

1. (martinmartin2022ehlers–danlossyndrometype pages 7-8): Marta Martín-Martín, Jonathan Cortés-Martín, Maria Isabel Tovar-Gálvez, Juan Carlos Sánchez-García, Lourdes Díaz-Rodríguez, and Raquel Rodríguez-Blanque. Ehlers–danlos syndrome type arthrochalasia: a systematic review. Feb 2022. URL: https://doi.org/10.3390/ijerph19031870, doi:10.3390/ijerph19031870. This article has 18 citations.

2. (martinmartin2022ehlers–danlossyndrometype pages 1-2): Marta Martín-Martín, Jonathan Cortés-Martín, Maria Isabel Tovar-Gálvez, Juan Carlos Sánchez-García, Lourdes Díaz-Rodríguez, and Raquel Rodríguez-Blanque. Ehlers–danlos syndrome type arthrochalasia: a systematic review. Feb 2022. URL: https://doi.org/10.3390/ijerph19031870, doi:10.3390/ijerph19031870. This article has 18 citations.

3. (schubart2024outcomesoforthopaedic pages 1-2): Jane R. Schubart, Susan E. Mills, Scott A. Rodeo, and Clair A. Francomano. Outcomes of orthopaedic surgery in ehlers-danlos syndromes: a scoping review. BMC Musculoskeletal Disorders, Oct 2024. URL: https://doi.org/10.1186/s12891-024-07937-6, doi:10.1186/s12891-024-07937-6. This article has 14 citations and is from a peer-reviewed journal.

4. (malfait2017the2017international pages 12-13): Fransiska Malfait, Clair Francomano, Peter Byers, John Belmont, Britta Berglund, James Black, Lara Bloom, Jessica M. Bowen, Angela F. Brady, Nigel P. Burrows, Marco Castori, Helen Cohen, Marina Colombi, Serwet Demirdas, Julie De Backer, Anne De Paepe, Sylvie Fournel‐Gigleux, Michael Frank, Neeti Ghali, Cecilia Giunta, Rodney Grahame, Alan Hakim, Xavier Jeunemaitre, Diana Johnson, Birgit Juul‐Kristensen, Ines Kapferer‐Seebacher, Hanadi Kazkaz, Tomoki Kosho, Mark E. Lavallee, Howard Levy, Roberto Mendoza‐Londono, Melanie Pepin, F. Michael Pope, Eyal Reinstein, Leema Robert, Marianne Rohrbach, Lynn Sanders, Glenda J. Sobey, Tim Van Damme, Anthony Vandersteen, Caroline van Mourik, Nicol Voermans, Nigel Wheeldon, Johannes Zschocke, and Brad Tinkle. The 2017 international classification of the ehlers–danlos syndromes. American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 175:26-8, Mar 2017. URL: https://doi.org/10.1002/ajmg.c.31552, doi:10.1002/ajmg.c.31552. This article has 2455 citations.

5. (wenstrup2002prevalenceofaortic pages 1-2): Richard J. Wenstrup, Richard A. Meyer, Jennifer S. Lyle, Leah Hoechstetter, Peter S. Rose, Howard P. Levy, and Claire A. Francomano. Prevalence of aortic root dilation in the ehlers-danlos syndrome. Genetics in Medicine, 4:112-117, May 2002. URL: https://doi.org/10.1097/00125817-200205000-00003, doi:10.1097/00125817-200205000-00003. This article has 164 citations and is from a highest quality peer-reviewed journal.

6. (OpenTargets Search: arthrochalasia Ehlers-Danlos syndrome-COL1A1,COL1A2): Open Targets Query (arthrochalasia Ehlers-Danlos syndrome-COL1A1,COL1A2, 2 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.

7. (giunta2008thearthrochalasiatype pages 1-2): Cecilia Giunta, Céline Chambaz, Marina Pedemonte, Sara Scapolan, and Beat Steinmann. The arthrochalasia type of ehlers–danlos syndrome (eds viia and viib): the diagnostic value of collagen fibril ultrastructure. American Journal of Medical Genetics Part A, 146A(10):1341-1346, Apr 2008. URL: https://doi.org/10.1002/ajmg.a.32213, doi:10.1002/ajmg.a.32213. This article has 46 citations.

8. (giunta2008thearthrochalasiatype pages 2-3): Cecilia Giunta, Céline Chambaz, Marina Pedemonte, Sara Scapolan, and Beat Steinmann. The arthrochalasia type of ehlers–danlos syndrome (eds viia and viib): the diagnostic value of collagen fibril ultrastructure. American Journal of Medical Genetics Part A, 146A(10):1341-1346, Apr 2008. URL: https://doi.org/10.1002/ajmg.a.32213, doi:10.1002/ajmg.a.32213. This article has 46 citations.

9. (malfait2020theehlers–danlossyndromes pages 6-7): Fransiska Malfait, Marco Castori, Clair A. Francomano, Cecilia Giunta, Tomoki Kosho, and Peter H. Byers. The ehlers–danlos syndromes. Nature Reviews Disease Primers, 6:1-25, Jul 2020. URL: https://doi.org/10.1038/s41572-020-0194-9, doi:10.1038/s41572-020-0194-9. This article has 409 citations.

10. (brady2017theehlers–danlossyndromes pages 8-9): Angela F. Brady, Serwet Demirdas, Sylvie Fournel‐Gigleux, Neeti Ghali, Cecilia Giunta, Ines Kapferer‐Seebacher, Tomoki Kosho, Roberto Mendoza‐Londono, Michael F. Pope, Marianne Rohrbach, Tim Van Damme, Anthony Vandersteen, Caroline van Mourik, Nicol Voermans, Johannes Zschocke, and Fransiska Malfait. The ehlers–danlos syndromes, rare types. American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 175:115-70, Mar 2017. URL: https://doi.org/10.1002/ajmg.c.31550, doi:10.1002/ajmg.c.31550. This article has 318 citations.

11. (martinmartin2022ehlers–danlossyndrometype pages 5-7): Marta Martín-Martín, Jonathan Cortés-Martín, Maria Isabel Tovar-Gálvez, Juan Carlos Sánchez-García, Lourdes Díaz-Rodríguez, and Raquel Rodríguez-Blanque. Ehlers–danlos syndrome type arthrochalasia: a systematic review. Feb 2022. URL: https://doi.org/10.3390/ijerph19031870, doi:10.3390/ijerph19031870. This article has 18 citations.

12. (dhondt2018vascularphenotypesin pages 3-4): Sanne D'hondt, Tim Van Damme, and Fransiska Malfait. Vascular phenotypes in nonvascular subtypes of the ehlers-danlos syndrome: a systematic review. Jun 2018. URL: https://doi.org/10.1038/gim.2017.138, doi:10.1038/gim.2017.138. This article has 107 citations and is from a highest quality peer-reviewed journal.

13. (martinmartin2022ehlers–danlossyndrometype pages 4-5): Marta Martín-Martín, Jonathan Cortés-Martín, Maria Isabel Tovar-Gálvez, Juan Carlos Sánchez-García, Lourdes Díaz-Rodríguez, and Raquel Rodríguez-Blanque. Ehlers–danlos syndrome type arthrochalasia: a systematic review. Feb 2022. URL: https://doi.org/10.3390/ijerph19031870, doi:10.3390/ijerph19031870. This article has 18 citations.

14. (schubart2024outcomesoforthopaedic pages 15-16): Jane R. Schubart, Susan E. Mills, Scott A. Rodeo, and Clair A. Francomano. Outcomes of orthopaedic surgery in ehlers-danlos syndromes: a scoping review. BMC Musculoskeletal Disorders, Oct 2024. URL: https://doi.org/10.1186/s12891-024-07937-6, doi:10.1186/s12891-024-07937-6. This article has 14 citations and is from a peer-reviewed journal.

15. (islam2021ehlersdanlossyndromeimmunologic pages 31-33): Mareesa Islam, Christopher Chang, and M. Eric Gershwin. Ehlers-danlos syndrome: immunologic contrasts and connective tissue comparisons. Jan 2021. URL: https://doi.org/10.1016/j.jtauto.2020.100077, doi:10.1016/j.jtauto.2020.100077. This article has 40 citations and is from a peer-reviewed journal.

16. (martinmartin2022ehlers–danlossyndrometype pages 2-4): Marta Martín-Martín, Jonathan Cortés-Martín, Maria Isabel Tovar-Gálvez, Juan Carlos Sánchez-García, Lourdes Díaz-Rodríguez, and Raquel Rodríguez-Blanque. Ehlers–danlos syndrome type arthrochalasia: a systematic review. Feb 2022. URL: https://doi.org/10.3390/ijerph19031870, doi:10.3390/ijerph19031870. This article has 18 citations.

17. (yonko2021orthopedicconsiderationsand pages 2-3): Elizabeth A. Yonko, Holly M. LoTurco, Erin M. Carter, and Cathleen L. Raggio. Orthopedic considerations and surgical outcomes in ehlers–danlos syndromes. American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 187:458-465, Nov 2021. URL: https://doi.org/10.1002/ajmg.c.31958, doi:10.1002/ajmg.c.31958. This article has 36 citations.

18. (lucente2024chiropractictreatmentof pages 1-2): M Lucente and KS Walden. Chiropractic treatment of a patient with ehlers-danlos syndrome: a case report. Unknown journal, 2024.

19. (lamande2020geneticdisordersof pages 1-2): Shireen R. Lamandé and John F. Bateman. Genetic disorders of the extracellular matrix. Anatomical Record (Hoboken, N.j. : 2007), 303:1527-1542, Mar 2020. URL: https://doi.org/10.1002/ar.24086, doi:10.1002/ar.24086. This article has 129 citations.

20. (yonko2021orthopedicconsiderationsand pages 1-1): Elizabeth A. Yonko, Holly M. LoTurco, Erin M. Carter, and Cathleen L. Raggio. Orthopedic considerations and surgical outcomes in ehlers–danlos syndromes. American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 187:458-465, Nov 2021. URL: https://doi.org/10.1002/ajmg.c.31958, doi:10.1002/ajmg.c.31958. This article has 36 citations.

21. (yonko2021orthopedicconsiderationsand pages 6-6): Elizabeth A. Yonko, Holly M. LoTurco, Erin M. Carter, and Cathleen L. Raggio. Orthopedic considerations and surgical outcomes in ehlers–danlos syndromes. American Journal of Medical Genetics Part C: Seminars in Medical Genetics, 187:458-465, Nov 2021. URL: https://doi.org/10.1002/ajmg.c.31958, doi:10.1002/ajmg.c.31958. This article has 36 citations.

22. (dhondt2018vascularphenotypesin pages 1-2): Sanne D'hondt, Tim Van Damme, and Fransiska Malfait. Vascular phenotypes in nonvascular subtypes of the ehlers-danlos syndrome: a systematic review. Jun 2018. URL: https://doi.org/10.1038/gim.2017.138, doi:10.1038/gim.2017.138. This article has 107 citations and is from a highest quality peer-reviewed journal.

Artifacts

• Edison artifact artifact-00

Reference Validation

Checked with linkml-reference-validator 0.2.1.

All extracted references resolved successfully.

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

• MONDO:0007525 (5 mentions) - the report calls it "if available"; MONDO calls it Ehlers-Danlos syndrome, arthrochalasia type

Prefixes with no resolver

Terms carrying these prefixes were not checked either way, because no configured ontology covers them. An unrecognised prefix may name an ontology this run could not reach as easily as one that does not exist, so nothing here is evidence of fabrication: Gene, Taxon.