schema: eds-research/corpus/v1
category:
  id: diagnosis-and-classification
  label: Diagnosis and classification
  description: "How EDS is diagnosed: the Beighton score, the three-part 2017 hEDS criteria, genetic confirmation of the other types, and why older studies used different criteria."
  order: 20
records:
  - id: class-heds-2017-criteria
    kind: finding
    title: The 2017 hEDS criteria require hypermobility, systemic manifestations, and exclusion
    description: The 2017 hEDS criteria require joint hypermobility, two or more further features, and exclusion of other conditions. No genetic test confirms hEDS.
    summary: hEDS diagnosis under the 2017 International Classification requires (1) generalized joint hypermobility by Beighton score, (2) two or more of systemic manifestations, positive family history, or musculoskeletal complications, and (3) exclusion of other connective-tissue disorders. Unlike every other subtype, hEDS has no molecular confirmation test.
    date: "2017-03"
    date_precision: month
    subtypes: [heds, hsd]
    status: established
    criteria_era: international-2017
    evidence:
      - stratum: clinical
        tier: consensus-statement
        source_ids: [source-36ad1cab53c4cea4f4b4]
      - stratum: community
        tier: patient-org-synthesis
        source_ids: [source-c55aca51ea775bf6d160, source-1f24758814c322b4d394]
        note: The society's diagnostic checklist restates the same three-part structure.
    corroboration: single-origin
    reviewed_at: "2026-09-16"
    tags: [diagnosis, criteria]
  - id: class-molecular-confirmation-required
    kind: finding
    title: Twelve subtypes require molecular confirmation; hEDS remains clinical
    summary: "Under the 2017 classification, definitive diagnosis of every subtype except hEDS relies on identifying a causative genetic variant. This asymmetry is the central classification problem: the most common type is the only one without a confirmatory test."
    date: "2017-03"
    date_precision: month
    subtypes: [all-eds]
    status: established
    criteria_era: international-2017
    evidence:
      - stratum: clinical
        tier: consensus-statement
        source_ids: [source-36ad1cab53c4cea4f4b4]
    reviewed_at: "2026-09-16"
    tags: [diagnosis, genetics]
  - id: class-hsd-residual-category
    kind: finding
    title: HSD was created as the residual category beside hEDS
    summary: The 2017 framework (Castori et al.) separated symptomatic joint hypermobility into hEDS when the strict criteria are met and HSD when they are not. The boundary is contested. The criteria were designed to define a more uniform group for research, not to declare HSD benign, and the hEDS/HSD criteria review study is ongoing.
    date: "2017-03"
    date_precision: month
    subtypes: [hsd, heds]
    status: established
    criteria_era: international-2017
    evidence:
      - stratum: clinical
        tier: consensus-statement
        source_ids: [source-d7dec285eaee780f18a3]
      - stratum: clinical
        tier: cross-sectional-study
        source_ids: [source-de164233cddfefc4105a]
        note: The 2025 German survey groups hEDS and HSD together because their features overlap.
    reviewed_at: "2026-09-16"
    tags: [diagnosis, hsd]
  - id: class-criteria-era-drift
    kind: finding
    title: Criteria-era drift makes old and new EDS literature non-equivalent
    summary: Villefranche-era “EDS type III” cohorts (1997–2017) do not map cleanly onto 2017 hEDS. The 2017 criteria are stricter, and some people who met the older hypermobility-type criteria would now be diagnosed with HSD. Studies that mix eras need to be read with that in mind.
    subtypes: [all-eds]
    status: established
    criteria_era: era-independent
    evidence:
      - stratum: clinical
        tier: consensus-statement
        source_ids: [source-36ad1cab53c4cea4f4b4, source-a0e3bc5bd3a0b3545cf8]
    reviewed_at: "2026-09-16"
    tags: [methodology, criteria]
  - id: dx-heds-remains-clinical
    kind: finding
    title: hEDS diagnosis remains clinical despite the KLK15 finding
    description: The Ehlers-Danlos Society says KLK genes are not on EDS genetic testing panels and hEDS remains a clinical diagnosis despite the KLK15 finding.
    summary: The Ehlers-Danlos Society says kallikrein (KLK) genes are not on EDS genetic testing panels and that hEDS remains a clinical diagnosis, and that further studies, including the HEDGE study, are needed to replicate the KLK15 finding. The KLK15 authors say their study does not propose a diagnostic framework and that the absence of KLK15 variants should not rule out a clinical diagnosis.
    date: "2025-08"
    date_precision: month
    subtypes: [heds]
    status: established
    criteria_era: international-2017
    evidence:
      - stratum: community
        tier: patient-org-synthesis
        source_ids: [source-bb268c000069896e8023]
      - stratum: clinical
        tier: consensus-statement
        source_ids: [source-36ad1cab53c4cea4f4b4]
      - stratum: clinical
        tier: mechanistic-study
        source_ids: [source-ee867f99ac8808a4ef80]
      - stratum: registry
        tier: registry-report
        source_ids: [source-3440a2b9d5d99c580d3a]
    corroboration: convergent
    reviewed_at: "2026-09-16"
    reassess_by: "2026-12-16"
    tags: [diagnosis, genetics]