| Feature | Suggested HPO term | Notes (age of onset / progression) | Frequency (if known) | Citations |
|---|---|---|---|---|
| Joint pain / arthralgia | Arthralgia (HP:0002829) | Often first recognized in early childhood; progressive and associated with later degenerative joint disease/early osteoarthritis | 17/25 (68%) in Daşar 2025 cohort | (pqac-00000000, pqac-00000006) |
| Short stature / mildly reduced adult height | Short stature (HP:0004322) | Frequently mild or absent at birth; may become apparent in childhood; adult height often near-normal or mildly reduced | 9/25 (36%) in Daşar 2025 cohort | (pqac-00000000, pqac-00000003, pqac-00000006) |
| Walking difficulty / abnormal gait | Abnormality of gait (HP:0001288) | Early-childhood presentation; often linked to hip/knee pain, deformity, or myopathy-like findings; may progress with joint degeneration | Not quantified in retrieved cohort text | (pqac-00000000, pqac-00000003, pqac-00000032) |
| Waddling gait | Waddling gait (HP:0002515) | Reported in childhood and adolescence; reflects proximal lower-limb weakness/deformity and hip disease | Not quantified in retrieved cohort text | (pqac-00000002, pqac-00000035) |
| Myopathy-like features / muscle weakness | Proximal muscle weakness (HP:0003701) | May be an early presenting complaint and can mimic neuromuscular disease; contributes to diagnostic delay | Not quantified in retrieved cohort text | (pqac-00000003, pqac-00000006, pqac-00000032) |
| Hypotonia | Hypotonia (HP:0001252) | Can be present in infancy/early childhood; associated with delayed walking and joint laxity in some cases | Not quantified in retrieved cohort text | (pqac-00000005, pqac-00000034) |
| Epiphyseal irregularity / generalized epiphyseal dysplasia | Irregular epiphyses (HP:0003090) | Core radiographic hallmark; detected in childhood; involves hips and knees prominently and persists/progresses with growth | Not quantified in retrieved cohort text | (pqac-00000000, pqac-00000002, pqac-00000035, pqac-00000036) |
| Flattened epiphyses | Flattened epiphysis (HP:0003100) | Seen on childhood radiographs; small, flat, irregular epiphyses are classic MED findings | Not quantified in retrieved cohort text | (pqac-00000000, pqac-00000035, pqac-00000036) |
| Delayed epiphyseal/carpal ossification | Delayed ossification of epiphyses (HP:0003093) | Childhood radiographic feature; may include delayed carpal ossification and altered bone age | Not quantified in retrieved cohort text | (pqac-00000002, pqac-00000005, pqac-00000032, pqac-00000035) |
| Acetabular dysplasia | Acetabular dysplasia (HP:0003272) | Common hip manifestation; contributes to pain, gait abnormality, and later hip osteoarthritis; may prompt corrective osteotomy | Not quantified in retrieved cohort text | (pqac-00000000, pqac-00000003, pqac-00000031, pqac-00000035) |
| Coxa vara | Coxa vara (HP:0002812) | Can be recognized in childhood; contributes to gait disturbance and hip dysfunction; may progress | Not quantified in retrieved cohort text | (pqac-00000000, pqac-00000003, pqac-00000032, pqac-00000035) |
| Genu valgum | Genu valgum (HP:0002857) | Childhood lower-limb deformity; may require guided growth or osteotomy | Present in surgical subgroup; exact cohort-wide frequency not reported | (pqac-00000006, pqac-00000011, pqac-00000031) |
| Genu varum | Genu varum (HP:0002974) | Childhood deformity; may coexist with other lower-limb malalignment and progress with growth | Not quantified in retrieved cohort text | (pqac-00000003, pqac-00000035) |
| Early-onset osteoarthritis / degenerative joint disease | Osteoarthritis (HP:0002758) | Progressive complication, often emerging in adolescence or early adulthood and affecting large weight-bearing joints; may lead to arthroplasty | Not quantified in Daşar cohort; MED patients can require joint replacement relatively young | (pqac-00000000, pqac-00000004, pqac-00000027) |
| Orthopedic surgery requirement | Arthroplasty / corrective osteotomy-related phenotype annotation not directly represented by one HPO term; consider Abnormality of the musculoskeletal system (HP:0033127) plus procedure ontology outside HPO | Marker of severity; reflects progressive deformity/osteoarthritis requiring intervention | 7/25 (28%) in Daşar 2025 cohort | (pqac-00000000, pqac-00000006, pqac-00000011) |
| Double-layered / bipartite patella | Bipartite patella (HP:0006485) | Relatively characteristic of SLC26A2-related MED; detected radiographically, often in childhood | ~60% of SLC26A2-related MED in one source | (pqac-00000001, pqac-00000021, pqac-00000031, pqac-00000036) |
| Glacier sign / glacier crevice sign | Radiographic sign; no exact HPO term identified in retrieved evidence, suggested parent term Abnormality of the knee joint (HP:0002815) | Knee imaging sign reported in MED cohorts, particularly useful diagnostically in childhood | Not quantified in retrieved cohort text | (pqac-00000003, pqac-00000032, pqac-00000036) |
| Osteochondritis dissecans | Osteochondritis dissecans (HP:0002759) | Not a classic universal MED feature; reported as a major/expanding manifestation in some COMP- and COL9A2-related cases; may present in adolescence/young adulthood | Rare; no cohort frequency in retrieved MED cohort | (pqac-00000004, pqac-00000024) |
| Male sex in reported cohort | Phenotypic sex not an HPO disease feature | Cohort descriptor rather than phenotype; included for knowledge-base completeness | 16/25 (64%) male in Daşar 2025 cohort | (pqac-00000000, pqac-00000006) |


*Table: This table maps major clinical and radiographic features of multiple epiphyseal dysplasia to suggested HPO terms, with onset/progression notes and available cohort frequencies. It is useful for disease knowledge-base curation and phenotype annotation.*