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Spondyloepiphyseal dysplasia (SED) is a group of rare, inherited skeletal dysplasias characterized by abnormal development of the spine (spondylo-) and epiphyses (ends of long bones).
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| Type | Inheritance | Age of Onset | Notes |
|---|---|---|---|
| SED congenita (SEDC) | AD (COL2A1 mutation) | Present at birth | More severe; vertebral and epiphyseal abnormalities |
| SED tarda | XLR (TRAPPC2 mutation) | Late childhood/adolescence | Milder; later diagnosis; joint pain precedes short stature |
| Pseudoachondroplasia | AD | Early childhood | No facial abnormalities; epiphyseal/ metaphyseal involvement |
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Affected children demonstrate disproportionately short‐trunk short stature with a barrel‐shaped chest together with classic radiographic changes in the axial and appendicular skeleton.
The manifestations are not present at birth but appear later in childhood, typically between ages 6 and 10 years.
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| System | Manifestations |
|---|---|
| Stature | Short trunk dwarfism, normal limb length |
| Spine | Kyphoscoliosis, platyspondyly, lumbar lordosis |
| Joints | Early-onset arthritis, hip pain, waddling gait |
| Limbs | Short limbs in some forms, delayed ossification of epiphyses |
| Facial features | Mild flat facies, normal intelligence, no coarse features |
| Eyes & Ears | In SED congenita: myopia, retinal detachment, hearing loss |
(a-d) Spondyloepiphyseal dysplasia tarda. Radiograph of the lumbar spine and hip AP view (a) in an adolescent patient 1 shows degenerative changes of spine with scoliotic deformity and bilateral hip dysplasia in the form of coxa breva, hip subluxation, shallow, and vertical acetabuli. Follow-up radiographs (b) show significant bilateral arthritic changes. Note the superior-lateral diminution of joint space, subchondral sclerosis. Hand radiograph anteroposterior view of an adolescent patient 2 (c) shows carpal bone amalgamation, sclerosis, and irregularities and the clinical deformity (d)
El-Sobky TA, Shawky RM, Sakr HM, Elsayed SM, Elsayed NS, Ragheb SG, Gamal R. A systematized approach to radiographic assessment of commonly seen genetic bone diseases in children: A pictorial review. J Musculoskelet Surg Res 2017;1:25-32
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Presentation at birth with hallmark delayed ossification of epiphyses.
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| Region | Feature | Description |
|---|---|---|
| A. Spine | ‣ | Flattened vertebral bodies |
| Anterior wedging/beaking | May mimic mucopolysaccharidosis but without systemic signs | |
| Kyphoscoliosis | Especially in thoracolumbar spine | |
| B. Epiphyses | Hips | Delayed ossification, flattened femoral heads, dysplastic acetabulum |
| Knees & ankles | Irregular epiphyses, valgus deformities | |
| Shoulders & elbows | Delayed ossification and joint incongruity | |
| C. Pelvis | Iliac wings | Small or hypoplastic |
| Acetabular roof | Dysplastic, flat | |
| Femoral necks | Short and broad | |
| D. Others | Odontoid hypoplasia | Risk of atlantoaxial instability in SED congenita |
| Limb bones | Usually normal in length, mild metaphyseal flaring in some cases |
![Spondyloepiphyseal dysplasia congenita. Lateral radiographs of dorsolumbar spine show platyspondyly (arrow, A) with severely reduced intervertebral disc spaces (arrow, B). Radiograph of pelvis (C) shows small femoral epiphyses (white arrow), horizontal acetabuli (black arrow) and short iliac wings (a). Radiograph of skull (D) shows relatively enlarged calvarium (arrow). Radiographs of lower limbs (E, F) show relatively short femurs and small epiphyses with secondary metaphyseal irregularity (arrow, F).
Panda A, Gamanagatti S, Jana M, Gupta AK. Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias. World J Radiol 2014; 6(10): 808-825 [PMID: 25349664 DOI: 10.4329/wjr.v6.i10.808]](https://prod-files-secure.s3.us-west-2.amazonaws.com/2aa05644-4658-4c26-84d3-64c36b55fb6c/77d08cb6-ef8e-44a1-95e6-aa0c0072956d/WJR-6-808-g001.jpg)
Spondyloepiphyseal dysplasia congenita. Lateral radiographs of dorsolumbar spine show platyspondyly (arrow, A) with severely reduced intervertebral disc spaces (arrow, B). Radiograph of pelvis (C) shows small femoral epiphyses (white arrow), horizontal acetabuli (black arrow) and short iliac wings (a). Radiograph of skull (D) shows relatively enlarged calvarium (arrow). Radiographs of lower limbs (E, F) show relatively short femurs and small epiphyses with secondary metaphyseal irregularity (arrow, F).
Panda A, Gamanagatti S, Jana M, Gupta AK. Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias. World J Radiol 2014; 6(10): 808-825 [PMID: 25349664 DOI: 10.4329/wjr.v6.i10.808]
![Spondyloepiphyseal dysplasia tarda. Lateral radiograph of lumbar spine (A) shows characteristic posterior hump (arrow). Radiograph of pelvis (B) shows bilateral flattened femoral heads, short necks and premature degenerative changes (arrow).
Panda A, Gamanagatti S, Jana M, Gupta AK. Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias. World J Radiol 2014; 6(10): 808-825 [PMID: 25349664 DOI: 10.4329/wjr.v6.i10.808]](https://prod-files-secure.s3.us-west-2.amazonaws.com/2aa05644-4658-4c26-84d3-64c36b55fb6c/15afc482-1294-4dcb-a388-02369e99cf82/WJR-6-808-g002.jpg)
Spondyloepiphyseal dysplasia tarda. Lateral radiograph of lumbar spine (A) shows characteristic posterior hump (arrow). Radiograph of pelvis (B) shows bilateral flattened femoral heads, short necks and premature degenerative changes (arrow).
Panda A, Gamanagatti S, Jana M, Gupta AK. Skeletal dysplasias: A radiographic approach and review of common non-lethal skeletal dysplasias. World J Radiol 2014; 6(10): 808-825 [PMID: 25349664 DOI: 10.4329/wjr.v6.i10.808]
| Condition | Key Differences |
|---|---|
| Achondroplasia | Rhizomelic limb shortening, trident pelvis, normal epiphyses |
| Mucopolysaccharidosis (MPS) | Coarse facies, organomegaly, dysostosis multiplex |
| Pseudoachondroplasia | More metaphyseal involvement, ligamentous laxity, normal face |
| Multiple epiphyseal dysplasia (MED) | No spinal involvement, only epiphyseal changes |
