99 Spondyloepimetaphyseal Dysplasia, Strudwick Type
SEMD Strudwick type, SMED type I, dappled metaphysis syndrome
Severe short trunk-short limb dwarfism, normal-sized hands and feet, marked pectus carinatum, dappled metaphyses
Frequency: Rare (fewer than 50 published cases).
Genetics
Autosomal dominant (OMIM 184250); caused by mutation of COL2A1, mapped to chromosome 12q13.11-q13.2. May be the same as severe spondy- loepiphyseal dysplasia congenita (vide infra).
Clinical Features
• Severe short trunk-short limb dwarfism,short neck
• Normal face, midface hemangioma
• Retinal detachment, myopia
• Cleft palate
• Chest deformity, pectus carinatum
• Lumbar lordosis, moderate kyphoscoliosis (cord compression in adulthood)
• Inguinal hernia
• Dislocated hips
• Genu valgum
• Clubfoot, pes planus Differential Diagnosis
• Spondylometaphyseal dysplasia, Schmidt type
• Morquio syndrome
Radiographic Features:
1. At birth and During Infancy
(indistinguishable from SED congenita) Generalized Skeletal Abnormalities
• Marked delay in epiphyseal ossification (proximal femurs and pubic bones) Limbs
• Disproportionately short limbs, club-shaped proximal femurs Spine
• Platyspondyly
• Defective ossification of the first cervical verte- brae and sacrum
Radiographic Features:
2. Childhood Extremities
• Metaphyseal irregularity, sclerotic mottling, dap- pling (proximal humerus/femur and distal ulna/
radius, ulna more severely affected than radius, fibula than tibia) (metaphyseal changes permit differentiation from SED congenita)
• Normal hands and feet, delayed ossification of carpals
Pelvis
• Delay in ossification of pubic bones and proximal femurs
• Coxa vara
• Narrow sciatic notches
• Flat acetabular roofs with medial and lateral beaking
Spine
• Platyspondyly
• Pear-shaped vertebrae (dorsal wedging)
• Odontoid hypoplasia, atlanto-axial instability
• Lumbar hyperlordosis, scoliosis Chest
• Anteriorly splayed, slightly short ribs
• Pectus carinatum
Bibliography
Anderson CE, Sillence DO, Lachman RS, Toomey K, Bull M, Dorst JP, Rimoin DL. Spondylometaepiphyseal dysplasia, Strudwick type. Am J Med Genet 1982; 13: 243–56 Kaitila I, Korkko J, Marttinen E, Ala-Kokko L. Phenotypic ex-
pressions of a Gly 154Arg mutation in type II collagen in two unrelated patients with spondyloepimetaphyseal dys- plasia (SEMD). Am J Med Genet 1996; 63: 111–22
Kozlowski K, Beemer FA Bens G, Dijkstra PF, Iannaccone G, Emons D, Lopez-Ruiz P, Masel J, van Nieuwenhuizen O, Rodriguez-Barrionuevo C. Spondylo-metaphyseal dyspla- sia: report of 7 cases and essay of classification. In: Pa- padatos CJ, Bartsocas CS (eds.) Skeletal dysplasias. Alan R.
Liss, New York, 1982, pp. 89–101
LaQuesne GW, Kozlowski K. Spondylometaphyseal dysplasia.
Br J Radiol 1973; 46: 685–91
Maroteaux P, Spranger J. The spondylometaphyseal dysplasias.
A tentative classification. Pediatr Radiol 1991; 21: 293–7 Shebib SM, Chudley AE, Reed MH. Spondylometepiphyseal
dysplasia congenita, Strudwick type. Pediatr Radiol 1991;
21: 298–300 Spondyloepimetaphyseal Dysplasia, Strudwick Type
884
Spondyloepimetaphyseal Dysplasia, Strudwick Type 885
S
Fig. 99.1 a, b. Patient 1, at 30 months of age. Note rhizomelic short-limb dwarfism, normal hands, normal craniofacial features, bell-shaped thorax, pectus carinatum, protruding abdomen, and lumbar hyperlordosis.
(Reprinted, with permission, from Shebib et al. 1991)
a b
Fig. 99.2 a, b. Patient 1, at 4 years and 6 months of age. Odontoid hypoplasia and atlanto-axial instability are apparent. (Reprint- ed, with permission, from Shebib et al. 1991)
a b
Spondyloepimetaphyseal Dysplasia, Strudwick Type 886
Fig. 99.3. Patient 1, at 2 years and 6 months of age. Proximal femoral epiphyses are not ossified, and pubic bones are poorly ossified.
Acetabular roofs are flat and mal- formed, with medial and lateral beaking. (Reprinted, with permis- sion, from Shebib et al. 1991)
Fig. 99.4. aPatient 1, at age 10 months. Note absence of epi- physeal ossification at the hip and knee level, and metaphyseal abnormalities most prominent in proximal and distal femur.
bPatient 1, at 2 years and 6 months of age. Severe metaphyseal irregularities, including sclerotic mottling and cupping, have developed. (Reprinted, with permission, from Shebib et al. 1991)
a b
Fig. 99.5 a, b. Patient 1, at the age of a 10 months and b 2 years and 6 months. Note striking metaphyseal changes that have developed during early childhood. (Reprinted, with permis- sion, from Shebib et al. 1991)
a b
