Figure 2.

Radiographic Abnormalities in the Individuals Affected with SMMD

(A–C) Radiographs taken in proband IV.3 at the age of 10 months.

(A) The vertebral bodies are incompletely ossified and show sagittal clefts. The pedicles are well ossified in the lower thoracic and upper lumbar region. The ribs originate remotely from the vertebral column.

(B) The pelvis is abnormal with short iliac wings, widened triradiate cartilages, and absent ossification of the pubic bones. Remarkable are the round femoral epiphyses separated by a broad cartilage zone (growth plate) from their metaphyses.

(C) The knee and ankle epiphyses are also rounded and ballooned and located remotely from the metaphyses. The tubular bones are poorly modeled.

(D) Babygram of the affected sib of proband IV.3 taken at 19 weeks' gestational age showing complete absence of vertebral ossification.

(E–G) Radiographs taken in the third proband at the age of 11 years.

(E) Defective ossification of the cervical spine that mostly involves the vertebral bodies with preservation of the pedicles and neural arches.

(F) The iliac wings are tall and narrow. The pubic bones are not yet ossified. Severe coxa vara is present with metaphyseal irregularities at the acetabular roofs and femoral necks that show ossification defects.

(G) Multiple pseudoepiphyses are present, mostly visible in the metacarpals and proximal phalanges. All epiphyses are large for age. Metaphyseal irregularities are also present and in some instances resemble enchondromata, especially those at the distal radius, distal part of second and third metacarpals, and proximal part of the first to fourth proximal phalanges. The second metacarpal is very tall.

(H and I) Radiographs taken in proband IV.8 at the age of 18 years.

(H) Only few hand abnormalities are visible at this age. Pseudoepiphyses are still present in the thumb. Not all growth plates are closed. Note the tall first metacarpal and proximal phalanx and still enlarged distal epiphyses of radius and ulna.

(I) The pelvis shows hypoplastic iliac wings, severe coxa vara with dysplastic femoral heads, and incomplete ossification of the pubic rami.