Osteocraniostenosis-hypomineralized skull with gracile long bones and splenic hypoplasia. Four new cases with distinctive chondro-osseous morphology.

Osteocraniostenosis is a severe skeletal dysplasia characterized by a hypomineralized skull that has been previously described as kleeblattschädel (cloverleaf skull) and overtubulated long bones. Dysmorphic facial features include a short nose, short philtrum, and a small, inverted V-shaped mouth. Splenic a/hypoplasia is a constant finding. We report four infants (two unrelated and two siblings) with osteocraniostenosis and describe the clinical, radiographic and chondro-osseous morphology findings. The two siblings lack the moderate long-bone shortening that is typically seen. The skull configuration is likely caused by severely hypoplastic cranial bones (parietal) rather than true craniosynostosis, making the term "osteocraniostenosis" misleading. Histological examination of bone in all cases showed an abnormal growth plate with short irregular columns. The resting cartilage showed pleomorphic chondrocytes with increased cellularity and unique pseudocolumn formation. There are some radiographic and chondro-osseous morphologic similarities between osteocraniostenosis and severe Hallermann-Streiff syndrome (HSS), suggesting the two disorders may be pathogenetically related.

Hand involvement in Schmid metaphyseal chondrodysplasia.

Schmid metaphyseal chondrodysplasia (Schmid MCD, MIM 156500) is caused by mutations in the COL10A1 gene and is clinically characterized by short stature, bowed legs, and a waddling gait. Radiographic findings include anterior cupping, sclerosis and splaying of the ribs, diffuse metaphyseal flaring, and irregularity that is most pronounced at the knees, coxa vara, and femoral bowing. We reviewed the radiographs of Schmid MCD patients at the International Skeletal Dysplasia Registry in Los Angeles for evidence of hand involvement. We found hand involvement in 47% (7/15) of cases included in our analysis. These changes were subtle and consisted of shortening of the tubular bones and metaphyseal cupping of the proximal phalanges and metacarpals. Mild hand involvement is a common feature of Schmid MCD.

Occipital projections in the skeletal dysplasias.

Occipital projections of the cranium have been reported in a number of skeletal dysplasias and syndromes. We observed two cases of atelosteogenesis type I with a bony occipital projection. This finding has neither been noted nor reported in any form of atelosteogenesis. This led us to search the International Skeletal Dysplasia Registry for occipital projections, and we found them in four other syndromes in which they had not been reported. Thus occipital spurs are a non-diagnostic feature that can be found in at least ten distinct disorders as well as a normal variant.

Pacman dysplasia: a lethal skeletal dysplasia with variable radiographic features.

BACKGROUND: Punctate or stippled cartilaginous calcifications are associated with many conditions, including chromosomal, infectious, endocrine, and teratogenic etiologies. Some of these conditions are clinically mild, while others are lethal. Accurate diagnosis can prove instrumental in clinical management and in genetic counseling. OBJECTIVE: To describe the diagnostic radiographic features seen in Pacman dysplasia, a distinct autosomal recessive, lethal skeletal dysplasia. MATERIALS AND METHODS: We present the fourth reported case of Pacman dysplasia and compare the findings seen in our patient with the three previously described patients. RESULTS: Invariable and variable radiographic findings were seen in all four cases of histologically proven Pacman dysplasia. CONCLUSION: Pacman dysplasia presents both constant and variable diagnostic radiographic features.