Spondylometaphyseal dysplasia, east-African type: a new form of early, severe SMD with rounded vertebrae.

Spondylometaphyseal dysplasias (SMD) are a heterogeneous group of bone dysplasias characterized by vertebral and metaphyseal changes of various severities. We report two unrelated patients of east African origin with a skeletal disorder consisting of 1) severe metaphyseal dysplasia of early onset, sparing hand bones, with bracket-shaped metaphyses; 2) dysplastic pelvis with irregular iliac rim; and 3) oval-shaped vertebral bodies. Contrasting with most types of SMD, the spinal dysplasia is limited to mild changes in the vertebral body shape that tend to soften with time, whereas the iliac rims have a striking lacy appearance. Except for the most common types (Kozlowski type and Schmidt type), most of the literature on SMD deals with single case reports, without longitudinal data, for which molecular definition is still lacking and classification remains unclear. These two patients could belongs to the A4 group in the classification of Maroteaux and Spranger [1991: Pediatr Radiol 2l:293-297], and illustrate the difficulties of a clinical classification of SMD.