Spondyloepiphyseal or spondyloepimetaphyseal dysplasias

**Definition:** Spondyloepiphyseal dysplasias (SED) are a heterogeneous group of congenital chondrodysplasias that specifically affect epiphyses and vertebrae. Their most frequent form is characterised by small neonatal size of ovid vertebrae and overall late growth of bones, more marked in the femoral heads, with a slightly irregular metaphyseal limit. Other clinical forms have been described, some of which were dominant and more or less severe with metaphyseal lesions, while others were recessive and included nephrotic syndrome, lymphopenia, and immune disorders (immune bone dysplasia).