Definition:

Diaphanospondylodysostosis (DSD) is a rare, recessively inherited, perinatal lethal skeletal disorder. It is one of a number of spinal dysostoses, which are a heterogeneous group of axial skeletal malformations occurring during blastogenesis with continued evolution after birth. The primary skeletal characteristics of the phenotype include a small chest, abnormal vertebral segmentation, and posterior rib gaps containing incompletely differentiated mesenchymal tissue. The spine is most prominently affected, with diaphanous, that is, translucent vertebrae, due to abnormal vertebral ossification and segmentation. A consistent feature of all described DSD cases are renal findings of dysplasia, nephrogenic rests or nephroblastomatosis, and/or cysts. It has been determined that DSD is due to mutations in the BMPER gene, which encodes the bone morphogenetic protein-binding endothelial cell precursor-derived regulator.