Ischiospinal dysostosis with rib gaps and nephroblastomatosis.

Rib gaps, vertebral ossification defects, hypoplastic ischial bones and large kidneys were present in a newborn. A renal biopsy showed nephroblastomatosis . The observation links two recently described conditions - 'ischiospinal dysostosis' and 'a new syndrome comprising vertebral anomalies and multicystic kidneys' - and shows that nephroblastomatosis may be a manifestation of ischiospinal dysostosis. Ischiospinal dysostosis with nephroblastomatosis is one of a group of disorders characterized by developmental defects of the axial skeleton. It must be added to the conditions predisposing to Wilms tumor formation.