Ror2 Knockout Mouse as a Model for the Developmental Pathology of Autosomal Recessive Robinow Syndrome

Abstract

Robinow syndrome (RS) is a human dwarfism syndrome characterized by mesomelic limb shortening, vertebral and craniofacial malformations and small external genitals. We have analyzed Ror-/- mice as a model for the developmental pathology of RS. Our results demonstrate that vertebral malformations in Ror2-/- mice are due to reductions in the presomitic mesoderm and defects in somitogenesis. Mesomelic limb shortening in Ror2-/- mice is a consequence of perturbed chondrocyte differentiation. Moreover, we show that the craniofacial phenotype is caused by a midline outgrowth defect. Ror2 expression in the genital tubercle and its reduced size in Ror2-/- mice makes it likely that Ror2 is involved in genital development. In conclusion, our findings suggest that Ror2 is essential at multiple sites during development. The Ror2-/- mouse provides a suitable model that may help to explain many of the underlying developmental malformations in individuals with Robinow syndrome. © 2004 Wiley-Liss, Inc.