Craniometric measurements of craniofacial malformations in mice with X-linked, dominant hypophosphatemia (vitamin D-resistant rickets).

Skulls of hemizygous male and heterozygous female C57CL/6J mice affected with X-linked, dominant hypophosphatemia ("Hyp" mutant; C57BL/6J-Hyp)--vitamin D-resistant rickets (VDRR)--were compared grossly and by craniometry with skulls of normal C57BL/6J mice to describe the malformation that accompanies this condition. In mutant males a slight retardation in mandibular growth is observed. The neurocranium of mutants is shorter, more domed, and exhibits frontal and occipital bossing. Retardation in growth of the viscerocranium occurs. A characteristic protrusion of the frontopremaxillary suture is present at the junction of the neural and facial skulls. No differences in width are demonstrable. The malformation in mutant females is similar to that found in males but is less pronounced. The craniofacial malformations in humans with VDRR are generally similar to those described in the C57BL/6J-Hyp mouse.