Craniosynostosis as the Presenting Feature of X-linked Hypophosphatemic Rickets.

Craniosynostosis is the premature closure of cranial sutures. Primary, or congenital, craniosynostosis is often sporadic but may be associated with genetic or chromosomal abnormalities. Secondary craniosynostosis presents after gestation, and can occur in metabolic bone diseases, including rickets. We describe the first reported cases of primary craniosynostosis in 2 unrelated, term infants with X-linked hypophosphatemic rickets (XLH). The diagnosis of XLH in both patients was confirmed by genetic testing. At the time craniosynostosis was detected, the patient in the first case did not have any other clinical features of XLH. The second patient developed clinical findings of craniosynostosis, followed by rickets. These are the earliest reported cases of craniosynostosis in XLH and demonstrate that craniosynostosis may be a presenting feature of this disease.