This study will try to find the gene changes responsible for the birth defects in craniosynostosis, Philadelphia type. Craniosynostosis syndromes are a group of conditions that result from closure of one or more of the fibrous joints between the bones of the skull before brain growth is complete. Because of the premature closure, the brain is not able to grow in its natural shape; instead, it compensates with growth in areas of the skull where the joints have not yet closed. The defects in raniosynostosis, Philadelphia type, include skull malformations and webbing of the fingers and toes. Gene changes known to be involved in other craniosynostosis syndromes have not been found in the Philadelphia type syndrome. Therefore, finding the genetic basis of this disorder will provide important new information regarding craniofacial and limb development.