Genetics Northern California


There are five separate bones that make up the cranium of the head: the occipital bone (in the rear), two frontal bones (in the front), and two parietal bones (on the sides). The bones are similar to pieces of a jigsaw puzzle, separated by crooked lines called sutures. By five months of pregnancy, the bones form almost a complete covering of the brain except for the open spaces between them called soft spots, or fontanels. When a child is born, these sutures and soft spots are not fused to allow for both delivery and for growth during the first years of life. If, however, one of the sutures should fuse prematurely, the brain's growth is restricted and the skull will grow in different directions resulting in skull deformities. This premature fusing of the sutures is called craniosynostosis.

The causes of craniosynostosis are not known. Although most cases are sporadic, about 20% are associated with genetic syndromes. It may involve a single or multiple sutures. Disorders in fibroblast growth factor receptors, which are associated with bone growth, have been found in some cases of hereditary craniosynostosis. In general, craniosynostosis occurs in about 1 in every 2000 infants.

Sometimes, the diagnosis of craniosynostosis is confused with positional molding, sometimes referred to as positional plagiocephaly. Since the bones of the skull are particularly flexible in infancy and the baby is sleeping on his back, which is the recommended sleep position for infants, a particularly flat back or side of the head may result. It can be corrected by alternating sides of the head on which the infant rests. The child's pediatrician or pediatric nurse practitioner should be consulted and a referral to a physical therapist should also be made. This is not craniosynostosis, however. Craniosynostosis is the premature fusing of the cranial sutures. It does not correct itself over time and it does require surgery.

Surgery to open the cranial sutures is a common and often necessary treatment for craniosynostosis. Parents of a child with an abnormal head shape should request a physical exam and a series of X-rays from a skilled craniofacial team. These X-rays must be read by a skilled radiologist or neurosurgeon to avoid misdiagnosis. Surgery for craniosynostosis is often performed during the first year of life. Helmets or headband therapy may also be used as an adjunct to surgery in selected cases. In this type of therapy, the child wears a helmet or a headband for a prescribed period of time to direct proper skull growth.

Other Information
If a particular case of craniosynostosis is not related to a genetic syndrome, there are no real symptoms. The head shape is abnormal and occasionally the face may be malformed. Rarely, symptoms of increased pressure in the head such as headaches, decreased appetite, vomiting, or even developmental delays may occur. It is important, however, to seek the expertise of a craniofacial team to discuss treatments. Untreated craniosynostosis can cause damage or delayed growth to the brain. If a child's craniosynostosis is related to a specific syndrome, however, attention must be directed toward the specific symptoms and problems associated with the syndrome. Common syndromes with craniosynostosis as a physical manifestation include Apert, Crouzon, Pfeiffer, and Saethre-Chotzen (among others).


The National Craniofacial Association: Craniosynostosis - General information about craniosynostosis with links to related sites.

Craniosynostosis and Positional Plagiocephaly Support, Inc. - Provides support resources and information for individuals with craniosynostosis and their families.  


Last Reviewed: July 23, 2009 by Kimberly Barr, M.S.