Saethre Chotzen syndrome is a rare craniofacial syndrome which primarily affects the skull and facial bones. It frequently leads to fusion of the coronal sutures, resulting in a very characteristic skull shape. Saethre Chotzen syndroms is estimated to occur in 1 in 25,000-50,000 births.
Cause of Saethre Chotzen syndrome
Saethre Chotzen syndrome is caused by a mutation in the TWIST gene, located on Chromosome 7. In most cases, this mutation arises randomly or by chance. We do not yet fully understand what causes this mutation. However, it does not appear that the mutation occurs as a result of something either parent does or fails to do. Most parents who have a baby with Saethre Chotzen syndrome likely have normal genes.
Children with Saethre Chotzen syndrome can pass the gene on to their children, however. The mutation is passed in an autosomal dominant fashion, meaning that only one copy of the gene needs to be passed on for the new baby to have this syndrome. In practical terms, autosomal dominant inheritance means that there is a 50-50 chance of a parent with Saethre Chotzen syndrome having a baby that also has this condition. Anyone with Saethre Chotzen syndrome who wishes to have children should consider meeting with a geneticist in order to discuss the risks and make a thoughtful, informed decision.
The skull is comprised of a number of plates of bone, joined together at specialized joints called sutures. These sutures act like expansion joints, allowing the skull to get larger as your child grows and as the developing brain pushes outward. In Saethre Chotzen syndrome, some the coronal sutures fuse prematurely, preventing the skull from growing normally. Since the brain cannot push all parts of the skull outward as it grows, the brain instead pushes outward and upward in parts of the skull where these expansion joints are functioning. This leads to an abnormally shaped skull which tends to be shortened front to back and perhaps taller than it should be.
In addition to fused coronal sutures, children with Saethre Chotzen syndrome also have a characteristic low-set hairline, a “beaked” nose and short stature. These children also may have syndactylies – webbed appearing fingers, especially between the index and middle fingers. Children with Saethre Chotzen syndrome generally have normal intelligence and lead normal lives.
Most often, the diagnosis of Saethre Chotzen syndrome is suspected based on the abnormal skull shape and characteristic facial features. The suspected diagnosis is confirmed by a blood test to check for the TWIST gene mutation. This genetic work-up is often overseen by a geneticist who is familiar with craniofacial syndromes.
The treatment of Saethre Chotzen syndrome is focused on correction of the abnormal skull shape and mirrors the treatment of craniosynostosis. Although the timing of surgery can be highly individualized, surgical correction of the bicoronal craniosynostosis is most often done between 6 and 12 months of age. Surgery is usually performed through a scalp incision that lies concealed within the hair of the head. Your craniofacial surgeon will work in concert with a pediatric neurosurgeon in order to safely remove the bones of the skull. Then, the craniofacial surgeon reshapes and repositions those bones to give a more normal skull shape. Following surgery, your baby will spend at least one night in the pediatric intensive care unit prior to being transferred to a pediatric ward bed. You can anticipate that your baby will spend anywhere from 2-5 days in the hospital following surgery.