Are Autism and Craniosynostosis Associated?

Reviewed by Terri Forehand RN
pediatric neurologist

Autism and craniosynostosis are both disorders than can affect a child's neurological development, and there is limited evidence that these conditions may be linked in some cases. Craniosynostosis, a condition in which the bones of the skull fuse too early, can cause too much pressure on a child's brain and can lead to learning disabilities and problems with language development. Autism shares a few traits with this disorder, and in some cases, it may even share a genetic cause.

Studies Linking Autism and Craniosynostosis

The Mayo Clinic reports that craniosynostosis is usually treated with surgery very early in a child's life; however, if left untreated, it can lead to seizures, facial deformities, blindness, and brain damage. Even with surgery, it can cause a variety of behavioral and learning challenges.

Some of these challenges are similar to those of autism, which may be what prompted researchers to study the two disorders for a potential link. There are a few studies that indicate these two conditions could be related in some specific cases.

Evidence of Comorbidity With One Type of Craniosynostosis

Depending on which parts of the skull fuse together, craniosynostosis can take on many different traits and names. One of these is "trigonocephaly," also known as "metopic synostosis." According to Boston Children's Hospital, trigonocephaly involves fusing of the metopic suture, which runs down the center of the forehead.

There have been several studies linking this type of craniosynostosis with autism, including some that showed the autistic symptoms could be reversed with surgery:

  • A 2012 study published in Plastic & Reconstructive Surgery examined 82 patients with trigonocephaly to determine how many of them had certain behavioral disorders, including autism. The study found that in patients with an IQ of less than 85, there was a 70% chance that the individual also met the diagnostic criteria for autism or another behavior disorder.
  • A 2009 study in Radiology and Nuclear Medicine examined 300 patients before and after surgery for trigonocephaly. Of those patients showing autistic tendencies, there was a 76.5% improvement in symptoms following the surgery.
  • Another small study from 2012 took on the issue of improvement after surgery in the journal Child's Nervous System. It found that among 34 children with trigonocephaly and developmental disorders, including autism, there was a significant improvement in symptoms following surgery.

Limited Evidence for a Possible Shared Genetic Cause

A variety of genetic syndromes and mutations can cause cranosynostosis, but one of these possible mutations may involve the X chromosome. A 2013 case study, which was published in European Child & Adolescent Psychiatry, looked at the genetic information of two brothers who had craniosynostosis and autism. These brothers had an extra copy of a few specific genes that predisposed them to autism. Prior to this study, researchers had not found that duplication of these genes could also result in craniosynostosis.

It's important to note that this is only a case study of two people, so it is difficult to extrapolate to the general population. More research needs to be done to determine if these two disorders share a genetic cause.

Suspected Autism Teratogen

Autism and craniosynostosis may also share at least one teratogen, or substance that causes birth defects when taken by pregnant women. Valproate, a drug used to control epilepsy, has long been linked to autism. A 2005 study published in the journal Neurology also suggests a link between valproate and craniosynostosis. The study found that if women were exposed to valproate during the first trimester, their babies were significantly more likely to develop major malformations like craniosynostosis.

Common Symptoms of Craniosynostosis and Autism

Since both craniosynostosis and autism affect the brain, they can have a few common symptoms, including the following:

  • Seizures - A common symptom of untreated craniosynostosis, seizures also affect about 35% of people with autism, according to the Autism Research Institute.
  • Delayed language - According to research conducted by the Yale Child Study Center, both autism and craniosynostosis can have very similar patterns of language delay and similar challenges in processing speech sounds.
  • Motor challenges - A review of the literature published in Developmental Neurospsychology found that motor challenges are common among children with craniosynostosis. According to the Simons Foundation Autism Research Initiative, 80% of children with autism also have motor challenges.

More Research Is Needed

It's important to note that there are only a few studies linking the autism and craniosynostosis. More research needs to be done before doctors can reliably consider the two disorders linked. If you suspect your child has either of these conditions, it's important that you talk to your pediatrician right away. Whether or not they are associated, both autism and craniosynostosis respond to early intervention.

Are Autism and Craniosynostosis Associated?