Gene risk for faulty skull closures in babies
An international team of 23 institutions has worked together to find two genetic biomarkers that increase the risk of the bones in babies' skulls fusing too early. Babies' skulls are designed to squeeze in during childbirth and then expand to keep up with the fast growth of the brain. To allow this, the five bony plates of the skull are linked by soft but tough membranes (soft spots or fontanelles) that start to turn into bone when the child is 18 months to two years old.
The final fusion of the sagittal suture (the seam that runs across the top of the head), doesn't normally happen until adulthood. When this last suture fuses too early, in sagittal craniosynostosis, the children can develop oddly-shaped heads as the brain tries to grow, and this distortion can lead to problems with vision and learning disabilities because of pressure on the brain. The disorder affects around one in 5,000 babies, and is more common in boys than girls. It is treated with surgery to allow the brain to grow normally.
In what the authors believe is the first genome-wide association study for this disorder, the team compared the genomes of children with the condition and their parents, who did not have the condition. They linked two SNPs (single nucleotide polymorphisms--changes in a single letter in the genetic code) to the disorder, both of which are in genes involved in development of the skeleton. The research was published in Nature Genetics.
"Our participation in this collaborative effort and our ongoing research into the biology of craniosynostosis will result in tangible changes in how we diagnose and treat craniosynostosis," says Michael Cunningham of Seattle Children's Research Institute.
The genetic biomarkers could help to spot the disorder earlier so that children can be monitored and treated. They could also be used to provide genetic counseling and support for affected families planning another child.