Research
Spanish researchers reported the development of a Costello mouse, with the G12V mutation, in early 2008. Although the G12V mutation is rare among children with Costello syndrome, and the G12V mouse does not appear to develop tumors as expected, information about the mouse models heart may be transferable to humans. Italian and Japanese researchers published their development of a Costello zebrafish in late 2008, also with the G12V mutation. The advent of animal models may accelerate identification of treatment options. Historical
That genetic mutations in HRAS cause Costello syndrome was first reported in 2005. These mutations, along with mutations that cause cardiofaciocutaneous syndrome, found soon after, surprised geneticists and changed how genetic syndromes can be grouped. Before this, geneticists looked for new mutations in genes with mutations that caused syndromes similar to the unknown syndrome. For example, researchers looked at and around the most common Noonan syndrome mutation, PTPN11, but did not find anything related to Costello syndrome or cardiofaciocutaneous syndrome. The first mutation that is now identified as one of the Costello syndrome alleles was found unexpectedly when Japanese researchers used the DNA of children with Costello syndrome as a control, looking for another Noonan gene
Geneticists realized that the syndromes they were grouping together clinically according to their signs and symptoms were related in a way they had never realized: the mutations that cause Costello syndrome, Noonan syndrome and cardiofaciocutaneous syndromes are linked by their cellular function, not by being on or close to a gene with a known mutation.
Lastly, the frontal bone is divided into two, rotated and attached to the supraorbital bar causing a nude area (craniectomy) between the parietal bone and frontal bone. Bone will eventually regenerate since the dura mater lies underneath (the dura mater has osteogenic capabilities). This results in an advancement and straightening of the forehead. Floating forehead technique
The so-called floating forehead technique combined with the remodelling of the supraorbital bar is derived from the fronto-supraorbital advancement and remodelling. The supraorbital bar is remodelled as described above. The frontal bone is split in two pieces. Instead of using both pieces as in fronto-supraorbital advancement and remodelling, only one piece is rotated and attached to the supraorbital bar. This technique also leaves a craniectomy behind. Other
SuturectomyThe simplest form of surgery for trigonocephaly was suturectomy. However, as this technique was insufficient to correct the deformities, it is not used anymore. Distraction osteogenesisDistraction osteogenesis is based on creating more cranial space for the brain by gradually moving the bones apart. This can be achieved by using springs. Minimal invasive endoscopic surgeryThese approaches are 2D solutions for a 3D problem, therefore the results are not optimal. Distraction osteogenesis and minimal invasive endoscopic surgery are yet in experimental phase. Outcomes
Surgical
Trigonocephaly seems to be the most compliant form of craniosynostosis for surgery. Because of standardization of current surgical approaches there is no surgical mortality and complications are few to none. The simple suturectomy is presently insufficient to adjust the complicated growth restrictions caused by metopic synostosis.