The following information may help to address your question:
Apert syndrome and the other conditions associated with FGFR-related craniosynostosis were clinically defined long before the molecular basis of this group of disorders was discovered. Apert syndrome can be diagnosed primarily based on the following clinical findings:
While clinical findings are suggestive of Apert syndrome, molecular genetic testing can help to confirm the diagnosis. Fibroblast growth factor receptor type 2 (FGFR2) sequence analysis is highly sensitive for Apert syndrome. More than 98% of cases are caused by a specific mutation in the 7th exon of the gene encoding FGFR2. The remaining cases are due to another specific mutation in or near exon 9 of FGFR2.