Here, we describe patients with craniosynostosis and Noonan syndrome due to de novo mutations in PTPN11 and patients with craniosynostosis and CFC syndrome due to de novo mutations in BRAF or KRAS.
Furthermore, we suggest that the diagnosis should be refined to, for example, NS-PTPN11-associated or CFC-BRAF-associated syndromes after the genetic defect has been established, as this may affect the prognosis and treatment of the patients.
With our previous exclusion of PTPN11 mutations in CFC syndrome, these data suggest distinct genetic etiologies for Noonan, CFC and Costello syndromes.
The genetic cause of CFC syndrome remains unknown, and PTPN11 can be reasonably excluded as a candidate gene for the CFC syndrome, which we regard as molecular evidence that CFC and Noonan syndromes are distinct genetic entities.
Spectrum of mutations in PTPN11 and genotype-phenotype correlation in 96 patients with Noonan syndrome and five patients with cardio-facio-cutaneous syndrome.
The results showed no abnormalities in the coding region of the PTPN11 gene in any CFC patient, nor any evidence of major deletions within the gene suggesting that mutations in other gene(s) are responsible for this syndrome.