Background The RASopathies are a class of human genetic syndromes that are caused by germline mutations in genes which encode components of the Ras/mitogen-activated protein kinase (MAPK) pathway. Cardiofaciocutaneous (CFC) syndrome is characterized by distinctive craniofacial features, congenital heart defects, and abnormalities of the skin and hair.
Objectives Systematically to characterize the spectrum of dermatological findings in mutation-positive individuals with CFC syndrome.
Methods Dermatological surveys were designed by the authors and distributed to the study participants through CFC International or directly by the authors (K.A.R. and D.H.S.) between July 2006 and August 2009. A second follow-up survey was collected between December 2007 and August 2009. When available, digital images and medical records of the participants were obtained. Study participants included individuals with CFC syndrome who have a mutation in BRAF, MAP2K1, MAP2K2 or KRAS.
Results Individuals with CFC syndrome have a variety of dermatological manifestations caused by dysregulation of the MAPK pathway in development. Numerous acquired melanocytic naevi were one of the most striking features: more than 50 naevi were reported by 23% (14/61) of participants and of those, more than 100 naevi were reported by 36% (5/14). Keratosis pilaris was reported in 80% (49/61) of cases. Ulerythema ophryogenes was common, occurring in 90% (55/61). Infantile haemangiomas occurred at a greater frequency, 26% (16/61), as compared with the general population.
Conclusions CFC syndrome has a complex dermatological phenotype with many cutaneous features, some of which allow it to be differentiated from the other Ras/MAPK pathway syndromes. Multiple café-au-lait macules and papillomas were not identified in this CFC cohort, helping to distinguish CFC from other RASopathies such as neurofibromatosis type 1 and Costello syndrome.