The RASopathies as an example of RAS/MAPK pathway disturbances - clinical presentation and molecular pathogenesis of selected syndromes.

The RASopathies are a class of developmental syndromes. Each of them exhibits distinctive phenotypic features, although there are numerous overlapping clinical manifestations that include: dysmorphic craniofacial features, congenital cardiac defects, skin abnormalities, varying degrees of intellectual disability and increased risk of malignancies. These disorders include: Noonan syndrome, Costello syndrome, LEOPARD syndrome, cardio-facio-cutaneous syndrome (CFC), capillary malformation-arteriovenous malformation syndrome (CM-AVM), Legius syndrome and neurofibromatosis type 1 (NF1). The RASopathies are associated with the presence of germline mutation in genes encoding specific proteins of the RAS/mitogen - activated protein kinase (MAPK) pathway that plays a crucial role in embryonic and postnatal development. In this review, we present the clinical and molecular features of selected syndromes from the RASopathies group.