Mutación en el gen SOS1 como nueva causa de síndrome de Noonan

Noonan syndrome, characterized by short stature, facial anomalies, heart disease and cryptorchidism in males, is an autosomal dominant, genetically heterogeneous disease. Approximately 50 % of Noonan syndrome cases are caused by gain-of-function mutations in PTPN11, encoding the tyrosine phosphatase (SHP2) and 5% are caused by KRAS mutations. Recently, a new mutation in SOS1 gene has been identified in approximately 20 % of cases of Noonan syndrome without PTPN11 mutation. That difference in genotype has a relationship with phenotype that we must investigate. We report a case of Noonan syndrome due to an SOS1 mutation; we describe his phenotype and subsequent outcome.