[Clinical symptoms and molecular pathogenesis of Noonan syndrome--current concepts].

Noonan syndrome (NS; MIM 163950) is an autosomal dominant disorder. With incidence of 1/1000 to 1/2500 live births, NS belongs to the most common genetic disorders. Typical features of NS are: short stature, chest deformities, congenital heart defects, cryptorchidism and dysmorphic features. Mutations of PTPN11 gene (located on chromosome 12q24.1) are responsible for NS and are identified in 33-60% cases. Less than half of the cases are familial. This paper presents current opinion on clinical symptoms, molecular pathogenesis and possibilities of growth hormone therapy. The genotype--phenotype correlation is also discussed.