Noonan syndrome.

Noonan syndrome is a common autosomal dominant condition caused by multiple genes in the RasMAPK pathway. The adult phenotype can be extremely subtle, and many adults are diagnosed only after the birth of a more obviously affected child. Whether diagnosis is made in childhood or adulthood, initial and ongoing evaluation of many systems can have considerable health benefits. (c) 2007 Wiley-Liss, Inc.