Noonan syndrome (NS) is characterized by short stature, congenital heart defect, and developmental delay of variable degree. Other findings can include broad or webbed neck, unusual chest shape with superior pectus carinatum and inferior pectus excavatum, cryptorchidism, characteristic facies, varied coagulation defects, lymphatic dysplasias, and ocular abnormalities. The prevalence of Noonan syndrome is approx 1 in 1,000 or 104,959 out of 104,959,594 people in Mexico. There is currently no single treatment for Noonan syndrome, but it's often possible to successfully manage many aspects of the disorder.
Severe heart defects may need to be repaired with surgery, and growth hormone medication may be used to help prevent restricted growth. Recurrence risk for parents who do not appear to be affected or who have only some facial features of Noonan syndrome is 5%.Gonadal mosaicism may account for this increase over population risk. Affected individuals have a 50% chance of passing on the disorder with each pregnancy. Alterations in four genes - PTPN11, SOS1, RAF1 and KRAS - have been identified to date.