Noonan syndrome (NS) is a complex genetic condition that results in various congenital abnormalities. These include distinctive facial features, reduced growth after birth, a webbed neck, a sunken chest, heart issues, a tendency to bleed, and in males, undescended testicles. This genetic disorder is also associated with a higher likelihood of developmental and language delays, learning disabilities, hearing impairments, and mild intellectual challenges. It is relatively prevalent, affecting approximately 1 in 1,000 to 2,500 newborns. The gene responsible for NS is located on chromosome 12q24.1, with over half of the cases caused by missense mutations in the PTPN11 gene, which encodes the SHP-2 protein tyrosine phosphatase. It is believed that these mutations result in excessive SHP-2 activity.
