Noonan Syndrome Characteristics

Characteristics

Noonan syndrome was first identified in 1963 by two men Noonan and Ehmke. Noonan

Syndrome is classified as an autosomal dominant genetic disorder that presents with different physical attributes. NS is seen more frequently than one might assume, occurring between 1 and 1000-2500 births (Narumi et al., 2008). However, individuals may go undiagnosed when they present with a mild case of NS; therefore, the prevalence of NS could actually be higher (Wingbermuhle, Egger, Verhoeven, Burgt, & Kessels, 2011). Research has been done to target the specific gene mutation found in Noonan Syndrome. The mutation which causes the syndrome was found in the “RAS-Mitogen-Activated Protein Kinase (RAS-MAPK),” (Pierpont, Tworog-Dube, & Roberts,

“Noonan syndrome is characterized by distinctive facial features, short stature, congenital heart disease, skeletal anomalies, and other co morbidities” (Pierpont et al., 2014, p.385). Each of these characteristics can be common in individuals with Noonan Syndrome, yet they vary depending on the person. Short stature is only seen in around 50-60% of the population, and heart defects are found at a slightly higher rate of 50-62% in individuals. However, prevalence of heart defects increases to 85% if the individual has a gene mutation with PTPN11 (Pierpont et al., 2009). The most common type of heart defect found in those with Noonan Syndrome is pulmonary stenosis (Shaw, Kalidas, Crosby, Jeffery, & Patton, 2006). In regards to the specific facial features, the eyes and ears are key components to observe. The eyes are normally drooping and set wider than normal. The ears are often low and tilted slightly towards the back, with a “thickened helix”. The neck can be noted as wide and in some cases a “webbing” in the neck may be seen (Wingbermuhle et al., 2011). Facial features become harder to diagnosis as the individual ages due to the maturation process of the individuals appearances (Turner,

Learning disabilities may be an important aspect of Noonan Syndrome, yet not a lot of specific research has been done to grasp a better understanding of this. Since this avenue has not been aggressively studied for this syndrome demographic, learning impairments have been under identified (Pierpont et al., 2009). “The behavioral phenotype of Noonan Syndrome is characterized by a wide variability in most domains, with increased risk for motor delay, cognitive and language impairments, and learning difficulties,” (Pierpont et al., 2014, p.385). As with other syndromes, the more severe the case, the more likely the individual will present with severe cognitive or learning impairments (Pierpont et al.,