The principal values of making a genetic diagnosis are that it guides additional medical and developmental evaluations, it excludes other possible explanations for the features, and it allows more accurate recurrence risk estimates. With more genotype-phenotype correlation studies being performed, a positive genetic diagnosis will help the clinician to be aware of possible anomalies specific to that certain gene mutation. For example, an increase in hypertrophic cardiomyopathy is seen in people with a mutation of KRAS and an increased risk of juvenile myelomonocytic leukemia exists for a mutation of PTPN11. In the future, studies may lead to a targeted management of NS symptoms that depends on what genetic mutation a person has. Before birth Prenatal features that might lead physicians to consider a diagnosis of Noonan syndrome include cystic hygroma, increased nuchal translucency, pleural effusion, and edema. Differential diagnosis While Turner syndrome has similarities with renal anomalies and developmental delay, Turner syndrome is only found in females and often expresses differently. In Turner syndrome, there is a lower incidence of developmental delays, left-sided heart defects are constant and the occurrence of renal abnormalities is much lower. Other RASopathies Watson syndrome - Watson Syndrome has a number of similar characteristics with Noonan's Syndrome such as short stature, pulmonary valve stenosis, variable intellectual development, and skin pigment changes. Cardiofaciocutaneous (CFC) syndrome - CFC syndrome is very similar to Noonan's Syndrome due to similar cardiac and lymphatic features. However, In CFC syndrome intellectual disability and gastrointestinal problems are often more severe and pronounced. Costello syndrome - Like CFC syndrome, Costello syndrome has overlapping features with Noonan's Syndrome. However, the conditions can be distinguished by their genetic cause. Neurofibromatosis 1 (NF1) Williams syndrome Management The treatment varies depending on complications but tend to be quite standard, reflecting the treatment of the general population. Management guidelines, divided by systems, including general, developmental, dental, growth and feeding, cardiovascular, audiological, haematological, renal and skeletal, that account for actions to be taken at diagnosis, after diagnosis and if symptomatic, have been published by an American consortium. Specifically, treatment of cardiovascular complications resemble that of the general population and treatment of bleeding diathesis is guided by the specific factor deficiency or platelet aggregation. Neuropsychological testing is recommended to find strengths and challenges to tailor support needed for school and career. Educational customization such as an individualized education program plan is sometimes needed for school-aged children. Speech therapy if speech