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 Noonans Syndrome such as short stature, pulmonary valve stenosis, variable intellectual development, and skin pigment changes. Cardiofaciocutaneous (CFC) syndrome - CFC syndrome is very similar to Noonans 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 Noonans Syndrome. However, the conditions can be distinguished by their genetic cause.
Sulfasalazine (SSZ), sold under the trade name Azulfidine among others, is a medication used to treat rheumatoid arthritis, ulcerative colitis, and Crohns disease. It is considered by some to be a first-line treatment in rheumatoid arthritis. It is taken by mouth.Significant side effects occur in about 25% of people. Commonly these include loss of appetite, nausea, headache, and rash. Severe side effects include bone marrow suppression, liver problems, Stevens–Johnson syndrome, and kidney problems. It should not be used in people allergic to aspirin or sulfonamide. Use during pregnancy appears to be safe for the baby.Sulfasalazine is in the disease-modifying antirheumatic drugs (DMARDs) family of medications. It is unclear exactly how it works. One proposed mechanism is the inhibition of prostaglandins, resulting in local anti-inflammatory effects in the colon. The medication is broken down by intestinal bacteria into sulfapyridine and 5-aminosalicylic acid. That which is absorbed is excreted by the kidneys and in the bile.Sulfasalazine was approved for medical use in the United States in 1950. It is on the World Health Organizations List of Essential Medicines. Sulfasalazine is available as a generic medication. Medical uses
Sulfasalazine is used in the treatment of inflammatory bowel disease, including ulcerative colitis and Crohns disease. It is also indicated for use in rheumatoid arthritis and used in other types of inflammatory arthritis (e.g. psoriatic arthritis and reactive arthritis).It is usually not given to children under two years of age.