Drug therapies for those with cardiac abnormalities, as those abnormalities become severe enough to warrant the use of these therapies. ECGs are mandatory prior to any surgical interventions, due to possible arrythmia. Prognosis
In itself, NSML is not a life-threatening diagnosis, most people diagnosed with the condition live normal lives. Obstructive cardiomyopathy and other pathologic findings involving the cardiovascular system may be a cause of death in those whose cardiac deformities are profound. Epidemiology
Various literature describes the syndrome as being "rare" or "extremely rare". There is no epidemiologic data available regarding how many individuals have the syndrome worldwide; however, there are approximately 200 cases described in medical literature. History
Zeisler and Becker first described a syndrome with multiple lentigines, hypertelorism, pectus carinatum (protruding breastbone) and prognathism (protrusion of lower jaw) in 1936. Sporadic descriptions were added through the years. In 1962, cardiac abnormalities and short stature were first associated with the condition. In 1966, three familial cases were added, a mother, her son and daughter. Another case of mother to two separate children, with different paternity of the two children, was added in 1968.It was believed as late as 2002 that Noonan Syndrome with Multiple Lentigines (NSML) was related to neurofibromatosis type I (von Recklinghausen syndrome). In fact, since both ICD9 and ICD10 lack a specific diagnosis code for NSML, the diagnosis code for NF1 is still sometimes used for diagnostic purposes, although it has been shown that the gene is not linked to the NF1 locus.
These have irregular borders and range in size from 1 mm in diameter to café-au-lait spots, several centimeters in diameter. Also, some areas of vitiligo-like hypopigmentation may be observed. Electrocardiographic conduction abnormalities: Generally observed on an electrocardiograph as a bundle branch block. Ocular hypertelorism: Wideset eyes, which lead to a similar facial resemblance between patients. Facial abnormalities are the second highest occurring symptom after the lentigines. Abnormalities also include: broad nasal root, prognathism (protruding lower jaw), or low-set, possibly rotated, ears. Pulmonary stenosis: Narrowing of the pulmonary artery as it exits the heart. Other cardiac abnormalities may be present, including aortic stenosis, or mitral valve prolapse. Abnormal genitalia: usually cryptorchidism (retention of testicles in body) or monorchism (single testicle). In female patients, this presents as missing or single ovaries, much harder by nature to detect. Ultrasound imaging is performed at regular intervals, from the age of 1 year, to determine if ovaries are present. Retarded growth: Slow, or stunted growth. Most newborns with this syndrome are of normal birth weight and length, but will often slow within the first year. Deafness: Sensorineural (nerve deafness).The presence of all of these hallmarks is not needed for a diagnosis. A clinical diagnosis is considered made when, with lentigines present there are 2 other symptoms observed, such as ECG abnormalities and ocular hypertelorism, or without lentigines, 3 of the above conditions are present, with a first-degree relative (i.e. parent, child, sibling) with a clinical diagnosis.