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Syndrome Noonan: causes, symptoms, diagnosis, treatment
Last reviewed: 18.10.2021
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The Noonan syndrome is named after the author who described the disease in 1963. It occurs at a frequency of 1 per 1000-2500 newborns.
What causes Noonan's syndrome?
Syndrome Noonan is a hereditary autosomal dominant disease. In 50% of cases, molecular genetic verification of mutations of the PTPN11 gene is possible .
Symptoms of Noonan's Syndrome
In newborns there is a delay in growth (length at birth of 48 cm) with normal body weight. From birth, congenital heart defects (valve stenosis of the pulmonary artery, defect of the interventricular septum), cryptorchidism in boys in 60% of cases, combined deformity of the thorax are diagnosed. Various defects of coagulation factors (up to 50%) and dysplasia of the lymphatic system are frequent. Mental retardation occurs in 1/3 of patients.
How to recognize the Noonan syndrome?
Noonan syndrome is diagnosed on the basis of a combination of short stature, wide or pterygoid neck, chest deformity, congenital heart defects, unusual facial phenotype (frontal tubercles, hypertelorism, rotated ears with dangling curls).
What tests are needed?
Treatment of Noonan's Syndrome
Surgery
- Violations of the blood clotting system are detected in 20% of cases (deficiency of XI factor, Willebrand's disease, platelet dysfunction).
- There is an increased incidence of congenital chylothorax and chylopericard.
- Hypoplasia or aplasia of lymphatic vessels is found in 20% of cases in the form of generalized or peripheral lymphostasis, lung lymphangiectasis or intestinal wall, cardiosurgical interventions and damage to the lymphatic duct develop chylopericard or chylothorax.
- Malignant hyperthermia is possible with anesthesia, the probability is low (1-2%), but given the severity of this complication, caution should be exercised when conducting anesthesia. The use of the drug datrolene is shown.
What prognosis does the Noonan syndrome have?
It is determined by the spectrum of detected congenital defects and the presence of mental retardation.