What are the symptoms of Noonan syndrome ? 
 What are the signs and symptoms of Noonan syndrome? The Human Phenotype Ontology provides the following list of signs and symptoms for Noonan syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of the helix 90% Abnormality of the nipple 90% Abnormality of the palate 90% Abnormality of the pulmonary artery 90% Abnormality of the pulmonary valve 90% Aplasia/Hypoplasia of the abdominal wall musculature 90% Cystic hygroma 90% Enlarged thorax 90% High forehead 90% Hypertelorism 90% Joint hypermobility 90% Low-set, posteriorly rotated ears 90% Malar flattening 90% Muscle weakness 90% Neurological speech impairment 90% Pectus carinatum 90% Pectus excavatum 90% Proptosis 90% Ptosis 90% Short stature 90% Thick lower lip vermilion 90% Thickened nuchal skin fold 90% Triangular face 90% Webbed neck 90% Abnormal dermatoglyphics 50% Abnormality of coagulation 50% Abnormality of the spleen 50% Abnormality of thrombocytes 50% Arrhythmia 50% Coarse hair 50% Cryptorchidism 50% Delayed skeletal maturation 50% Feeding difficulties in infancy 50% Hepatomegaly 50% Low posterior hairline 50% Muscular hypotonia 50% Scoliosis 50% Strabismus 50% Intellectual disability 25% Abnormal hair quantity 7.5% Brachydactyly syndrome 7.5% Clinodactyly of the 5th finger 7.5% Hypogonadism 7.5% Lymphedema 7.5% Melanocytic nevus 7.5% Nystagmus 7.5% Radioulnar synostosis 7.5% Sensorineural hearing impairment 7.5% Abnormal bleeding - Amegakaryocytic thrombocytopenia - Atria septal defect - Autosomal dominant inheritance - Clinodactyly - Coarctation of aorta - Cubitus valgus - Dental malocclusion - Epicanthus - Failure to thrive in infancy - Heterogeneous - High palate - Hypertrophic cardiomyopathy - Kyphoscoliosis - Male infertility - Myopia - Neurofibrosarcoma - Patent ductus arteriosus - Pectus excavatum of inferior sternum - Postnatal growth retardation - Pulmonic stenosis - Radial deviation of finger - Reduced factor XII activity - Reduced factor XIII activity - Shield chest - Short neck - Superior pectus carinatum - Synovitis - Ventricular septal defect - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.