Symptoms of Noonan syndrome include short stature, a webbed or broad neck, a characteristic facial appearance and congenital heart defects, explains the National Human Genome Research Institute. People may also have an unusual chest shape, mild developmental delays and bleeding or bruising problems. Up to 95 percent of people who suffer from Noonan syndrome have mild eye problems, while males may have undescended testes.
One of the key signs of Noonan syndrome is the person's facial appearance, notes Mayo Clinic. In early infancy, the child may have eyes that slant downward, low cast ears and a short neck. Children with Noonan syndrome appear expressionless, and as they approach adolescence, their face widens at the forehead and becomes pointed at the chin. Their neck lengthens to reveal folds of skin. Adults with Noonan syndrome may have wrinkled skin that appears transparent.
Eighty percent of individuals who have Noonan syndrome are born with congenital heart defects such as valve disorders, hypertrophic cardiomyopathy and structural defects such as a hole in the heart, according to Mayo Clinic. Due to feeding problems, the person may have delayed growth during his childhood and adolescent years. Eye conditions are very common in people with Noonan syndrome. They may have problems with eye muscles, resulting in conditions such as crossed eyes, or strabismus. They may also have refractive problems and problems with the nerves in their eyes. Kidney problems are rare and mild. Males may suffer from infertility due to undescended testes. Individuals with Noonan syndrome often have pale green or blue eyes and curly, sparse hair.