These respond well to speech therapy. The frequency of Noonan Syndrome may be as high as 1 per 1000 live births. All of our genes are in pairs, with one inherited from our mother and one from our father. This gene is strong, or dominant, so only one of the pair needs to be faulty for it to show itself. Perhaps 1 case in 4 is caused by a new mutation or change in the genetic information.
Women appear to pass on the different gene three times more often than men.
This phenomenon is attributed to reduced fertility in men, possibly as a result of persistent cryptorchidism. As stated earlier, chromosome analysis in people with Noonan Syndrome is normal. There is no cure for Noonan Syndrome, but a number of complications of Noonan Syndrome can be treated by surgery, medicine, special education, or speech therapy. A proportion of the heart defects require surgical correction. Surgery may also be performed to correct pectus excavatum and pectus carinatum, strabismus and ptosis, inguinal hernias and undescended testicles.