An inherited condition that shares many features with Turner’s syndrome, but in which there is a full complement of chromosomes. Noonan’s syndrome can affect both females and males. Features include congenital heart disease, webbing of the neck, myopia (short-sightedness), ptosis (drooping eyelids), feeding problems in infants, short stature, hearing difficulties, delayed puberty, delayed speech development, hypotonia (poor muscle tone), and undescended testes in men.
Noonan’s syndrome has an autosomal dominant pattern of inheritance. There is a family history of the condition in nearly half of all cases; the rest are due to new mutations. There is not a treatment for the condition, but most of its features (such as undescended testea and heart issues) can be treated successfully.