Diseases

Noonan Syndrome

Back

Noonan syndrome is a disorder that involves unusual facial characteristics, short stature, heart defects present at birth, bleeding problems, developmental delays, and malformations of the bones of the rib cage. Noonan Syndrome is caused by changes in one of several autosomal dominant genes.

SYMPTOMS

Eyes are wide-set and down-slanting with droopy lids. Irises are pale blue or green.
Ears are low-set and rotated backward.
Nose is depressed at the top, with a wide base and bulbous tip.
Mouth has a deep groove between the nose and the mouth and wide peaks in the upper lip. The crease that runs from the edge of the nose to the corner of the mouth becomes deeply grooved with age. Teeth may be crooked, the inside roof of the mouth (palate) may be highly arched and the lower jaw may be small.
Facial features may appear coarse, but appear sharper with age. The face may appear droopy and expressionless.
Head may appear large with a prominent forehead and a low hairline on the back of the head.
Skin may appear thin and transparent with age.

CAUSES

Inherited. Children Who have one parent with noonan syndrome who carries the defective gene (autosomal dominant) have a 50 percent chance of developing the disorder.
Random. Noonan Syndrome can develop because of a new mutation in children who don't have a genetic predisposition for the disorder (de novo).