Turner Syndrome

     Turner syndrome results when all or part of one of the X chromosomes is lost before or soon after the time of conception. There is nothing that parents do to cause or increase the risk of TS in their daughters and nothing they can do to prevent it. In about half the cases of TS, one of the sex chromosomes is missing entirely, leaving 45 chromosomes instead of the usual 46. About 30% of girls with TS have some cells that have the normal number of chromosomes (46XX) and others that are missing an X (45X); this is thought to result from the loss of an X chromosome in some cells after fertilization. The presence of more than one chromosome pattern in an individual is called mosaicism. 45X/46XX mosaicism can be hard to diagnose because many body cells have the usual 46XX pattern. These girls may have fewer features of TS than girls whose cells are all missing an X chromosome. A small percentage of girls with TS have some Y chromosome material. Girls with all or part of a Y chromosome in any of their cells are at increased risk of developing tumors in their poorly developed gonads even during childhood, so surgical removal of the gonads generally is recommended. Another 20% of girls with TS have both X chromosomes, but one of them is incomplete or altered.

What are the features of Turner Syndrome?

Some girls with TS will have most of these features while other may have only a few of these features.  The phenotype of TS varies from person to person.

Physical Features

• short stature
• stocky appearance
• narrow, high arched palate
• retrognathia (receded lower jaw)
• broad chest
• widely spaced, inverted nipples
• cubitus valgus (arms that turn out slightly at the elbow)
• short ring finger (the bone in the hand is short not the finger itself)
• pectus excavatum (indented chest)
• webbed neck
• low posterior hairline
• prominent ears
• soft, narrow fingernails and toenails that point upward
• lymphedema (swelling of hands and feet)

Sexual Developement

• lack of sexual development
• infertility

Intelligence and School Performance

• difficulty imagining objects in relation to each other (visual-spatial processing, difficulty driving, and poor sense of direction)
• trouble appreciating subtle social cues such as facial expressions (social cognition)

• problems with nonverbal problem solving (math)
• clumsiness (psychomotor problems and poor manual dexterity

Heart and Vascular System

• coarctation of aorta (narrowing of aorta)
• bicuspid aortic valve
• aortic root dilation (enlargement of the aorta where it leaves the heart)
• hypertension (high blood pressure)
• horseshoe shaped kidneys

Ears and Hearing

• chronic ear infections
• hearing loss

Eyes and Vision

• strabismus (wandering or crossed eye)
• amblyopia (lazy eye)
• ptosis (droopy upper eyelids)
• red and green color blindness
• glaucoma (increased preasure inside the eye)

Bones and Teeth

• hip dislocation
• osteoporosis
• delayed bone age
• crowded teeth

Immune System

• hypothyroidism
• celiac disease (gluten sensitivity)
• inflammatory bowel disease
• juvenile rheumatoid arthritis

Metabolism

• high cholesterol
• Type II diabetes
• obesity
• increased insulin secretion
• increased uric acid secretion

Skin

• keloids (exaggerated scars)
• benign moles
• hemangiomas (benign tumors made up of newly formed blood vessels)
• seborrhea
• eczema

What are the treatments for Turner Syndrome?