Triple X Syndrome. Mayo Clinic, 2012. Web. 7 Jan. 2014.
Triple X Syndrome (XXX)
Triple X syndrome is an abnormality of the chromosomes that affects about 1 in 1,000 females. Females normally have two X
chromosomes, one from each parent. In triple X syndrome, a female has three X chromosomes — hence, the name.
Triple X syndrome usually results from an error in the formation of a mother's egg cell or a father's sperm cell. Sometimes,
triple X syndrome occurs as a result of an error early in the embryo's development.
Many girls and women with triple X syndrome have no symptoms or only mild symptoms. In other cases, symptoms may be
more pronounced — possibly including developmental delays.
Treatment for triple X syndrome depends on which symptoms, if any, your daughter exhibits and their severity.
Symptoms
Triple X syndrome may not cause any signs or symptoms. If symptoms do appear, they may include:
 Tall stature
 Vertical skinfolds that may cover the inner corners of the eyes (epicanthal folds)
 Delayed development of speech and language skills
 Weak muscle tone (hypotonia)
 Curved pinky fingers (clinodactyly)
 Behavior and mental health problems
 Premature ovarian failure or ovary abnormalities
 Constipation or abdominal pains
Causes
Most people have 46 chromosomes occurring in 22 pairs, plus two sex chromosomes, one maternal and one paternal. These
chromosomes contain genes, which carry instructions that determine everything from your height to your eye color.
One of these chromosome pairs determines your sex. You receive one sex chromosome from your mother and another from
your father. Your mother can give you only an X chromosome, but your father can pass on an X or a Y chromosome. If you
receive an X chromosome from your father, the XX pair makes you genetically a female. If you receive a Y chromosome from
your father, then your XY pair means you're genetically a male.
Females with triple X syndrome have a third X chromosome. Although this condition is genetic, it's typically not inherited.
Instead, what usually happens is that either the mother's egg cell or the father's sperm cell has not formed correctly, resulting in
an extra X chromosome. This random error in egg or sperm cell division is called nondisjunction.
When the cause is a malformed egg cell or sperm cell, as is usually the case, all the cells in the offspring's body have the extra
chromosome. Occasionally, the extra chromosome doesn't appear until early in the development of the embryo. If this is the
case, then the female is said to have a mosaic form of triple X syndrome.
In the mosaic form, only some of the body's cells have the third X chromosome. Because only some cells contain the extra X
chromosome, females with the mosaic form of triple X syndrome may have less severe symptoms.
Triple X syndrome is also called trisomy X, triplo X syndrome and XXX syndrome. It's also referred to as 47,XXX syndrome
because of the existence of a 47th chromosome, which is the extra X chromosome.
Complications
Triple X syndrome can cause developmental delays or learning disabilities, and it's possible that learning disabilities or delayed
development could eventually lead to a variety of other issues, including academic problems, stress and poor socialization
skills that cause social isolation.
Other possible, though much rarer, complications that may occur include:
 Premature ovarian failure or ovary abnormalities. When the ovaries stop working before the expected age of
menopause, there's a decline in the production of certain hormones and eggs are no longer released by the ovaries each
month. This can cause infertility. Additionally, girls and women with triple X syndrome may have malformed ovaries.
 Seizures. Girls and women with triple X syndrome may develop a seizure disorder.
 Kidney abnormalities. Females born with triple X syndrome may also have abnormally developed kidneys or may
have only one kidney.
Test and Diagnosis
Because many girls with triple X syndrome are healthy and have a normal appearance, they may remain undiagnosed all their
lives, or the diagnosis may be discovered while investigating for other reasons.
Prenatal genetic testing, such as amniocentesis or chorionic villus sampling, can provide a diagnosis of triple X syndrome
before birth.
After birth, triple X syndrome can be diagnosed by performing a chromosome analysis on a blood sample taken from your
daughter.
Before genetic testing, it's important to receive genetic counseling to provide you with all the information about triple X
syndrome.
Treatment
If your daughter has triple X syndrome, treatment is based on her symptoms, if any are present. For instance, if she has a
learning disability from the triple X, she would require the same counseling as anyone else with that learning disability. This
counseling usually involves teaching new techniques and strategies for learning, as well as providing motivation and help with
using these tips in daily life.
If your daughter has been diagnosed with triple X syndrome, her doctor may recommend periodic screenings throughout
childhood. This would help ensure that any developmental delays or learning disabilities that may occur receive prompt
treatment.
Because girls with triple X syndrome may be more susceptible to stress, it's important to make sure your daughter has a
supportive environment as well. Psychological counseling may help, both by teaching you and your family useful methods of
demonstrating love and encouragement, and by discouraging behaviors that you might not realize are negative.
The chromosome change that causes triple X syndrome cannot be repaired, so the syndrome itself has no cure. However, given
the treatable nature of most symptoms and how frequently no symptoms appear at all, it's quite possible to lead a full and
normal life with this syndrome.