Triple X syndrome
Triple X syndrome
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.
Triple X syndrome may not cause any signs or symptoms. If symptoms do appear, they may include:
When to see a doctor
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.
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:
Preparing for your appointment
If you're concerned about your daughter's development, make an appointment to talk about it with your family doctor or pediatrician.
Because appointments can be brief, and there's often a lot of ground to cover, it's a good idea to arrive well prepared. Here's some information to help you get ready for your appointment, and what you might expect from your doctor.
What you can do
Your time with your daughter's doctor may be limited, so preparing a list of questions can help you make the most of your time together. For triple X syndrome, some basic questions you might want to ask include:
In addition to the questions that you've prepared in advance, don't hesitate to ask questions you may think of during your appointment.
What to expect from your doctor
Tests 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.
Treatments and drugs
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.
Coping and support
A number of groups can provide help and support for people with triple X syndrome and their families. They include Knowledge Support & Action, which offers information and advice on coping with the syndrome, as well as ways to meet and talk with others in similar situations. The phone number is 888-999-9428. In addition, your daughter's doctor may be able to recommend a local support group.
If learning disabilities appear, the National Center for Learning Disabilities is a good resource as well. It can be reached at 888-575-7373 or through its website.
Last Updated: 2012-11-08
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