Triple X syndrome is a condition in which a female is born with an extra X chromosome in each cell of the body. Those who have the extra chromosome in only some of their body cells are said to have triple X mosaicism.
Triple X syndrome is caused by the presence of an extra X chromosome in the cells of a female’s body. It was discovered in 1959 by Patricia Jacobs, a researcher working in a hospital in Scotland. The patient was a thirty-five-year-old woman who had undergone premature menopause. Although some girls with Triple X syndrome have learning disabilities or developmental delays, many do not. There are no unusual physical or medical disabilities associated with the syndrome; many girls with very mild symptoms may never be diagnosed. Researchers do not know why the extra copy of the X chromosome causes an increase in height and learning problems in some girls with the syndrome.
Triple X syndrome occurs in about one of every 900–1,000 girls born in the United States. It is estimated that between five and ten girls are born with the condition each day. As far as is known, the syndrome is equally common in all racial and ethnic groups. The only known risk factor for the syndrome is the mother’s age; women who are thirty-five or older when they become pregnant are at increased risk of having a daughter with Triple X syndrome.
Nursing Care Plan Signs and Symptoms
The most common cause of Triple X syndrome occurs when an egg carrying two copies of the X chromosome is involved in conception. The reason for the extra copy in the abnormal germ cell is a genetic error called nondisjunction. Nondisjunction is a random event and is not caused by anything either of the baby’s parents did or by any medications they may have taken.
During the normal process of germ cell formation, the paired chromosomes in the cell divide so that each daughter cell has only one member of the pair. In nondisjunction, one daughter cell gets both members of the chromosome pair and the other cell has none. If a germ cell carrying two copies of the X chromosome is fertilized by a normal germ cell from the other parent, the child will have three copies of the X chromosome. This genetic error is called a full trisomy X. Some girls affected by triple X syndrome children have some body cells with the extra copy of the X chromosome and some body cells without the extra copy. This condition is called mosaic trisomy X. About half of women with Triple X syndrome have the full trisomy X and the other half have mosaic trisomy X. Not all girls born with triple X syndrome have noticeable symptoms of the condition, which is why they may not be diagnosed for some years. In addition, girls with the normal number of X chromosomes may also have these features that are symptomatic of triple X syndrome:
• Slightly lower weight at birth
• Taller than other girls and women in the family
• Less coordinated; somewhat higher risk of developing back problems
• Development of language skills may be slowed
• Less assertive and quieter than most girls
• Increased risk of depression
• Intelligence that may be slightly lower than that of other girls and women in the patient’s family (Mental retardation is unusual.)
Girls with trisomy X go through puberty at the same age as girls with two X chromosomes and develop all the normal sexual characteristics of adult women. They are able to marry and have children, and do not need hormone treatments in order to become sexually mature. It is not yet known whether adult women with Triple X syndrome undergo menopause at an earlier age than most women because the condition has not been studied long enough for researchers to follow a significant number of subjects through adult life into menopause.
Nursing Care Plan Diagnosis
Triple X syndrome may never be diagnosed if the girl has no obvious symptoms. It can, however, be detected by amniocentesis before birth. Amniocentesis is a procedure in which the doctor withdraws a small amount of fluid from the sac that surrounds the baby in the mother’s uterus and examines cells from the baby’s tissues for genetic abnormalities. Triple X syndrome is sometimes discovered after birth if the girl has developmental delays or learning difficulties and is given a genetic evaluation.
Nursing Care Plan Treatment
There is no specific treatment for triple X syndrome; many doctors do not consider it a major disability. Girls with the syndrome who do have learning disabilities or emotional problems are given the same types of therapy as other children with the same conditions. An individualized treatment plan can be drawn up with the help of the girl’s doctor and teachers.
The most important aspect of treatment for the syndrome is love and support from the patient’s family. According to a Danish researcher who started one of the first triple X support groups in the world, “If conditions at home are good, stable and stimulating…learning problems rarely have any serious consequences. However, most triple X girls need remedial teaching at school at one time or another, and it is important that they get this help if and when they need it.”
The prognosis for girls with Triple X syndrome is generally good, particularly if their parents are loving and supportive. They are not at increased risk of other diseases as far as is known and have a normal life expectancy. They are less likely to complete college than other girls, but
almost all can finish high school with speech therapy or other additional help.While a few girls with triple X syndrome have some social difficulties, most are able to join the workforce, marry, and start families in adult life.
Nursing Care Plan Prevention
Because triple X syndrome is thought to be caused by a spontaneous genetic mutation rather than an inherited genetic defect, there is no way to prevent it.
It is possible that the increasing numbers of women having children in their thirties or forties will lead to an increase in the number of girls born with triple X syndrome. Little research has been done on triple X syndrome considering the numbers of girls affected by it; however, the conference hosted by the University of California, Davis, in 2006 offered some possible new directions. Papers were presented on the treatment of language difficulties, depression, anxiety, and developmental differences in girls with Triple X syndrome. Another presenter discussed the use of medications as part of treatment plans for these girls.