Triple X syndrome

Triple X syndrome

Overview

Triple X syndrome, also called trisomy X or 47,XXX, is a genetic disorder that affects about 1 in 1,000 females. Females normally have two X chromosomes in all cells — one X chromosome from each parent. In triple X syndrome, a female has three X chromosomes.

Many girls and women with triple X syndrome don't experience symptoms or have only mild symptoms. In others, symptoms may be more apparent — possibly including developmental delays and learning disabilities. Seizures and kidney problems occur in a small number of girls and women with triple X syndrome.

Treatment for triple X syndrome depends on which symptoms, if any, are present and their severity.

Symptoms

Signs and symptoms can vary greatly among girls and women with triple X syndrome. Many experience no noticeable effects or have only mild symptoms.

Being taller than average height is the most typical physical feature. Most females with triple X syndrome experience normal sexual development and have the ability to become pregnant. Some girls and women with triple X syndrome have intelligence in the normal range, but possibly slightly lower when compared with siblings. Others may have intellectual disabilities and sometimes may have behavioral problems.

Occasionally, significant symptoms may occur, which vary among individuals. These signs and symptoms may show up as:

Delayed development of speech and language skills, as well as motor skills, such as sitting up and walking

Learning disabilities, such as difficulty with reading, understanding or math

Behavioral problems, such as attention-deficit/hyperactivity disorder (ADHD) or symptoms of autism spectrum disorder

Psychological problems, such as anxiety and depression

Problems with fine and gross motor skills, memory, judgment and information processing

Sometimes females with triple X syndrome have these signs and symptoms:

Vertical folds of skin that cover the inner corners of the eyes (epicanthal folds)

Widely spaced eyes

Curved pinky fingers

Flat feet

Breastbone with an inward bowed shape

Weak muscle tone (hypotonia)

Seizures

Problems with the kidneys

Ovaries that don't work properly at a young age (premature ovarian failure)

Causes

Although triple X syndrome is genetic, it's usually not inherited — it's due to a random genetic error.

Normally, people have 46 chromosomes in each cell, organized into 23 pairs, including two sex chromosomes. One set of chromosomes is from the mother and the other set is from the father. These chromosomes contain genes, which carry instructions that determine everything from height to eye color.

The pair of sex chromosomes — either XX or XY — determines a child's sex. A mother can give the child only an X chromosome, but a father can pass on an X or a Y chromosome:

If the child receives an X chromosome from the father, the XX pair makes the child genetically female.

If the child receives a Y chromosome from the father, the XY pair means the child is genetically male.

Females with triple X syndrome have a third X chromosome from a random error in cell division. This error can happen before conception or early in the embryo's development, resulting in one of these forms of triple X syndrome:

Nondisjunction. In most cases, either the mother's egg cell or the father's sperm cell divides incorrectly, resulting in an extra X chromosome in the child. This random error is called nondisjunction, and all the cells in the child's body will have the extra X chromosome.

Mosaic. Occasionally, the extra chromosome results from an incorrect cell division caused by a random event early in the embryo's development. If this is the case, the child has a mosaic form of triple X syndrome, and only some cells have the extra X chromosome. Females with the mosaic form may have less obvious symptoms.

Triple X syndrome is also called 47,XXX syndrome because the extra X chromosome results in 47 chromosomes in each cell instead of the usual 46.

Risk factors

There are no major risk factors for Triple X syndrome. Most cases are due to a random error in the division of cells in the mother's egg, the father's sperm or when the embryo is developing.

Complications

Although some females may have mild or no symptoms associated with triple X syndrome, others experience developmental, psychological and behavioral problems that may lead to a variety of other issues, including:

Work, school, social and relationship problems

Poor self-esteem

Need for additional support or assistance with learning, activities of daily living, school or work

Diagnosis

Because many girls and women with triple X syndrome are healthy and show no outward signs of the condition, they may remain undiagnosed all their lives, or the diagnosis may be discovered while checking other issues. Triple X syndrome may also be discovered during prenatal testing to identify other genetic disorders.

During pregnancy, a sample of the mother's blood can be tested to check the baby's DNA. If the test shows an increased risk of triple X syndrome, a sample of fluid or tissue from inside the womb can be collected. Genetic testing of the fluid or tissue will show if there's an extra, third, X chromosome.

If triple X syndrome is suspected after birth based on signs and symptoms, it can be confirmed by genetic testing. In addition to genetic testing, genetic counseling can help you gain comprehensive information about triple X syndrome.

Treatment

The chromosome error that causes triple X syndrome can't be repaired, so the syndrome itself has no cure. Treatment is based on symptoms and needs. Options that may be helpful include:

Periodic screenings. The health care provider may recommend periodic screenings throughout childhood and into adulthood. If any developmental delays, learning disabilities or health problems occur, prompt treatment can be provided.

Early intervention services. These services may include speech, occupational, physical or developmental therapy, starting in the early months of life or as soon as needs are identified.

Educational assistance. If your child has a learning disability, educational help to learn techniques and strategies to be successful in school and daily life can be provided.

Supportive environment and counseling. Girls and women with triple X syndrome may be more prone to anxiety, as well as behavioral and emotional problems. So make sure your child has a supportive environment. Psychological counseling may help teach you and your family how to demonstrate love and encouragement and discourage behaviors that might negatively impact learning and social functioning.

Assistance and support in daily functioning. If your child has problems that impact daily functioning, this assistance and support may include help with activities of daily living, social opportunities and employm Type of Doctor Department :  ent.

Type of Doctor Department : A paediatrician