What Are Chromosomes, and How Many Pairs Are Present?
Long DNA molecules which hold the genetic information are called chromosomes. These chromosomes are present in the nucleus of each cell, meaning that every cell has 23 pairs of chromosomes. One chromosome is obtained from the mother, and one chromosome is obtained from the father to make a pair. Of the 23 pairs, the 22 pairs of chromosomes are the autosomes, and the last pair, the 23rd pair of chromosomes, is called the sex chromosome. These sex chromosomes determine the sex of an individual. In the case of males, one X chromosome and one Y chromosome are present, which is XX in females.
Therefore, the child's gender is solely dependent on the chromosome they receive from the father.
What Is Triple X Syndrome?
An uncommon genetic disorder known to affect only the female population is Triple X syndrome. In this syndrome, the affected female has three 'X' chromosomes, thus making the number of chromosomes 47. In women with triple X syndrome, there are chances for the presence of three X chromosomes in all the cells. While in some cases, only a few cells will have three X chromosomes, and the remaining will have the usual two chromosomes. This is called mosaicism. Depending on the number of cells with three X chromosomes, the degree of mosaicism is determined, ranging from a lower percentage to a percentage as close to 100 %.
What Are the Other Names of Triple X Syndrome?
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XXX.
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Trisomy X syndrome.
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47.
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Trisomy.
What Is the Prevalence Rate of Triple X Syndrome?
Triple X syndrome is seen in about one in every 1000 females. However, studies suggest that this syndrome is left undiagnosed in most cases due to its minimal symptoms.
What Are the Different Forms of Triple X Syndrome?
1. Mosaic:
This form of triple X syndrome occurs due to an incorrect cell division during the development of the embryo. In this type, not all cells will have three X chromosomes; instead, only a few cells will have the disorder. Since the number of cells affected is less, the symptoms are also not that significant.
2. Nondisjunction:
In the case of nondisjunction, the deformity occurs even before conception. Either the sperm of the father or the egg of the mother itself undergoes unwanted cell division, which produces an extra X chromosome.
What Causes Triple X Syndrome?
Triple X syndrome is a genetic disorder, yet not inherited from parents. It does not run in families. The changes in the genes can happen due to a random cause. The cause for the presence of three X chromosomes is an error during cell division, which can occur either before conceiving or during the embryo's developmental stage.
What Increases the Risk of Developing a Triple X Chromosome?
Since it is a rare genetic disorder, the risk factors of developing this disease are not apparent. However, it has been attributed that women who get pregnant above the age of 35 years are more prone to give birth to daughters with triple X syndrome.
How Is Triple X Syndrome Manifested?
Not all females experience the same degree of symptoms, and it varies according to the number of cells with three X chromosomes. There are no noticeable differences in some, while few significant signs may be seen.
The following are the characteristics of females with triple X syndrome:
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The above-average height is an important feature of females with triple X syndrome.
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Individuals might exhibit lower levels of intelligence as compared to their siblings.
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Problems with behavior like attention-deficit hyperkinetic disorder or autism. As a result, they exhibit difficulties in concentrating in school.
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Intellectual disability.
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Difficulty in learning.
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Mood disorders like anxiety and depression.
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Developmental delay of motor, speech, and language skills. Delay in motor skills is attributed to the fact that there is weak muscle tone and muscle fatigue.
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Inadequate communications skills.
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Hypertelorism (increased spacing between the eyes).
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Epicanthal folds (the inner corners of the eye are covered with vertical folds).
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Hypotonia or poor muscle tone.
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Clinodactyly (fingers appear small, pink, and curved).
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The feet appear flat.
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Inward bow-shaped breast bones.
In addition to the above, severe medical problems may be associated, which includes:
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Autoimmune hypothyroidism.
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Structural abnormality of the heart.
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Failure of the ovaries to produce eggs or ovaries may stop its function at a very young age.
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Malformations associated with the genitourinary system like the kidneys and ovaries.
How Is Triple X Syndrome Diagnosed?
In many cases, the condition remains undiagnosed due to the absence of significant symptoms. Even if they are diagnosed, they happen while looking for other conditions.
The presence of characteristics of triple X syndrome is an important diagnostic feature. In a few, diagnosis is made at later stages, when they exhibit signs like early menopause and fertility disorders.
The following tests are employed in the diagnosis of triple X syndrome:
1. Prenatal Testing:
Prenatal testing is used to diagnose triple X syndrome in an unborn baby. This test is done in women at an increased risk of delivering babies with triple X syndrome. Women who get pregnant at an advanced age, say 35 years or above, are recommended to take this test. Chorionic villi sampling, non-invasive prenatal testing (NIPT), and amniocentesis are the prenatal genetic tests.
2. Genetic Testing:
The presence of triple X syndrome can be confirmed with the help of genetic testing.
3. Chromosome Microarray or Karyotyping:
It helps detect an extra X chromosome present and the degree of masochism.
In addition, the below tests are recommended to determine the conditions associated with triple X syndrome:
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An echocardiogram or electrocardiogram is done to determine the abnormalities in the heart.
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Kidney structure is evaluated with the help of renal ultrasound.
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Neuropsychological testing.
What Is the Management for Triple X Syndrome?
This syndrome is not curable, and the symptoms and associated conditions can only be treated. The treatment depends on the associated symptoms.
1. Periodic Visits:
Developmental delays in the child should be assessed periodically.
2. Early Intervention Services:
Difficulties in speech, motor, and social skills should be intervened with the help of occupational, speech, developmental, and physical therapies at the right time. Occupational and physical therapies help in improving interaction, while speech therapy enhances reading, writing, and speaking skills.
3. Psychological Counseling:
In order to cope with emotional and behavioral disorders, counseling sessions should be encouraged for both the affected child and the parents. Thereby enabling the child and the parents to develop a behavior that can positively impact the child's learning and development.
4. Learning Assistance:
In children with difficulties in learning, educational assistance should be given to them to help them cope with the school tasks.
5. Estrogen Therapy:
In women with ovarian failure or premature dysfunction of ovaries that have resulted in early menopause, treatment with estrogen may be needed.
What Are the Complications of Triple X Syndrome?
The psychological, developmental, and social disorders that occur due to triple X syndrome result in the following complications:
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Low self-esteem.
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Problems with work, social, and school life.
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They might require assistance for day-to-day activities or school and workplace activities.
Can Triple X Syndrome Be Prevented?
As the cause is not clear in many cases, preventing the occurrence of the disease is not possible. Early diagnosis can be helped in providing the best treatment, which can be identified with prenatal genetic testing in women who get pregnant at an older age.
Conclusion:
Women with triple X syndrome can lead an everyday life in most cases. As far as treatment for triple X syndrome is concerned, early detection has a positive edge in managing the condition and reducing developmental delays associated. Prenatal genetic testing is an essential tool that can help in early diagnosis. If you or someone you know is carrying a baby at an increased age, it is vital to talk with a genetic counselor to rule out or attain an early diagnosis.
