Turner syndrome: see causes, characteristics, karyotype

What is Turner Syndrome?

Turner syndrome is a condition that affects girls only  and is caused by a genetic change. The human sex chromosome is usually represented by the combinations XX (girl) and XY (boy). Turner’s syndrome happens when only one of the X’s is functional. It can be caused when one of the X chromosomes is damaged or completely missing.

The condition is often caused by a problematic sperm. The condition is not transferred genetically, as the patients are sterile. The mutation is always random and the condition is very rare.

It affects about 1 in every 2500 births of girls, but it is much more common than that in pregnancies that do not end, as 90% end in spontaneous abortions, leaving the condition even more rare to be found.

It is important to note that Turner’s syndrome is not a disease, but a condition . There is no talk of symptoms, but of characteristics, just as there is no talk of a cure.

Types

There are three types of Turner syndrome:

Monoxomy

Approximately 50% of cases are in this classification. It is the classic definition: instead of two sex chromosomes (XX or XY), all cells of the person have only one X chromosome.

Turner’s syndrome is the only viable monosomal condition. Most cases of it result in spontaneous abortion, but some children can be born alive with just one X chromosome. If any other chromosome is completely missing, the person is not able to survive.

Mosaicism

Mosaic Turner’s syndrome is a little different. Their characteristics are the same, but they are often less intense. In these cases, not all of the person’s cells have monosomy (presence of only one chromosome). A portion of the patient’s cells may have both X chromosomes.

In some rare cases, it is possible for parts of the Y chromosome to be present in some of the cells. It is also considered mosaicism and the characteristics are the same as for monosomy, with the addition of an increased risk of gonadoblastoma , a type of cancer .

Mosaicism is not exclusive to Turner’s syndrome. Any genetic change that is repeated only in a portion of the person’s cells is considered a genetic mosaic .

X chromosome abnormalities

In this type of Turner syndrome, instead of being completely absent, one of the X chromosomes is damaged in every cell in the body. When this abnormality comes from the gametes (egg or sperm), it affects all cells. When the error occurs in the first cell divisions, only a few of them will be damaged, causing a type of mosaicism.

Causes

Turner’s syndrome is caused by the lack or abnormality of the second X chromosome. To understand this, it is necessary to know a little bit of genetics.

Humans have 46 different chromosomes in their DNA, divided into 23 pairs. Each carries instructions on how cells should reproduce, what proteins should be created and how to behave. It is the chromosomes that define each trait of our appearance: skin color, eyes, hair, our height, among other things, such as our biological gender.

Gametes, which are the reproductive cells (sperm in the case of men and eggs in the case of women) carry half the genetic load, each with 23 chromosomes, without pairs. When the sperm fertilizes the egg, the pairs form and the DNA of the child to be born is formed.

The last of the pairs is the sex chromosome pair. They define our biological gender. These chromosomes can be XX  (girl) or XY  (boy).

The egg always has an X, since the woman’s sex chromosome pair is always XX. The sperm can bring an X or a Y. If he brings the X, a girl will be born, if he brings the Y, a boy.

Turner’s syndrome is caused when the second sex chromosome is missing or damaged. The result is that the person has only 45 chromosomes, one less than he should have. Most of the time this happens because the sperm brought a damaged sex chromosome or brought none.

Due to the lack of the Y chromosome, which is what makes the fetus develop male characteristics, people with Turner syndrome are always girls.

It is the only viable monosomy in human beings. This means that it is the only condition that happens due to the complete lack of a chromosome. Any other fault makes the fetus unfeasible, which cannot be born alive.

Streaming

Turner’s syndrome cannot be transmitted. The patient is born with the condition and cannot transfer it to others. In addition, unlike many genetic conditions and diseases, this is not transferred to the patient’s descendants.

First, in the vast majority of cases, women with Turner syndrome are infertile and cannot have children. Furthermore, in cases where there is a possibility of pregnancy, the disease cannot be passed on as there is no gene that causes it, but the lack of one and the chances that this pregnancy will result in another child with Turner is the same other women.

It is important to note that the pregnancy of someone with Turner is always at risk and must be closely monitored by a doctor.

Risk factors

If you are already born and do not have the condition, you will not have it. However, it is important to note that the characteristics are present in different intensities, so it is not always possible to identify them in the early stages of life.

Sometimes, the girl may have the condition diagnosed only during adolescence and there are cases where women discovered Turner’s syndrome only when they had problems with having children.

It is very difficult for this to happen, however, since the condition itself is already rare. Instances in which its characteristics are so discrete as to go completely unnoticed until adulthood are isolated cases.

Characteristics

Several of the characteristics of Turner syndrome are usually clear and visible from birth, when most diagnoses of the condition are made. In this list, the words “very common”, “frequent” and “infrequent” indicate that that specific characteristic is present in more than 50% of the cases (very common), less than 50% of the cases  (common) and less than 5 % of cases (uncommon). The main ones are:

Winged neck

Frequent . The so-called winged neck is an excess of skin and soft tissue in the neck and shoulders, open on the side of the neck, giving an enlarged appearance to it. It is one of the most common signs of the disease.

Low hairline

Very common. The hairline can be low, starting in the middle of the neck. That is, there is a low implantation of hair on the nape of the neck.

Hormonal problems

Very common . Female hormones, such as estrogen, may be present in low amounts or none at all.

Retrognathism

Very common . Retrognathism is a condition of the jaw that causes it to recoil and malform. There are risks of causing breathing problems and difficulty closing your mouth.

Swollen hands and feet at birth

Very common . Due to swelling of the lymphatic system, the child may be born with swollen feet and hands, these being one of the main signs that doctors perceive at birth for diagnosis. The swelling usually goes away after a while.

Slow growth

Very common . The child with Turner’s syndrome grows slowly and this has been happening since before birth.

The person is short and the average height of patients with Turner syndrome who have not undergone hormone treatment for growth is 143 cm, 20 centimeters less than the female average. This is because part of the missing X chromosome is responsible for growth, as well as hormonal problems.

The growth rate of the person with the syndrome is low for most of his life. It is normal only between birth and three years of age, but during this period your bone development is slowed down, as well as after the age of ten, when the bones suffer severe developmental delays.

Late or absent puberty

Very common . The nipples can become too separated and the characteristics of sexual maturation, such as breast and hair growth, may not appear or be reduced, as well as the height of adolescence.

Amenorrhea

Very common . Because of absent sexual maturation and undeveloped ovaries, the patient may experience amenorrhea, which is the complete lack of menstruation. This symptom, added to infertility, is usually the sign that raises the suspicion of the condition in adults who have not been diagnosed.

Cardiovascular problems

Frequent . Narrowing of the aortic vein is a common problem faced by patients with Turner syndrome. Other heart problems can appear, such as hypertension and ischemic heart disease.

These changes affect between 20% and 40% of patients with the syndrome and are even more common in people with the monosomal version of the condition than in the mosaic.

Kidney problems

Frequent . Some women who have Turner syndrome may suffer from problems with kidney formation and the organs may malfunction. Malformations of the renal system can cause hypertension and recurrent urinary infections.

Inflammatory bowel disease

Uncommon . Also known as Crohn’s disease , the person with Turner’s syndrome has a higher risk of having inflammatory bowel disease, which causes abdominal pain, fatigue , anemia and weight loss.

Bone problems

Frequent . Due to the hormonal lack of estrogen, the syndrome’s bones may be more fragile, leading to osteoporosis and bone growth difficulties. These problems affect around 50% of patients with Turner syndrome.

Among the conditions that can appear are scoliosis and osteoporosis, which is a risk to the bones of people with the condition. Especially from 55 years of age, these bones can become fragile and break easily.

Autoimmune diseases

Frequent . Between 25% and 30% of patients with Turner syndrome have autoimmune diseases related to thyroid. The hypothyroidism is more common than hyperthyroidism , but both can affect the patient.

Metabolic changes

Very common . Due to metabolic problems, obesity is common in patients with Turner syndrome, especially between 5 and 7 years old and during adolescence. Food education is especially important to prevent weight problems.

Neurological problems

Frequent . Turner’s syndrome has been associated with mental retardation for a long time, but it has been proven that there are few cases that present this. However, it is common for neurological problems, such as lack of spatial coordination.

Superior verbal skills

Frequent . Verbal skills – skills in the use of words for communication – are often superior to that of women who do not have the condition.

Other problems

The condition can bring several other malformations to the carrier’s body. Are they:

  • Tall and narrow mouth palate;
  • Drooping eyelids;
  • Hearing problems;
  • Dry eyes;
  • Wide chest with widely spaced nipples;
  • Short fingers;
  • Narrow nails;
  • Scoliosis;
  • Flat feet;
  • Extra skin over the neck;
  • Low ears.

How is the diagnosis made?

The diagnosis of the condition can be made at any time in life, including during prenatal care. It is common for characteristics at birth to leave the presence of the syndrome clear, but confirmation is made after the karyotype test, carried out by the  geneticist .

Karyotype

This test is used to confirm Turner’s syndrome. It can be done with a sample of blood, saliva or hair from the patient. Microscopic analysis of the sex chromosomes is performed and, if one of the X chromosomes is missing or damaged, Turner’s syndrome is confirmed.

From the 9th week of pregnancy it is already possible to take the test to find out if the child will have the condition. In this case, the exam is performed on cells of the placenta or amniotic fluid, removed through processes called chorionic villus biopsy  or  amniocentesis .

Prenatal suspicion

Normally, the examination of the karyotype is not performed on developing fetuses unless there is a suspicion.

This suspicion, in the case of Turner syndrome, can be achieved through some tests, such as prenatal ultrasound, which is able to identify anomalies and malformations in babies. Depending on this formation, suspicion is born.

It is known that patients with Turner Syndrome tend to be born with swollen feet and hands, have a short femur during pregnancy and have cardiac and renal abnormalities. These changes can be seen during the ultrasound, raising suspicions and leading to an examination of the karyotype.

Is there a cure?

There is no mention of “cure”. Turner’s syndrome is a genetic condition and not a disease, so it cannot be cured. The carrier of the syndrome will carry it with you for the rest of your life in the same way that it will carry the color of your eyes.

What is the treatment?

Treatment is purely symptomatic. It seeks to reduce symptoms, increasing the quality of life of the person with the condition.

Hormonal treatment

Estrogen deficiency affects between 95% and 98% of girls with Turner syndrome and only about 20% of women with the syndrome secrete enough hormones for spontaneous sexual maturation.

Because of this, hormonal treatment can be used for the development of eggs, forcing a puberty that would not come otherwise and thus guarantee the development of sexual characteristics.

The ovaries are the only part of the female reproductive system that depends on hormonal action for their development, and this treatment ensures that. It can start to be applied between 12 and 15 years of age.

Hormonal treatment is also usually performed to increase the patient’s growth rate. Growth hormones can be used since childhood in some cases.

Surgical treatment of malformations

Malformations can be resolved through surgery, but the main target of these corrections is cardiac conditions, which pose a greater risk to the patient.

Condition monitoring

During childhood and adolescence, monitoring the condition is very important to improve the patient’s quality of life, ensuring a more complete development through hormonal treatment when necessary.

Monitoring your heart and kidney condition is also important as it can prevent serious problems with your heart and kidneys.

Fertility treatment

In the vast majority of cases a woman with Turner syndrome is infertile, but if she wishes, she can have children through fertility treatment. It is possible to receive egg donation after hormonal treatment for the preparation of the uterus.

There is a possibility that the child will be born with the syndrome, but the chances of this happening are exactly the same as for a birth from a woman without the condition. Therefore, there is no risk that the disease will be passed from the mother to the child.

It is important to note that a pregnancy with Turner syndrome is always at risk. The doctor should be consulted to evaluate the options and if there is any viability in the case.

Medicines

The medicine used to treat the condition is growth hormone:

  • Somatropina

Attention!

NEVER  self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.

Living together

Although the syndrome allows a normal life, it is important that there is some extra care for the carriers.

Medical team

The monitoring of a medical team is important due to some problems that can be caused by the condition. Visits to the cardiologist  may be relevant, as people with this genetic disorder are more prone to heart problems.

The endocrinologist  is also important to help with hormonal application and thyroid problems.

Taking the child to the orthopedist  from time to time may be recommended, thus taking care of the bone structure of the person with Turner syndrome.

In addition, the following professionals can help you live with the disease:

Gynecologist

Since Turner’s syndrome can cause problems in sexual development, the gynecologist can help with this area.

Geneticist

The geneticist is the one who makes the diagnosis of Turner syndrome. He may encounter other genetic conditions, in addition to being the doctor able to indicate the following steps after diagnosis.

Urologist

The urinary system can be affected by malformations and the urologist is the professional indicated to monitor this area.

Otolaryngologist

Ear, nose and throat problems can arise and this professional is responsible for these areas.

Gastroenterologist

Malformations in the digestive system can occur and the gastroenterologist is the professional who will monitor this part of the body.

Ophthalmologist

Ophthalmological follow-up is important to check eye health.

Speech Therapist

Hearing and speech problems may be present due to malformations of the auditory system and the jaw. The speech therapist can help.

Orthodontist

The orthodontist is responsible for the care of the mouth and teeth. The Turner syndrome patient, due to her malformations, may need special attention.

Psychologist

The condition can bring problems of self – esteem for the carrier, among other psychological problems. It is important that there is monitoring by a psychologist, seeking to ensure mental health .

Prognosis: what is the life expectancy?

The patient who has Turner’s syndrome can live a normal and happy life. The complications of the condition are real, but it is possible to prevent and mitigate them.

In cases where it is possible to have a pregnancy through fertility treatment, it must be remembered that these pregnancies are at risk and special care must be taken.

The life expectancy of women with Turner is less than that of women without the condition. This reduction is around 10 and 13 years less than the life expectancy of women without the syndrome, at the same age.

Complications

There are several complications that can be caused by Turner’s syndrome if there is no medical care. Some of them are:

osteoporosis

Due to the lack of estrogen, the patient’s bones can become fragile. Fractures can be common and dangerous.

Kidney problems

People with Turner syndrome may have kidney malformations. They do not always cause problems, but it is possible that they result in an increased risk of high blood pressure and urinary tract infections.

Hypothyroidism

The genetic change can lead to thyroid changes, leading to hypothyroidism.

Scoliosis

Scoliosis is often found in patients with Turner syndrome due to bone malformations.

Heart murmur

The narrow aorta, in addition to hypertension, can lead to heart murmurs, which is a turbulence in the passage of blood through the heart.

Learning difficulties

Girls with Turner syndrome tend to have normal and preserved intelligence, but there is a greater risk of developing learning disorders, especially when they involve attention, memory, math and spatial awareness.

Risky pregnancy

The pregnancy of a person with Turner syndrome is at risk, due to the increased risks of complications such as high blood pressure and changes in the aorta. A doctor should be consulted before a pregnancy when it is possible and desired and follow-up is extremely important.

Other complications

In addition to these, other complications can be found more frequently than in people without the syndrome:

  • Diabetes;
  • Obesity;
  • Lymphedema;
  • Digestive Bleeding;
  • Crohn’s disease.

How to prevent

It is not possible to prevent Turner’s syndrome. The mutation is completely random and is not due to a condition of the parents. Therefore, it is not possible to have tests to find out whether or not there is a chance of a child having the syndrome. Everyone has this chance and everything depends on the correct combination of chromosomes in fertilization.

It is important, however, to make the diagnosis as soon as possible. This guarantees a superior quality of life for the carrier of the syndrome.

Common questions

Can a woman with Turner syndrome have an active sex life?

Yea! Nothing prevents the sex life of a woman with Turner syndrome. It is recommended to visit a gynecologist to check how the reproductive system is doing. Although most women with Turner syndrome are infertile, some can become pregnant without fertility treatment. It is best not to be caught off guard.

What is the medical field of Turner syndrome?

Turner’s syndrome is not a disease, but the medical specialist indicated for consultation is the geneticist . From there, the doctor can indicate which areas to look for in the next steps.

I have Turner. Can I only get pregnant with egg donation?

A visit to a gynecologist is recommended to make sure of this. The vast majority of patients with Turner syndrome are infertile, but between 2% and 5% of them are able to become pregnant spontaneously. However, it is important to remember that the pregnancy of a woman with Turner syndrome is often at risk, so care is recommended.

Turner syndrome is a rare genetic disease that is not passed down from generation to generation and can cause several complications and must be followed up by a doctor. Share this text with your friends so they can learn a little about it!

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