Klinefelter syndrome is the name for a maldistribution of sex chromosomes. It exclusively affects males and is characterized by a supernumerary X chromosome. The expression of the symptoms is very variable. Therefore, treatment is not necessary in all cases when Klinefelter syndrome occurs.
What is Klinefelter syndrome?
Klinefelter syndrome is a hereditary constitution based on chromosomal maldistribution, and patients are exclusively males. The nuclei of affected individuals have a redundant X chromosome, thus possessing 2, rather than a single X chromosome. Cases with 3 or 4 X chromosomes of unknown origin are also described in the literature. The X chromosome is the female element in sex determination. Klinefelter syndrome belongs to the phenomenon of chromosomal aberration or aneuploidy, as deviations from the average constellation are also called. The term of this genetic variation, sometimes also called hereditary disease, goes back to the US-American physician Harry Fitch Klinefelter (1912 – 1990), who worked in Baltimore as an associate professor of medicine. He was the first to describe Klinefelter syndrome, subsequently named after him, in 1942.
Causes
Klinefelter syndrome causally arises during germ cell development. The time of the occurring defect is the maturation division (meiosis), during which the double set of chromosomes is halved. In this process, it can happen that an X chromosome does not reach its target cell in a physiogenetically “correct” way, but remains behind. This results in a germ cell with an excess X chromosome. Both the oocytes and the sperm, which contribute the Y chromosome in the sex determination to the male, can be affected. Normogenetic oocytes have 1 X chromosome, normogenetic sperm have either 1 X or 1 Y chromosome. The “Klinefelter oocytes” have the constellation XX, rarely also XXX or XXXX. The “Klinefelter spermatozoa” have the following set of sex chromosomes: XY, XXY or XXXY. After the egg and sperm fuse, the composition results in XXY (rarely also XXXY or XXXXY) and lead to Klinefelter syndrome.
Symptoms, complaints, and signs
The symptoms of Klinefelter syndrome often cannot be noticed until puberty. Before then, they are usually very mild. The main symptoms of the condition are underdeveloped testes and a strikingly low testosterone level. The sex hormone testosterone triggers puberty in healthy boys and ensures that the secondary sexual characteristics develop. If there is a deficiency, these developments do not occur or proceed much more slowly than in adolescents of the same age. A prominent symptom is also infertility. Depending on the severity, the onset of puberty may be severely delayed. Affected individuals usually have only sparse or no male body hair. Beard growth is absent. The voice pitch of adolescents with Klinefelter syndrome is high and hardly changes. In late puberty, there may be excessive breast development. The penis is noticeably small. Sometimes there is undescended testis. In general, affected individuals tend to have a low libido. Symptoms often include tall stature, osteoporosis, decreased bone density, scoliosis, low muscle tone, fatigue, or anemia. In childhood, some affected individuals have cognitive impairments, delayed language development, or motor function problems. As a result, learning difficulties may occur later. In addition, affected individuals often experience dental problems such as malocclusions or tooth decay.
Diagnosis and course
In Klinefelter syndrome, the testes do not develop to the usual extent. This, known as “hypogonadism,” also results in insufficient secretion of the hormones that determine masculinity. This tends to result in the expression of secondary sexual characteristics that are usually attributed to women. Increased growth of the breasts as well as a wider pelvis and little body hair are characteristics of affected men. In most cases, they are also incapable of procreation, although there are no disturbances in their sexual life. The symptoms are sometimes more, sometimes less pronounced, sometimes so discrete that there is never a diagnosis or treatment.If Klinefelter syndrome is suspected during adolescence, the physician will arrange for a light microscopic chromosome count. This will also reveal whether one of the rare “mosaic cases” is present, the causes of which are unknown. “Mosaic types” are called these variants because only parts of the body are affected by the chromosomal abnormality. The result is an incompletely expressed Klinefelter syndrome.
Complications
Klinefelter syndrome can cause various symptoms and complications in the patient. However, in most cases, there is a severe tall stature, which mainly affects the legs and arms. The muscles of the affected person are also weakened, so that the patient is less able to bear weight. This can also negatively affect the development of the child. Motor development is also delayed, so that the affected person may be dependent on the help of other people in everyday life. It is not uncommon for patients to be irritable and suffer from severe mood swings. These can have a negative effect on the social environment, leading to severe discomfort. Infertility also occurs and the man is unable to procreate. The men also suffer from only very slightly pronounced beard growth, which can lead to inferiority complexes or lowered self-esteem. Klinefelter syndrome is often associated with psychological symptoms. Treatment of Klinefelter syndrome takes place with the help of various therapies, although not all complaints can be limited. It is usually impossible to predict whether there will be a reduction in life expectancy.
When should you see a doctor?
If there is a suspicion that the child suffers from Klinefelter syndrome, a doctor should be consulted. Symptoms such as tall stature, muscle weakness and small testicles indicate a serious condition that needs to be diagnosed. The physician can determine whether Klinefelter syndrome underlies the signs and, if necessary, initiate treatment directly. Early therapy is essential to avoid a severe course with permanent damage. For this reason, all abnormalities should be clarified quickly, especially visible malformations or behavioral abnormalities. Children who withdraw from social life or are unusually irritable require medical and therapeutic treatment. The individual symptoms can usually be treated well, provided they are recognized and treated at an early stage. If psychological symptoms have already developed, treatment by a psychologist is indicated. Therapeutic support is also useful for the parents, as the disease can be an enormous burden in the long term. The right contact person is the family doctor or a specialist clinic for genetic diseases.
Treatment and therapy
Men affected by Klinefelter syndrome usually suffer the most from the consequences of testosterone deficiency. The “male” hormone is therefore supplemented with medication in some patients. The physician must also take into account that Klinefelter’s syndrome also frequently leads to diabetes mellitus. If necessary, he will initiate an appropriate diet or also take medicinal action. Osteoporosis is another complication of Klinefelter syndrome. The consequences of the “softening of the bones” must be addressed by the orthopedist. The delayed development of speech, which is diagnosed in some of those affected, can be compensated for by early remedial teaching. Psychological issues are also relevant in relation to Klinefelter syndrome. This is because some affected individuals suffer from a disturbed sense of identity with regard to their gender role. A psychotherapist can provide suitable help here. Social discrimination is expressed, for example, in some portrayals even in the specialist literature. There, a reduction in intelligence is still attributed to Klinefelter syndrome, which is not the case according to more recent studies. Here educational work is demanded for the dismantling of prejudices in relation to the Klinefelter syndrome.
Outlook and prognosis
Klinefelter syndrome occurs exclusively in individuals of the male sex. Because it is a disorder of chromosomes, there is no cure for the condition. Patients face a
long-term therapy in order to achieve relief from the symptoms. The affected person is found to have a deficiency of the hormone testosterone.This must be balanced over the entire lifespan in order for the symptoms to be alleviated. As soon as the hormone therapy used is discontinued on one’s own responsibility, a relapse of the symptoms is to be expected. If the administration of the hormone can be successfully implemented on a permanent basis, patients often report freedom from symptoms. Due to the syndrome, a secondary disease is usually diagnosed. This usually has a chronic course. In determining the prognosis, the secondary disorders must be taken into account. They worsen the overall condition and lead to an increased burden for the affected person. In addition to the physical impairments, emotional and mental stress is to be expected. This can have a negative impact on the patient’s general well-being and thus further worsen the patient’s health. In severe cases, psychological disorders develop as a result of Klinefelter syndrome. If therapy is used, in most cases there is an improvement in the quality of life. Nevertheless, many patients refuse to seek psychotherapy.
Prevention
Klinefelter syndrome cannot be effectively prevented because of its genetic causality. At most, couples who wish to have children should keep in mind that aneuploidies increase with increasing age of the mother. This is also detectable in Klinefelter syndrome.
Follow-up
As a rule, there are no special or direct options for aftercare available to the patient in Klinefelter syndrome, so that early diagnosis with subsequent treatment should take place in the first instance in this disease. There can be no self-healing, and a complete cure is usually not possible either. Therefore, if the patient wishes to have children, genetic testing and counseling should always be performed first in order to prevent the recurrence of the syndrome. The symptoms themselves are usually alleviated with the help of medication. Care must be taken to ensure that the correct dosage is taken and that it is taken regularly. In the case of children, parents should check that the medication is being taken correctly. Likewise, a doctor can set up a diet plan to counteract the symptoms of Klinefelter syndrome. This plan should be followed, and a healthy lifestyle with a balanced diet will have a positive effect on the further course of the disease. Most of those affected also need psychological support. In this context, loving and intensive discussions with parents and relatives have an equally positive effect on the psychological state of the affected person. As a rule, Klinefelter syndrome does not reduce the life expectancy of the affected person.
What you can do yourself
In Klinefelter syndrome, the possibilities of self-healing are severely limited. For this reason, affected individuals are primarily dependent on medical treatment to avoid further complications and discomfort. Since the disease in many cases significantly increases the risk of diabetes, attention should be paid to a healthy lifestyle with a healthy diet and plenty of exercise. The respective diet can be prescribed by a physician or by a nutritionist. Due to osteoporosis occurring, exercise should be done in moderation and with caution. The slowed speech development can also be alleviated by various trainings. Here, especially the parents must show initiative and can also promote this development with various exercises at home. The psychological symptoms of Klinefelter syndrome do not always have to be treated immediately by a psychologist. Often conversations with other affected persons or with the closest friends or with the family help. Inferiority complexes can also be alleviated in this way. Due to the reduction in intelligence, those affected are dependent on intensive and loving care. Especially the care of close people has a very positive effect on the course of the disease.
