Why is klinefelters syndrome not hereditary

The signs and symptoms of Klinefelter syndrome KS vary among affected people. Some men with KS have no symptoms of the condition or are only mildy affected. In these cases, they may not even know that they are affected by KS. In these cases, known as "variants of Klinefelter syndrome", the signs and symptoms can be more severe and may include: [1] [2] [4] Intellectual disability Distinctive facial features Skeletal abnormalities Poor coordination Severe speech difficulties Behavioral problems Heart defects Teeth problems.

Cause Cause. Klinefelter syndrome usually occurs as a random event during the formation of reproductive cells eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain one or more extra copies of the X chromosome as a result of nondisjunction.

If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have one or more extra X chromosomes in each of the body's cells. Some people with Klinefelter syndrome have the extra X chromosome in only some of their cells; these people are said to have mosaic Klinefelter syndrome. Women who have pregnancies after age 35 have a slightly increased chance of having offspring with this syndrome. Inheritance Inheritance. Klinefelter syndrome is not inherited , but usually occurs as a random event during the formation of reproductive cells eggs and sperm.

An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. If one of these reproductive cells contributes to the genetic makeup of a child, the child will have one or several extra X chromosomes in each of the body's cells. Diagnosis Diagnosis. A diagnosis of Klinefelter syndrome is often suspected based on the presence of characteristic signs and symptoms. Additional testing can then be ordered to confirm the diagnosis.

This generally includes a chromosomal analysis called a karyotype. Treatment Treatment. Because symptoms of Klinefelter syndrome KS can sometimes be very mild, many people are never diagnosed or treated. When a diagnosis is made, treatment is based on the signs and symptoms present in each person, especially the problems related to hypogonadism , gynecomastia , and psychosocial problems. Treatment may include: [1] [3] [4] Testosterone replacement: About half of people with SK have low testosterone levels, which may be raised by taking supplemental testosterone.

Having a more normal testosterone level can help affected people develop bigger muscles, a deeper voice, and facial and body hair, and may also increase sexual desire, enlarge the testes , improve mood, self-image, and behavior; it may also protect against osteoporosis and decrease the risks of autoimmune disease and breast cancer.

Breast removal or reduction surgery. Educational interventions: As children, many people with Klinefelter syndrome qualify for special services to help them in school. Teachers can also help by using certain methods in the classroom, such as breaking bigger tasks into small steps.

Several forms of therapy such as physical, speech, occupational, behavioral, mental health, and family therapy can often help reduce or eliminate some of the symptoms of Klinefelter syndrome such as poor muscle tone; speech and language problems; or low self-confidence. Prognosis Prognosis. Babies with the 47, XXY form of Klinefelter differ little from healthy children.

The results of one study on non- mosaic XXY infants younger than 2 years indicated that most XXY babies had normal external genitalia and facial features with height and weight in the normal range.

Early diagnosis of Klinefelter syndrome is shown to be important to monitor potential developmental problems. However, most move toward full independence from their families as they enter adulthood. Some have completed graduate education and have a normal level of functioning.

Lifespan is not affected by Klinefelter syndrome. Statistics Statistics. It is estimated that 1 in every to 1, newborn males has an extra X chromosome, making Klinefelter syndrome one of the most common chromosomal disorders seen among newborns. In addition, the features of this condition vary and can overlap significantly with those of other conditions. Do you have updated information on this disease? We want to hear from you.

Research Research. Klinefelter syndrome occurse due to a random event when the reproductive cells eggs and sperm are forming in the parent. The random event is called nondisjunction and the resulting reproductive cell has an abnormal number of chromosomes. Nondisjunction is often associated with increased maternal age [1].

Mosaic Klinefelter syndrome results from a random event in cell division early in fetal development. As a result- there are two cell lines within the body. Individuals with mosaic Klinefelter may have less severe signs and symptoms. The signs and symptoms of individuals with Klinefelter syndrome 47,XXY and its variants tend to vary among affected individuals [2]. The following are characteristic of Klinefelter syndrome:. There is also an increased risk for breast cancer and systemic lupus erythematosus.

Individuals with variants of Klinefelter more than one extra chromosome, like 48,XXXY and 49,XXXXY may have intellectual disabilities, distinctive facial features, skeletal abnormalities, poor coordination, and severe speech problems. As the number of extra sex chromosomes increases, so does the risk of developing these more severe health problems [2]. Individuals with Klinefelter syndrome typically have microorchidism small testes and do not produce adequate levels of testosterone.

Testosterone directs male sexual development before birth and during puberty. A shortage of testosterone can lead to delayed or incomplete puberty, gynecomastia, reduced facial and body hair, and infertility [2]. Fertility preservation may be best proposed to adolescent Klinefelter patients, just after the onset of puberty, when it is possible to collect a semen sample and when the patient is able to consider alternative options to achieve fatherhood and also accept the failure of spermatozoa or immature germ cell retrieval [5].

Additionally, successful sperm retrieval may decrease with age and after testosterone therapy, further warranting fertility preservation during adolesence [3]. The following are methods for preserving fertility in those with Klinefelter syndrome:.

TESE invovles extracting viable sperm cells from testicular tissue after a testicular biopsy. Pening et al. TESE can be combined with itracytoplasmic sperm injection ICSI and in vitro fertilization IVF ; it offers the opportunity for Klinefelter patients with azoospermia to father children with their own spermatozoa.

However, successful retrieval decreases with age and after testosterone therapy [3] , therefore it is important to discuss the option of TESE with adolescents or quickly after diagnosis of Klinefelter syndrome in adult men. Germ cell depletion begins at the onset of puberty and leads to infertility, therefore banking SSCs, also called immature germ cells, has been proposed as a strategy to preserve fertility in adolescents with Klinefelters syndrome. For optimal preservation of SSCs, spermatogonia should be retrieved by testicular biopsy preferably before the testis hyalinization occurs [8].

For those without azoospermia or before undergoing testosterone replacement therapy, sperm cells may be collected after ejaculation and frozen for future use. This may be a better option for those men with mosaic Klinefelter syndrome, as most men with Klinefelter have azoospermia. Read more information about sperm banking. While Klinefelter syndrome is genetic, in that it involves one or more extra X chromosome gene, it is not usually hereditary in the conventional sense. That is, Klinefelter syndrome is not inherited, nor does it "run in families.

Klinefelter syndrome research scientists are not sure what puts a couple at risk for conceiving a child with Klinefelter syndrome.

Advanced maternal age increases the risk for the XXY chromosome count, but only slightly. Furthermore, recent Klinefelter syndrome research shows that half the time, the extra chromosome comes from the father. Click Genetic Cause of Klinefelter Syndrome for more information on genetics and Klinefelter syndrome.

Last reviewed by: Arthur Schoenstadt , MD. Genetic Cause of Klinefelter Syndrome. Is Klinefelter Syndrome Hereditary? Diagnosing Klinefelter Syndrome. Treatments for Klinefelter Syndrome. Medical Problems of Klinefelter Syndrome. Prognosis of Klinefelter Syndrome. Research on Klinefelter Syndrome.