As teens, XXY males may develop breast tissue and also have weaker bones, and a lower energy level than other males.By adulthood, XXY males look similar to males without the condition, although they are often taller. In adults, possible characteristics vary widely and include little to no sign of affectedness, a lanky, youthful build and facial appearance, or a rounded body type with some degree of gynecomastia (increased breast tissue). Gynecomastia is present in about a third of affected individuals, a slightly higher percentage than in the XY population. About 10% of XXY males have gynecomastia noticeable enough that they may choose to have cosmetic surgery.Affected males are often infertile, or have reduced fertility. Advanced reproductive assistance is sometimes possible. An estimated 50% of males with Klinefelter syndrome can produce sperm.The term "hypogonadism" in XXY symptoms is often misinterpreted to mean "small testicles", when it instead means decreased testicular hormone/endocrine function. Because of (primary) hypogonadism, individuals often have a low serum testosterone level, but high serum follicle-stimulating hormone and luteinizing hormone levels, hypergonadotropic hypogonadism. Despite this misunderstanding of the term, however, XXY men may also have microorchidism (i.e., small testicles).The testicles of affected males are usually less than 2 cm in length (and always shorter than 3.5 cm), 1 cm in width, and 4 ml in volume.XXY males are more likely than other men to have certain health problems, such as autoimmune disorders, breast cancer, venous thromboembolic disease, and osteoporosis.
If gynecomastia is present, the surgical removal of the breast may be considered for both the psychological reasons and to reduce the risk of breast cancer.The use of behavioral therapy can mitigate any language disorders, difficulties at school, and socialization. An approach by occupational therapy is useful in children, especially those who have dyspraxia. Infertility treatment
Methods of reproductive medicine, such as intracytoplasmic sperm injection (ICSI) with previously conducted testicular sperm extraction (TESE), have led to men with Klinefelter syndrome producing biological offspring. By 2010, over 100 successful pregnancies have been reported using IVF technology with surgically removed sperm material from males with KS. Prognosis
The lifespan of individuals with Klinefelter syndrome appears to be reduced by around 2.1 years compared to the general male population. These results are still questioned data, are not absolute, and need further testing. Epidemiology
This syndrome, evenly distributed in all ethnic groups, has a prevalence of approximately four subjects per every 10,000 (0.04%) males in the general population. However, it is estimated that only 25% of the individuals with Klinefelter syndrome are diagnosed throughout their lives. The rate of Klinefelter syndrome among infertile males is 3.1%. The syndrome is also the main cause of male hypogonadism. History
The syndrome was named after American endocrinologist Harry Klinefelter, who in 1942 worked with Fuller Albright and E. C. Reifenstein at Massachusetts General Hospital in Boston, Massachusetts, and first described it in the same year.