How Does Testosterone Treatment for Klinefelter's Syndrome Work?

Klinefelter Syndrome

Klinefelter Syndrome is a condition where a boy has an extra X chromosome in most of his cells. Traditionally a female has XX chromosomes and a male has XY chromosomes. Males with Klinefelter syndrome are XXY. The extra chromosome causes a boy to produce much less testosterone than an XY boy would. The decreased testosterone results in delayed puberty, less muscle mass, less body hair, smaller genitalia, infertility, breast growth, delayed motor development, language and reading difficulties, social shyness and decreased bone strength. Klinefelter Syndrome is a common condition, affecting an estimated 1 in 500 males, according to the American Association for Klinefelter Syndrome Information & Support.

Testosterone Treatment

Testosterone treatment should ideally begin around the time of puberty (usually 12 to 14 years old). Treatment can begin in the adult years as well, which is common since Klinefelter Syndrome usually remains undiagnosed until an adult man seeks fertility treatment. Testosterone treatment is given in the form of an injection, as an oral medication or as a topical preparation. The goal of testosterone treatment is to bring the male's testosterone levels to a normal level, which stimulates the development of masculine characteristics such as a deeper voice, facial and body hair, increased muscle growth and penis growth. The results are more effective when given at puberty, when the boy is still growing to prevent the growth of male breasts (a condition called gynecomastia), to promote bone strength and to stimulate increased muscle mass.

Fertility

While treatment with testosterone does increase the size of the penis, it does not increase the size of the testicles or make the male fertile. Between 95 to 99 percent of males with Klinefelter Syndrome, are infertile, according to the National Institute of Child Health and Development. Fertility treatments successfully help some men with Klinefelter Syndrome father children.

Combination Treatments

Testosterone therapy is sometimes combined with psychological counseling, special educational support and speech therapy for teenage boys to help them adjust to life emotionally, socially and educationally. Surgery is available for males who have gynecomastia, to remove excess breast tissue.

Prognosis

Males with Klinefelter Syndrome can and do live happy and normal lives. Many men with Klinefelter Syndrome have few or no symptoms and live out their entire lives without ever knowing they are XXY. For those males who have symptoms and are diagnosed as XXY, testosterone treatment and other therapies help reduce or the symptoms of the syndrome.