While many chromosomal disorders are genetic in nature, some, like Klinefelter syndrome, are not passed from parent to child. A randomly occurring disorder, Klinefelter syndrome is identified via a karyotype with the presence at least one extra X chromosome; symptoms are more impactful as the number of extra chromosomes increases. The symptoms of this disorder often manifest during puberty, but some individuals have such mild symptoms that they do not even realize they have the diagnosis. Though males with this disorder have a higher incidence of breast cancer than their peers, it is not as commonplace as in women. The life expectance of a person with Klinefelter syndrome is almost exactly that of the average male.
The primary symptoms are small testicles and infertility. However, other defining factors include poor coordination, decreased interest in sex, weaker muscles, less body hair, a greater height, and the development of breast tissue. While intelligence does not appear to be impacted, reading difficulties and speech problems are more likely in individuals with the disorder. Though it is not curable, many of the symptoms are treated relatively easily. Physical and speech therapy can address the problems with coordination and communication; counseling and other forms of emotional support can help one cope with the disorder. Though infertility is one of the defining symptoms, this can be overcome though reproductive therapies, though at a great financial cost. Though this disorder is relatively common - occurring in approximately 1 to 2 out of every 10,000 male births, it is not one that should have a profound impact on a person's quality of life.