The term Klinefelter syndrome KS describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in males. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48,XXYY and 48,XXXY being present in 1 per 17, to 1 per 50, male births. In addition, 46,XX males also exist and it is caused by translocation of Y material including sex determining region SRY to the X chromosome during paternal meiosis. Formal cytogenetic analysis is necessary to make a definite diagnosis, and more obvious differences in physical features tend to be associated with increasing numbers of sex chromosomes. If the diagnosis is not made prenatally, 47,XXY males may present with a variety of subtle clinical signs that are age-related.
Klinefelter syndrome and other sex chromosomal aneuploidies
Klinefelter syndrome - Wikipedia
Klinefelter syndrome KS , also known as 47,XXY is the set of symptoms that result from two or more X chromosomes in males. Klinefelter syndrome occurs randomly. While no cure is known, a number of treatments may help. Klinefelter syndrome is one of the most common chromosomal disorders , occurring in one to two per 1, live male births. The primary features are infertility and small poorly functioning testicles.
Klinefelter syndrome is a chromosomal condition in boys and men that can affect physical and intellectual development. Most commonly, affected individuals are taller than average are unable to father biological children infertile ; however the signs and symptoms of Klinefelter syndrome vary among boys and men with this condition. In some cases, the features of the condition are so mild that the condition is not diagnosed until puberty or adulthood, and researchers believe that up to 75 percent of affected men and boys are never diagnosed.
Klinefelter syndrome is a fairly common genetic condition found in males only. Many boys with Klinefelter syndrome — also known as XXY syndrome — have no signs or symptoms, and some don't even know they have it until later in life. The XXY condition that causes Klinefelter syndrome can't be changed, but medical treatment and working with therapists can help a boy's development and help lessen the condition's effects.