What is 47,XXY / Klinefelter syndrome? When is one diagnosed? Does 47,XXY affect children and their Klinefelter syndrome, ,XXY, is a chromosomal condition Diagnosis can occur at any time in a person’s life. Th e char- development? that aff ects males. It is the leading cause of infertility and acteristics of 47,XXY are oft en subtle, so many XXY’s go No one can predict for certain what eff ect the extra hypogonadism. Every cell in the body contains  pairs of undiagnosed for years. Diagnosis is most likely to be made: chromosome will have on an individual. Personalities in chromosomes for a total of  chromosomes. Th e twenty- • as the result of prenatal testing this group are as varied as in the general population. In third pair, the sex chromosomes, are diff erent for males • during childhood when developmental delays in areas addition, the spectrum of manifestations is wide. and females. Females have two copies of the X chromo- like speech and language are present However, the following characteristics are said to occur some. Males have one X and one Y, or XY. In Klinefelter • at puberty when a boy’s secondary sexual characteristics more oft en in children with 47,XXY. Keep in mind that are not progressing in the typical way syndrome, males have an extra copy of the X chromo- a child may have only one or two features, while others some. Th e result is ,XXY in each cell. Some males are • during fertility studies, when a couple has been may have more: unsuccessful in conceiving a child ,XY/,XXY or mosaic, which means that some of their • delayed speech and in some instances cells have one X chromosome and one Y chromosome • gross and fi ne motor delays • if continuing physical or psychological diffi culties are (XY), while other cells have the extra X (XXY). Less com- • sensory integration diffi culties, which may include present mon variations result when there is more than one copy of sensitivity to things like sounds, touch, or movement the X or Y in each cell. Th ese variations include ,XXXY; Does 47,XXY affect one’s health? • mild hypotonia or low muscle tone ,XXYY; ,XXXXY; and ,XX males, which is termed XXY’s have an increased risk for: • ADHD sex-reversal syndrome. • autoimmune disorders, including diabetes and thyroiditis • auditory processing problems • language-based learning disabilities, including reading How common is this condition? • hypothyroidism and written language diffi culties ,XXY is estimated to occur in one out of  males, • breast cancer • social skill defi cits making it the most common chromosomal disorder. How- • osteoporosis • anxiety ever, the variations are far less common. Th e syndrome • leg ulcers • depression was named aft er physician, Dr. Harry Klinefelter, who • depression • gynecomastia or swelling of breast tissue during puberty published a report in  about nine men with enlarged • dental problems breast development, sparse facial and body hair, small Does 47,XXY affect fertility? Why is early diagnosis important? testes, and an inability to produce sperm. In the late ’s, Generally, XXY’s are infertile, but a semen analysis is sug- ,XXY is a leading cause of male infertility and testoster- other researchers found that the cause was due to an extra gested to be sure. Some 46,XY/47,XXY’s have preserved one defi ciency, yet the vast majority of KS individuals will X chromosome. Because all of the manifestations described testicular function. Recent advances in male infertility reach adulthood without diagnosis. by Dr. Klinefelter are not found in the majority of ,XXY treatment, such as testicular sperm extraction coupled with Early diagnosis means: males, the term ,XXY or XXY is preferred when referring in vitro fertilization and a procedure called ICSI (intracyto- • developmental delays can be addressed sooner to this condition. plasmic sperm insertion), can result in a full term pregnancy • appropriate educational interventions can be determined Is 47,XXY / Klinefelter syndrome inherited? without any chromosomal abnormalities. • hormone replacement can be timed appropriately No. It is a random event that happens when paired chromo- Other options for creating a family are donor insemination • having greater knowledge and understanding of one’s diagnosis somes fail to separate in the fi rst or second stage of meiosis. and adoption. • gaining better health management throughout life What causes 47,XXY? Th e exact cause of ,XXY is unknown, and the extra chro- An additional thought 47,XXY—THE EARLIER YEARS mosome can come from either parent. Current studies have shown that the diagnosis of Kline- felter syndrome does NOT indicate mental retardation, What does a 47,XXY newborn look like? How is 47,XXY diagnosed? deviant behavior, or other broad generalizations. Most ,XXY newborns look like any other newborn. Unless the Th e diagnosis is made by taking a blood sample which will individuals diagnosed with this condition have average to infant was tested prenatally, it is unlikely that anyone would provide a “karyotype” or photographic illustration of the superior intelligence with only about % scoring below suspect this condition. chromosomes in a single cell. average on standardized intelligence tests.