Triple X syndrome is a form of chromosomal variation characterized by the presence of an extra X chromosome in each cell of a human female. The condition is also known as triplo-X, trisomy X, XXX syndrome, and 47,XXX aneuploidy. Triple X results during division of a parent's reproductive cells. Females (about 0.1 % of all females) with the condition are not at any increased risk for medical problems. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... // Q00-Q99 - Congenital malformations, deformations and chromosomal abnormalities (Q00-Q07) Congenital malformations of the nervous system (Q00) Anencephaly and similar malformations (Q01) Encephalocele (Q02) Microcephaly (Q03) Congenital hydrocephalus (Q04) Other congenital malformations of brain (Q05) Spina bifida (Q06) Other congenital malformations of spinal cord (Q07) Other congenital malformations of nervous... The Disease Bold textDatabase is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals (the other is the Y chromosome). ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ...

Symptoms

Due to the lyonization, inactivation and formation of a Barr body in all female cells, only one X chromosome is active at any time in a female cell. Thus, triple X syndrome most often causes no unusual physical features or medical problems. Females with the condition are usually taller than average, and their weight may be low in comparison to their height. They may have menstrual irregularities, and, although rarely exhibiting severe mental impairments, sometimes have an increased risk of learning disabilities and delayed speech and language skills. The Lyon hypothesis states that in cells with multiple X chromosomes, all but one is inactivated during mammalian embryogenesis. ... In those species in which sex is determined by the presence of the Y or W chromosome rather than the diploidy of the X or Z, a Barr body is the inactive X chromosome in a female cell, or the inactive Z in a male (Lyon, 2003), rendered inactive in... Menstrual cycle The menstrual cycle is a recurring cycle of physiological changes in the females of some animal species that is associated with reproductive fertility. ... Mental retardation is a term for a pattern of persistently slow learning of basic motor and language skills (milestones) during childhood, and a significantly below-normal global intellectual capacity as an adult. ... In the United States and Canada, the term learning disability is used to refer to psychological and neurological conditions that affect a persons communicative capacities and potential to be taught effectively. ...

A similar range of body types and characteristics are present in both triple X and Klinefelter's syndrome. These include a lanky/youthful appearance, non-affectedness, or varying degrees of androgyny. Body types/characteristics often follow traits shown in family members who are unaffected. The additional X chromosome can come from either the maternal or paternal side. Although body types and characteristics are distinguishable in triple X, the condition is verified only by karyotype testing. Klinefelters syndrome, 47XXY or XXY syndrome is a condition caused by a chromosome nondisjunction in males; affected individuals have a pair of X sex chromosomes instead of just one and are at additional risk for some medical conditions. ... This article or section does not adequately cite its references or sources. ... Karyogram of human male using Giemsa staining. ...

Most women with triple X have normal sexual development and are able to conceive children. A few may experience early onset of menstruation. This article or section does not adequately cite its references or sources. ... A sperm cell fertilising an ovum This article is about reproduction in organisms. ... Menstrual cycle. ...

Triple X women are rarely diagnosed apart from pre-natal testing methods, such as amniocentesis. Most medical professionals do not regard the condition a disability, however such status can be sought by parents for early intervention treatment if mild delays are present. Amniocentesis, or an Amniotic Fluid Test (AFT), is a medical procedure used for prenatal diagnosis, in which a small amount of amniotic fluid is extracted from the amnion around a developing fetus. ... Look up disability in Wiktionary, the free dictionary. ...

Cause

Triple X syndrome is not inherited, but usually occurs as a random event during the formation of reproductive cells (ovum and sperm). An error in cell division called nondisjunction can result in reproductive cells with additional chromosomes. For example, an oocyte or sperm cell may gain an extra copy of the X chromosome as a result of the nondisjunction. If one of these cells contributes to the genetic makeup of a child, the child will have an extra X chromosome in each of his or her cells. In some cases, trisomy X occurs during cell division in early embryonic development. Gametes (in Greek: γαμέτες) —also known as sex cells, germ cells, or spores—are the specialized cells that come together during fertilization (conception) in organisms that reproduce sexually. ... A human ovum Sperm cells attempting to fertilize an ovum An ovum (plural ova) is a haploid female reproductive cell or gamete. ... A spermatozoon or spermatozoan ( spermatozoa), from the ancient Greek σπέρμα (seed) and (living being) and more commonly known as a sperm cell, is the haploid cell that is the male gamete. ... Nondisjunction is the failure of homologous chromosomes to properly segregate during meiotic or mitotic anaphase, resulting in daughter cells with abnormal numbers of chromosomes. ... An oocyte or ovocyte is a female gametocyte or germ cell involved in reproduction. ... It has been suggested that embryology be merged into this article or section. ...

Some females with triple X syndrome have an extra X chromosome in only some of their cells. These cases are called 46,XX/47,XXX mosaics. In medicine (genetics), a mosaic or mosaicism denotes the presence of two populations of cells with different genotypes in one patient, where usually one of the two is affected by a genetic disorder. ...

Incidence

Triple X syndrome occurs in 1 in 1000 newborn girls. Five to ten girls with triple X syndrome are born in the United States each day.

First case

The first published report of a woman with a 47,XXX karyotype was by Patricia A. Jacobs, et al. at Western General Hospital in Edinburgh, Scotland in 1959. It was found in a 35-year-old, 5 ft. 9 in. [176 cm] tall, 128 lb. [58.2 kg] woman who had premature ovarian failure at age 19; her mother was age 41 and her father was 40 at the time of her conception.^[1] The Western General is one of the main teaching hospitals affiliated to the University of Edinburgh Medical School. ... Edinburgh viewed from Arthurs Seat. ... Premature Ovarian Failure (POF) is the cessation of menstrual periods and ovulation in women under the age of 40. ...

See also

• Klinefelter syndrome
• XYY syndrome
• Turner syndrome
• XXXX syndrome
• XXXXX syndrome

XXY karyotype Klinefelters syndrome is a condition caused by a chromosome abnormality in males (specifically, a nondisjunction); sufferers have a pair of X sex chromosomes instead of just one. ... XYY syndrome is an aneuploidy (specifically a trisomy) of the sex chromosomes in which a human male receives an extra Y chromosome, producing a 47,XYY karyotype. ... XXXX syndrome (also called tetrasomy X) is the presence of two additional X chromosomes. ... XXXXX syndrome (also called pentasomy X) is the presence of three additional X chromosomes. ...

References

External links

• Klinefelter Syndrome & Associates (http://www.genetic.org/)
• Overview of condition, Genetics Home Reference at NLM
• Booklet from the Turner Center in Denmark
• Community
  • Children & Infants
  • Teens & Adults
• Triple X Syndrome symptoms