Instituto Valenciano de Microbiología
(IVAMI)

Masía El Romeral
Ctra. de Bétera a San Antonio Km. 0.3
46117 Bétera (Valencia)
Phone. 96 169 17 02
Fax 96 169 16 37
Email: 
www.ivami.com
CIF B-96337217

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Triple X syndrome ... (Triple X syndrome) - Chromosome X.

Triple X syndrome, Trisomy X or also called 47, XXX, is characterized by the presence of an extra chromosome X in each of the cells of a woman. Although women affected may be higher than average, this chromosomal change usually causes no unusual physical characteristics. Most women with triple X syndrome have normal sexual development and are fertile. Triple X syndrome is associated with an increased risk of learning disabilities and delayed development of speech and language skills. The delayed development of motor skills, hypotonia, and emotional and behavioral problems are also possible, but these characteristics vary widely among girls and women affected. In addition, seizures or kidney abnormalities occur in approximately 10% of women affected.

Normally, people have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, help determine whether a person will develop characteristics of male or female sex. Women normally have two X (46, XX) chromosomes and males have one X chromosome and one Y chromosome (46, XY). Triple X syndrome is due to an extra copy of the X chromosome in each cell of a woman. As a result of additional X chromosome, each cell has a total of 47 chromosomes (47, XXX) instead of the usual 46. An extra copy of the X chromosome is associated with tall stature, learning disabilities, and other features in some girls and women. Some women with triple X syndrome have an extra X chromosome in only some of their cells. This phenomenon is called mosaicism 46, XX / 47, XXX. As the number of additional sex chromosomes increases, so it does the risk of learning disabilities, mental retardation, birth defects and other health problems.

Most cases of triple X syndrome are not inherited. Chromosomal change generally occurs as a random event during the formation of reproductive cells. An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. For example, a reproductive cell can get an extra copy of chromosome X as a result of non - disjunction. If one of these atypical reproductive cells contributes to the genetic composition of a child, the child will have an extra chromosome X in each of the cells of the organism. Mosaicism 46, XX / 47, XXX is not inherited. It appears as a random event during cell division in early embryonic development. As a result, some of the cells of an affected individual has two X chromosomes (46, XX), and other cells have three X chromosomes (47, XXX).

Tests in IVAMI: in IVAMI perform detection of mutations associated with triple X syndrome, through the detection of additional X chromosomes.

Samples recommended: EDTA blood collected for separation of blood leukocytes.