Other Names for this Disease
- 48 XXXX
- 48 XXXX syndrome
- 48,XXXX syndrome
- Quadruple X
- Tetra X
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X chromosome instead of two. Females with tetrasomy X have a total of 48 chromosomes in their cells, so this condition is sometimes written as 48, XXXX. The signs and symptoms of tetrasomy X vary, but can include mild to moderate speech and learning difficulties; developmental delay; distinctive facial features; dental abnormalities; hypotonia and joint laxity; radioulnar synostosis; heart defects; hip dysplasia; and problems with ovarian function. An increased risk of childhood infections has also been reported. Tetrasomy X is caused by a random error that occurs during the development of an egg cell and is not caused by anything a mother does during her pregnancy.Tetrasomy X is a chromosome disorder that only affects females and is caused by having four copies of the
Last updated: 2/19/2014
- Tetrasomy X. Unique. 2005; http://www.rarechromo.org/information/Chromosome_X/Tetrasomy_X%20FTNW.pdf. Accessed 9/11/2012.
- N Ayari, A Berge, Susan Howell, and Nicole Tartaglia. Tetrasomy X. Orphanet. January, 2010; http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=390. Accessed 2/19/2014.
- Genetics Home Reference (GHR) contains information on Tetrasomy X. This website is maintained by the National Library of Medicine.
- Unique is a source of information and support to families and individuals affected by rare chromosome disorders. Click on the link to view information about tetrasomy X.