Fragile X Syndrome
Fragile X syndrome is the most common form of heritable mental retardation affecting approximately 1 in 1,250 males and 1 in 2,000 females (Webb 1989). The prevalence appears to be 1 in 4,000–6,000 males and 1 in 8,000–10,000 females. Martin and Bell first documented X-linked mental retardation in 1943. Subsequent identification of a fragile site on the long arm of the X chromosome (Lubs 1969), discovery of cell culture medium-dependent fragile site, and recognition of a unique constellation of physical features served to distinguish fragile X syndrome from other X-linked mental retardation syndromes.
In Verkerk et al. (1991) identified a single gene that was associated with symptoms of the disorder. The gene, known as fragile X mental retardation gene 1 (FMR1), exhibited a novel form of mutation, a sequence of three nucleotides (CGG) that was repeated many times in patients with fragile X syndrome.
Synonyms and Related Disorders
Fragile X mental retardation syndrome; Marker X...
KeywordsMental Retardation Mitral Valve Prolapse Repeat Size Full Mutation Premutation Carrier
- American Academy of Pediatrics. (1996). Health supervision for children with fragile X syndrome. Pediatrics, 98, 297–300.Google Scholar
- Davids, J. R., Hagerman, R. J., & Eilert, R. E. (1990). Orthopaedic aspects of fragile-X syndrome. Journal of Bone and Joint Surgery (America), 72, 889–896.Google Scholar
- Dykens, E. M., Hodapp, R. M., & Leckman, J. F. (1994). Behavior and development in Fragile X syndrome. Thousand Oaks: Sage.Google Scholar
- Goldson, E., & Hagerman, R. J. (1992). The fragile X syndrome. Developmental Medicine and Child Neurology, 34, 822–832.Google Scholar
- Hagerman, R. J. (2001). Fragile X syndrome. In S. B. Cassidy & J. E. Allanson (Eds.), Management of genetic syndromes. New York: Wiley-Liss.Google Scholar
- Hagerman, R. J., & Cronister, A. (Eds.). (1996). Fragile X syndrome: Diagnosis, Treatment, and Research. Baltimore: Johns Hopkins University Press.Google Scholar
- Hagerman, R. J., Kimbro, L. T., & Taylor, A. K. (1998). Fragile X syndrome: A common cause of mental retardation and premature menopause. Contemporary OB/GYN, 43, 47–70.Google Scholar
- Hagerman, R. J., & Silverman, A. C. (1991). Fragile X syndrome. Diagnosis, treatment, and research. Baltimore: Johns Hopkins University Press.Google Scholar
- Nelson, D. L. (1993). Fragile X syndrome: Review and current status. Growth Genetics Hormone, 9, 1–4.Google Scholar
- Noline, S. L., Lewis, F. A., II, Ye, L. L., et al. (1996). Familial transmission of the FMR1 CGG repeat. American Journal of Human Genetics, 59, 1252–1261.Google Scholar
- Saul, R. A., Tarleton, J. C. (2010). FMR1-related disorders. GeneReviews. Updated May 18, 2010. Available at: http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=fragilex
- Sutherland, G. R., Gecz, J., & Mulley, J. C. (2002). Fragile X syndrome and other causes of X-linked mental handicap. In D. L. Rimoin, J. M. Connor, R. E. Pyeritz, & B. R. Korf (Eds.), Principles and practice of medical genetics (4th ed., pp. 2801–2826). New York: Long Churchill Livingstone.Google Scholar
- Verkerk, A. J. M. H., Pieretti, M., Sutcliffe, J. S., et al. (1991). Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome. Cell, 65, 905–914.Google Scholar
- Warren, S. T., & Sherman, S. L. (2001). The fragile X syndrome. In C. R. Scriver, A. L. Beaudet, W. S. Sly, & D. Valle (Eds.), The metabolic and molecular bases of inherited disease (8th ed., pp. 1257–1289). New York: McGraw-Hill. Chapter 179.Google Scholar
- Webb, T. (1989). The epidemiology of the Fragile X syndrome. In K. E. Davis (Ed.), The Fragile X syndrome (pp. 40–55). Oxford: Oxford University Press.Google Scholar