Syndrome, fragile X
The most common heritable form of mental retardation, occurring in about one in two thousand males and a smaller percentage of females. Characteristics of Fragile X syndrome in boys include prominent or long ears, a long face, delayed speech, large testes (macroorchidism), hyperactivity, tactile defensiveness, gross motor delays, and autistic-like behaviors. Much less is known about girls with Fragile X syndrome. Only about half of all females who carry the genetic mutation have symptoms themselves. Of those, half are of normal intelligence, and only one-fourth have an IQ under seventy. Few Fragile X girls have autistic symptoms, although they tend to be shy and quiet. Fragile X syndrome is due to a dynamic mutation (a trinucleotide repeat) at an inherited fragile site on the X chromosome, and so is an X-linked disorder. Because the mutation is dynamic, it can change in length and hence in severity from generation to generation, from person to person, and even within a given person. Fragile X syndrome is diagnosed with a genetic test. Also known as FRAXA (as is the Fragile X chromosome itself) and Martin-Bell syndrome.

Medical dictionary. 2011.

Look at other dictionaries:

  • Syndrome Fra-X — Syndrome de l X fragile Syndrome de l X fragile Autre nom Syndrome de Martin Bell Référence MIM …   Wikipédia en Français

  • Fragile X syndrome — Classification and external resources Location of FMR1 gene ICD 10 Q99.2 …   Wikipedia

  • Syndrome du X fragile — Syndrome de l X fragile Syndrome de l X fragile Autre nom Syndrome de Martin Bell Référence MIM …   Wikipédia en Français

  • Fragile-X-Mental-Retardation-1-Protein — Masse/Länge Primärstruktur 632 Aminosäuren …   Deutsch Wikipedia

  • fragile X syndrome — fragile X syndrome. См. синдром Мартина Белл. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Fragile X syndrome — One of the most common causes of inherited mental retardation and neuropsychiatric disease in human beings, affects as many as one in 2000 males and one in 4000 females. The syndrome is also known as FRAXA (the fragile X chromosome itself) and as …   Medical dictionary

  • fragile-X syndrome — ▪ chromosomal disorder       a chromosomal disorder associated with a fragile site on the end of the X chromosome. The major symptom of the syndrome is diminished mental ability, which may range from mild learning impairment to severe… …   Universalium

  • Fragile X chromosome — An X chromosome with a heritable fragile site associated with a frequent form of mental retardation the fragile X syndrome. The fragile X chromosome was first sighted by Dr. Herbert A. Lubs in 1969 who termed it the marker X. . The fragile X is… …   Medical dictionary

  • Fragile X Mental Retardation 1 — Das Fragile X Mental Retardation 1 (FMR1; Fragile X Mental Retardation 1) ist ein Gen. Sein Produkt ist das Fragile X Mental Retardation Protein (FMRP). Dabei handelt es sich um ein selektiv RNA bindendes Protein, das im adulten Organismus… …   Deutsch Wikipedia

  • Fragile X Mental Retardation Protein — Das Fragile X Mental Retardation 1 (FMR1; Fragile X Mental Retardation 1) ist ein Gen. Sein Produkt ist das Fragile X Mental Retardation Protein (FMRP). Dabei handelt es sich um ein selektiv RNA bindendes Protein, das im adulten Organismus… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”