Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 1998 Jul;35(7):579-89.
doi: 10.1136/jmg.35.7.579.

The fragile X syndrome

B B de Vries  1 , D J Halley, B A Oostra, M F Niermeijer
Affiliations
Review

The fragile X syndrome

B B de Vries et al. J Med Genet. 1998 Jul.

Abstract

The fragile X syndrome is characterised by mental retardation, behavioural features, and physical features, such as a long face with large protruding ears and macro-orchidism. In 1991, after identification of the fragile X mental retardation (FMR1) gene, the cytogenetic marker (a fragile site at Xq27.3) became replaced by molecular diagnosis. The fragile X syndrome was one of the first examples of a "novel" class of disorders caused by a trinucleotide repeat expansion. In the normal population, the CGG repeat varies from six to 54 units. Affected subjects have expanded CGG repeats (>200) in the first exon of the FMR1 gene (the full mutation). Phenotypically normal carriers of the fragile X syndrome have a repeat in the 43 to 200 range (the premutation). The cloning of the FMR1 gene led to the characterisation of its protein product FMRP, encouraged further clinical studies, and opened up the possibility of more accurate family studies and fragile X screening programmes.

PubMed Disclaimer

Comment in

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Nat Genet. 1996 Jan;12(1):91-3 - PubMed
    1. Biochem Biophys Res Commun. 1996 Aug 5;225(1):27-33 - PubMed
    1. J Med Genet. 1993 Jun;30(6):454-9 - PubMed
    1. Lancet. 1992 May 16;339(8803):1210-3 - PubMed
    1. Nat Genet. 1993 Jun;4(2):147-53 - PubMed

Publication types

Substances