Physical mapping across the fragile X: Hypermethylation and clinical expression of the fragile X syndrome

doi:10.1016/0092-8674(91)90514-Y

Cell

Volume 64, Issue 4, 22 February 1991, Pages 861-866

https://doi.org/10.1016/0092-8674(91)90514-Y Get rights and content

Abstract

The most common genetic cause of mental retardation after Down's syndrome, the fragile X syndrome, is associated with the occurrence of a fragile site at Xq27.3. This X-linked disease is intriguing because transmission can occur through phenotypically normal males. Theories to explain this unusual phenomenon include genomic rearrangements and methylation changes associated with a local block of reactivation of the X chromosome. Using microdisected markers close to the fragile site, we have been able to test these hypotheses. We present evidence for the association of methylation with the expression of the disease. However, there is no simple relationship between the degree of methylation and either the level of expression of the fragile site or the severity of the clinical phenotype.

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Cell

ArticlePhysical mapping across the fragile X: Hypermethylation and clinical expression of the fragile X syndrome

Abstract

Anal. Biochem.

Cell

Trends Genet.

Genomics

J. Biol. Chem.

J. Pediatr.

Partial Notl digests, generated by low enzyme concentration of the presence of ethidium bromide, can be used to extend the range of pulsed field gel mapping

Technique

Linkage analysis of families with fragile-X mental retardation using a novel RFLP marker (DXS304)

Am. J. Hum. Genet.

Linkage studies of X-linked mental retardation: high frequency of recombination in the telomeric region of the human X chromosome

Hum. Genet.

X-linked mental retardation and the fragile X syndrome: a clinical approach

Prevalence of the fragile-X syndrome in mentally retarded children in a Swedish county

Am. J. Med. Genet.

The fragile X: a scanning electron microscope study

J. Med. Genet.

Linear order of new and established DNA markers around the fragile site at Xq27.3

Genomics

Active X chromosome DNA is unmethylated at eight CCGG sites clustered in a guanosine-plus-cytosine-rich island at the 5′ end of the gene for phosphoglycerate kinase

Mol. Cell. Biol.

Use of restriction enzymes to detect potential gene sequences in mammalian DNA

Nature

A marker X-chromosome

Am. J. Hum. Genet.

Microdissection of the fragile X region

Am. J. Hum. Genet.

Article
Physical mapping across the fragile X: Hypermethylation and clinical expression of the fragile X syndrome