What is "Fragile E Syndrome" ?

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Request for Question Clarification by skermit-ga on 27 May 2003 07:59 PDT

Are you sure it's not Fragile X Syndrome? I have found lots of
information about this, but not Fragile E.

skermit-ga

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Request for Question Clarification by skermit-ga on 27 May 2003 08:01 PDT

Here's is one source:

http://www.fraxa.org/html/about_cause.htm

skermit-ga

Hello -

As magnesium points out below, "Fragile E syndrome" is synonymous with
FRAXE syndrome - this is related to Fragile X syndrome, but occurs at
a different spot on the chromosome from the typical Fragile X syndrome
(also known as FRAXA).

Fragile X syndrome (and Fragile XE by extension) are congenital birth
defects caused by mutations in the X chromosome.  Fragile X syndrome
is result of mutations near the FMR1 (Fragile X mental retardation
gene 1) gene.
http://www.discoveryifi.org/Resources/Packetupload/Fragile_X_website_version_2003.pdf

Fragile X is caused by a tri-nucleotide repeat mutation (CGG) which
differs from the GCC repeat mutation in Fragile E syndrom (see below):
http://www.stanford.edu/group/hopes/rltdsci/trinuc/f9.html

The defect in Fragile XE is the result of abnormal expansions in the
chromosome (abnormal genetic material inserted where it shouldn't be)
X (chromosome X is one of the "sex" chromosomes, males have one copy
of chromosome X and one copy of chromosome Y - females have two copies
of the X chromosome - males more commonly have fragile X due to the
fact that it only takes one bad copy of the X chromosome for symptoms
to surface, whereas a female has two copies, only one of which is
active, therfore she only has a 50% chance) near the FMR2 gene
(Fragile X mental retardation gene 2).
http://journals.cup.cam.ac.uk/bin/bladerunner?30REQEVENT=&REQAUTH=0&500000REQSUB=&REQSTR1=S0003480000007983

Fragile XE syndrome is a case of tri-nucleotide repeat disease (in
which a triplet of nucleotides is inserted into the DNA multiple times
- ie. where one set of 'GCC' should be, instead 'GCCGCCGCCGCCGCC....'
is found - this is potentially due to the manner in which DNA is
replicated - it is easy for the DNA polymerase, the enzyme which makes
new DNA, to get "lost" and repeat similar sequences): (abstract only -
full article requires subscription)
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11246464&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10222796&dopt=Abstract

FRAXE usually has less severe mental retardation than is seen with
Fragile X, albeit with less severe physical appearance (see section on
FRAXE):
http://www.geneclinics.com/profiles/fragilex/details.html

A reasonable description of Fragile X from eMedicine.com:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10222796&dopt=Abstract

Another reasonable description of the disease:
http://www.geneclinics.org/profiles/fragilex/details.html



Please let me know if you have further questions.

synarchy

Search strategy:
"fragile xe"
"fragile x" xe

Fragile E Syndrome is another name for Fragile XE Syndrome (FRAXE Syndrome).

http://www.synergene.net/genelist.asp

http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?309548