The full mutation in the FMR–1 gene of male fragile X patients is absent in their sperm

@article{Reyniers1993TheFM,
  title={The full mutation in the FMR–1 gene of male fragile X patients is absent in their sperm},
  author={Edwin Reyniers and Lieve Vits and Kristel De Boulle and Bernadette Van Roy and D{\'e}sir{\'e}e Van Velzen and Esther de Graaff and Annemieke J M H Verkerk and H Z Jorens and John K. Darby and Ben A. Oostra and Patrick J. Willems},
  journal={Nature Genetics},
  year={1993},
  volume={4},
  pages={143-146}
}
Fragile X syndrome is characterized at the molecular level by amplification of a (CGG)n repeat and hypermethylation of a CpG island preceeding the open reading frame of the fragile X gene (FMR–1) located in Xq27.3. Anticipation in this syndrome is associated with progressive amplification of the (CGG)n repeat from a premutation to a full mutation through consecutive generations. Remarkably, expansion of the premutation to the full mutation is strictly maternal. To clarify this parental… 

Instability of the CGG repeat and expression of the FMR1 protein in a male fragile X patient with a lung tumor.

TLDR
The results found in the tumor suggest that the CpGs in these restriction sites are not essential for regulation of FMR1 expression, and there is a need for a more accurate study of the exact promoter of F MRP.

Unexpected Inheritance of the (CGG)n Trinucleotide Expansion in a Fragile X Syndrome Family

TLDR
Findings from this family study corroborate the hypothesis that the expansion during female transmission could be a postzygotic event and raise the problem of mosaicism.

The fragile X mutation

TLDR
Possible mechanisms of expansion in light of the unusual structural properties proposed for CGG repeats are discussed and various other folate-sensitive fragile sites that are also caused by unstable expansions of CGG (CCG) repeats are being cloned and characterized.

Transition from premutation to full mutation in fragile X syndrome is likely to be prezygotic.

TLDR
Analysis of tissues from affected fetuses indicate that such a putative postzygotic transition would have to occur very early in embryogenesis and most likely before determination of germ cell lineage, and it is proposed that this is strong, albeit indirect evidence against a postzyGotic transition to FM.

Postmortem examination of two fragile X brothers with an FMR1 full mutation.

TLDR
No evidence for extensive mitotic expansion of the CGG repeat during fetal or postnatal life of a fragile X patient was found, in contrast to dynamic mutations caused by CAG/CTG repeat expansion.

Fragile X syndrome and the (CGG)n mutation: two families with discordant MZ twins.

TLDR
Two families in which discordance between two sets of MZ twins illustrates two important genetic points are presented, demonstrating in vivo mitotic instability of this CGG repeat and suggesting that the transition to the full mutation occurred postzygotically.

Characterization of the full fragile X syndrome mutation in fetal gametes

TLDR
Analysis of intact ovaries of full mutation fetuses shows that only full expansion alleles can be detected in oocytes (but in the unmethylated state), discounting the hypothesis that the germline is protected from full expansion and suggest full mutation contraction in the immature testis.

Reversion to Normal of FMR1 Expanded Alleles: A Rare Event in Two Independent Fragile X Syndrome Families

TLDR
Two unaffected boys in two independent FXS families who inherited a non-mosaic allele in the normal and intermediate range, respectively, from their mothers who are carriers of an expanded CGG allele are described.

Paternal transmission of fragile X syndrome

TLDR
A family in which a fragile X mosaic male has a daughter with both premutation and partially methylated full mutation alleles and a significant developmental disability is presented, the first report of such an occurrence and it challenges current thinking about the expansion and transmission of unstable FMR1 alleles from men to their daughters.
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TLDR
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TLDR
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TLDR
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TLDR
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TLDR
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TLDR
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TLDR
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