The full mutation in the FMR–1 gene of male fragile X patients is absent in their sperm
- 1 June 1993
- journal article
- research article
- Published by Springer Nature in Nature Genetics
- Vol. 4 (2) , 143-146
- https://doi.org/10.1038/ng0693-143
Abstract
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 influence we studied FMR–1 in sperm of four male fragile X patients. This showed that only the premutation was present in their sperm, although they had a full mutation in peripheral lymphocytes. This might suggest that expansion of the premutation to the full mutation in FMR–1 does not occur in meiosis but in a postzygotic stage.Keywords
This publication has 44 references indexed in Scilit:
- A point mutation in the FMR-1 gene associated with fragile X mental retardationNature Genetics, 1993
- Unstable DNA may be responsible for the incomplete penetrance of the myotonic dystrophy phenotypeHuman Molecular Genetics, 1992
- Segregation of the fragile X mutation from an affected male to his normal daughterHuman Molecular Genetics, 1992
- Heritable unstable DNA sequencesNature Genetics, 1992
- Variation of the CGG repeat at the fragile X site results in genetic instability: Resolution of the Sherman paradoxCell, 1991
- The use of synthetic tandem repeats to isolate new VNTR loci: Cloning of a human hypermutable sequenceGenomics, 1991
- Absence of expression of the FMR-1 gene in fragile X syndromeCell, 1991
- Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndromePublished by Elsevier ,1991
- Further segregation analysis of the fragile X syndrome with special reference to transmitting malesHuman Genetics, 1985
- The marker (X) syndrome: a cytogenetic and genetic analysisAnnals of Human Genetics, 1984