Length of uninterrupted CGG repeats determines instability in the FMR1 gene
- 1 September 1994
- journal article
- Published by Springer Nature in Nature Genetics
- Vol. 8 (1) , 88-94
- https://doi.org/10.1038/ng0994-88
Abstract
Analysis of 84 human X chromosomes for the presence of interrupting AGG trinucleotides within the CGG repeat tract of the FMR1 gene revealed that most alleles possess two interspersed AGGs and that the longest tract of uninterrupted CGG repeats is usually found at the 3' end. Variation in the length of the repeat appears polar. Alleles containing between 34 and 55 repeats, with documented unstable transmissions, were shown to have lost one or both AGG interruptions. These comparisons define an instability threshold of 34-38 uninterrupted CGG repeats. Analysis of premutation alleles in Fragile X syndrome carriers reveals that 70% of these alleles contain a single AGG interruption. These data suggest that the loss of an AGG is an important mutational event in the generation of unstable alleles predisposed to the Fragile X syndrome.Keywords
This publication has 35 references indexed in Scilit:
- Robust amplification and ethidium‐visible detection of the fragile X syndrome CGG repeat using Pfu polymeraseAmerican Journal of Medical Genetics, 1994
- Allelic diversity at minisatellite MS205 (D16S309): evidence for polarized variabilityHuman Molecular Genetics, 1993
- Origins of the fragile X syndrome mutation.Journal of Medical Genetics, 1993
- A Tetranucleotide Repeat Mouse Minisatellite Displaying Substantial Somatic Instability during Early Preimplantation DevelopmentGenomics, 1993
- Human and murine FMR-1: alternative splicing and translational initiation downstream of the CGG–repeatNature Genetics, 1993
- Fragile X syndrome: genetic localisation by linkage mapping of two microsatellite repeats FRAXAC1 and FRAXAC2 which immediately flank the fragile site.Journal of Medical Genetics, 1991
- Variation of the CGG repeat at the fragile X site results in genetic instability: Resolution of the Sherman paradoxCell, 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