Document Detail


Recurrent and unexpected segregation of the FMR1 CGG repeat in a family with fragile X syndrome.
MedLine Citation:
PMID:  8834253     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Fragile X syndrome, the most common cause of hereditary mental retardation, results from amplification of a CGG trinucleotide repeat in the FMR1 gene. The transmission of the CGG repeat from premutated individuals to their premutated descendants is usually unstable, showing an increase in the size of the repeat. We report here a family which exhibits recurrent and unexpected transmission of the maternal premutation to three daughters. The first daughter exhibited mosaicism with two premutated alleles, one contracted and the other expanded. The second daughter showed a reversion from the maternal premutation to the normal range, and the third carried an expanded premutated allele associated with an expanded paternal allele within the normal range. These variations in the size of the CGG repeat may result from many different mechanisms such as DNA polymerase slippage on the leading or lagging strand during replication, large contractions of repeats on the parental strand during replication, or recombination through unequal crossover between sister chromatids. Our results suggest that the variation of the CGG premutated alleles in this family may be the result of intrinsic instability associated with a trans-acting factor such as a mismatch repair gene product.
Authors:
E Mornet; C Chateau; A Taillandier; B Simon-Bouy; J L Serre
Related Documents :
16276103 - Chromosomal assignment of lasp1 and lasp2 genes and organization of the lasp2 gene in c...
2574003 - Absence of a single repeat from the coding region of the human involucrin gene leading ...
3958563 - Long-term storage of eight-cell mouse embryos at - 196 degrees c.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Human genetics     Volume:  97     ISSN:  0340-6717     ISO Abbreviation:  Hum. Genet.     Publication Date:  1996 Apr 
Date Detail:
Created Date:  1996-12-03     Completed Date:  1996-12-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7613873     Medline TA:  Hum Genet     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  512-5     Citation Subset:  IM    
Affiliation:
Centre d'Etudes de Biologie Prénatale SESEP, Université de Versailles, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Female
Fragile X Mental Retardation Protein
Fragile X Syndrome / genetics*
Humans
Male
Nerve Tissue Proteins / genetics*
Pedigree
Polymerase Chain Reaction
RNA-Binding Proteins*
Repetitive Sequences, Nucleic Acid*
Chemical
Reg. No./Substance:
0/FMR1 protein, human; 0/Nerve Tissue Proteins; 0/RNA-Binding Proteins; 139135-51-6/Fragile X Mental Retardation Protein

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Abnormal gonadal differentiation in two subjects with ambiguous genitalia, Mullerian structures, and...
Next Document:  Proportion of the GSTM1 0/0 genotype in some Slavic populations and its correlation with cystic fibr...