Collins SC, Coffee B, Benke PJ, Berry-Kravis E, Gilbert F, Oostra B, Halley D, Zwick ME, Cutler DJ, Warren ST. Array-based FMR1 sequencing and deletion analysis in patients with a fragile X syndrome-like phenotype.
PLoS One 2010;
5:e9476. [PMID:
20221430 PMCID:
PMC2832695 DOI:
10.1371/journal.pone.0009476]
[Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 02/11/2010] [Indexed: 11/18/2022] Open
Abstract
Background
Fragile X syndrome (FXS) is caused by loss of function mutations in the FMR1 gene. Trinucleotide CGG-repeat expansions, resulting in FMR1 gene silencing, are the most common mutations observed at this locus. Even though the repeat expansion mutation is a functional null mutation, few conventional mutations have been identified at this locus, largely due to the clinical laboratory focus on the repeat tract.
Methodology/Principal Findings
To more thoroughly evaluate the frequency of conventional mutations in FXS-like patients, we used an array-based method to sequence FMR1 in 51 unrelated males exhibiting several features characteristic of FXS but with normal CGG-repeat tracts of FMR1. One patient was identified with a deletion in FMR1, but none of the patients were found to have other conventional mutations.
Conclusions/Significance
These data suggest that missense mutations in FMR1 are not a common cause of the FXS phenotype in patients who have normal-length CGG-repeat tracts. However, screening for small deletions of FMR1 may be of clinically utility.
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