z-logo
Premium
Quantitative sequence analysis of FBN1 premature termination codons provides evidence for incomplete NMD in leukocytes
Author(s) -
Magyar István,
Colman Dvora,
Arnold Eliane,
Baumgartner Daniela,
Bottani Armand,
Fokstuen Siv,
Addor MarieClaude,
Berger Wolfgang,
Carrel Thierry,
Steinmann Beat,
Mátyás Gábor
Publication year - 2009
Publication title -
human mutation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 162
eISSN - 1098-1004
pISSN - 1059-7794
DOI - 10.1002/humu.21058
Subject(s) - biology , sanger sequencing , genomic dna , microbiology and biotechnology , nonsense mediated decay , genetics , missense mutation , gene , allele , single nucleotide polymorphism , mutation , genotype , rna , rna splicing
Abstract We improved, evaluated, and used Sanger sequencing for quantification of single nucleotide polymorphism (SNP) variants in transcripts and gDNA samples. This improved assay resulted in highly reproducible relative allele frequencies (e.g., for a heterozygous gDNA 50.0±1.4%, and for a missense mutation‐bearing transcript 46.9±3.7%) with a lower detection limit of 3–9%. It provided excellent accuracy and linear correlation between expected and observed relative allele frequencies. This sequencing assay, which can also be used for the quantification of copy number variations (CNVs), methylations, mosaicisms, and DNA pools, enabled us to analyze transcripts of the FBN1 gene in fibroblasts and blood samples of patients with suspected Marfan syndrome not only qualitatively but also quantitatively. We report a total of 18 novel and 19 known FBN1 sequence variants leading to a premature termination codon (PTC), 26 of which we analyzed by quantitative sequencing both at gDNA and cDNA levels. The relative amounts of PTC‐containing FBN1 transcripts in fresh and PAXgene‐stabilized blood samples were significantly higher (33.0±3.9% to 80.0±7.2%) than those detected in affected fibroblasts with inhibition of nonsense‐mediated mRNA decay (NMD) (11.0±2.1% to 25.0±1.8%), whereas in fibroblasts without NMD inhibition no mutant alleles could be detected. These results provide evidence for incomplete NMD in leukocytes and have particular importance for RNA‐based analyses not only in FBN1 but also in other genes. Hum Mutat 30:1–10, 2009. © 2009 Wiley‐Liss, Inc.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here