Abstract |
Maturity-onset diabetes of the young ( MODY) 5 is caused by mutations in the TCF2 gene encoding the transcription factor hepatocyte nuclear factor-1beta. However, in 60% of the patients with a phenotype suggesting MODY5, no point mutation is detected in TCF2. We have hypothesized that large genomic rearrangements of TCF2 that are missed by conventional screening methods may account for this observation. In 40 unrelated patients presenting with MODY5 phenotype, TCF2 was screened for mutations by sequencing. Patients without mutations were then screened for TCF2 rearrangements by the quantitative multiplex PCR of short fluorescent fragments (QMPSF). Among the 40 patients, the overall detection rate was 70%: 18 had point mutations, 9 had whole-gene deletions, and 1 had a deletion of a single exon. Similar phenotypes were observed in patients with mutations and in subjects with large deletions. These results suggest that MODY5 is more prevalent than previously reported, with one-third of the cases resulting from large deletions of TCF2. Because QMPSF is more rapid and cost effective than sequencing, we propose that patients whose phenotype is consistent with MODY5 should be screened first with the QMPSF assay. In addition, other MODY genes should be screened for large genomic rearrangements.
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Authors | Christine Bellanné-Chantelot, Séverine Clauin, Dominique Chauveau, Philippe Collin, Michèle Daumont, Claire Douillard, Danièle Dubois-Laforgue, Laurent Dusselier, Jean-François Gautier, Michel Jadoul, Marie Laloi-Michelin, Laetitia Jacquesson, Etienne Larger, Jacques Louis, Marc Nicolino, Jean-François Subra, Jean-Marie Wilhem, Jacques Young, Gilberto Velho, José Timsit |
Journal | Diabetes
(Diabetes)
Vol. 54
Issue 11
Pg. 3126-32
(Nov 2005)
ISSN: 0012-1797 [Print] United States |
PMID | 16249435
(Publication Type: Journal Article)
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Chemical References |
- HNF1B protein, human
- Hepatocyte Nuclear Factor 1-beta
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Topics |
- Adolescent
- Adult
- Aged
- Alleles
- Base Sequence
- Chromosome Mapping
- Diabetes Mellitus, Type 2
(classification, genetics)
- Female
- Hepatocyte Nuclear Factor 1-beta
(genetics)
- Humans
- Male
- Middle Aged
- Molecular Sequence Data
- Mutation
(genetics)
- Phenotype
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