Germline MSH2 and MLH1 mutational spectrum including large rearrangements in HNPCC families from Poland (update study)

Jagiellonian University, Cracovia, Lesser Poland Voivodeship, Poland
Clinical Genetics (Impact Factor: 3.93). 02/2006; 69(1):40-7. DOI: 10.1111/j.1399-0004.2006.00550.x
Source: PubMed


Germline mutations in the DNA mismatch repair genes MSH2 and MLH1 account for a significant proportion of hereditary non-polyposis colorectal cancer (HNPCC) families. One approach by which development of an efficient DNA-testing procedure can be implemented is to describe the nature and frequency of common mutations in particular ethnic groups. Two hundred and twenty-six patients from families matching the Amsterdam II diagnostic criteria or suspected HNPCC criteria were screened for MSH2 and MLH1 germline mutations. Fifty different pathogenic mutations were found, 25 in MSH2 and 25 in MLH1. Twenty-four of these had not previously been described in other populations. Among our 78 families with MSH2 or MLH1 mutations, 54 (69.2%) were affected by recurrent mutations including 38 found at least twice in our own series. Two of the most frequent alterations were a substitution of A to T at the splice donor site of intron 5 of MSH2 and a missense change (A681T) of MLH1 found in 10 and eight families, respectively. Among large deletions detected by the multiplex ligation-dependent probe amplification assay, exon 9 deletions in the MSH2 gene were found in two families. Our results indicate that a screening protocol specific for the Polish population that is limited to the detection of all reported mutations will result in the identification of the majority of changes present in MLH1 and MSH2 genes in Polish HNPCC kindreds.

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Available from: Dariusz Godlewski, Sep 29, 2015
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    • "At amino acid position 120, Rabbit has a polar uncharged Serine residue while all other species tested have a hydrophobic Alanine residue. This positively selected site falls in a region dense with HNPCC2 variants at positions A111V, T116K, T117M, Y126N, A128P [63-65]. Positively selected residues in Rabbit: 209, 478 and 514, each fall within 8 amino acid positions of HNPCC2 variants: V213M, R474Q and V506A [66]. "
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    ABSTRACT: Background Cancer, much like most human disease, is routinely studied by utilizing model organisms. Of these model organisms, mice are often dominant. However, our assumptions of functional equivalence fail to consider the opportunity for divergence conferred by ~180 Million Years (MY) of independent evolution between these species. For a given set of human disease related genes, it is therefore important to determine if functional equivalency has been retained between species. In this study we test the hypothesis that cancer associated genes have different patterns of substitution akin to adaptive evolution in different mammal lineages. Results Our analysis of the current literature and colon cancer databases identified 22 genes exhibiting colon cancer associated germline mutations. We identified orthologs for these 22 genes across a set of high coverage (>6X) vertebrate genomes. Analysis of these orthologous datasets revealed significant levels of positive selection. Evidence of lineage-specific positive selection was identified in 14 genes in both ancestral and extant lineages. Lineage-specific positive selection was detected in the ancestral Euarchontoglires and Hominidae lineages for STK11, in the ancestral primate lineage for CDH1, in the ancestral Murinae lineage for both SDHC and MSH6 genes and the ancestral Muridae lineage for TSC1. Conclusion Identifying positive selection in the Primate, Hominidae, Muridae and Murinae lineages suggests an ancestral functional shift in these genes between the rodent and primate lineages. Analyses such as this, combining evolutionary theory and predictions - along with medically relevant data, can thus provide us with important clues for modeling human diseases.
    Full-text · Article · Jul 2012 · BMC Evolutionary Biology
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    • "Molecular studies enable the detection of mutation carriers and release from unreasonable stress of persons from the group with increased risk of cancer occurrence. The mutation spectrums in the genes predisposing to colorectal cancer in the Polish population have been described [1-4]. In the present work we focused on recurrent mutations of the APC gene causing FAP [5]. "
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    ABSTRACT: The molecular diagnostics of genetically conditioned disorders is based on the identification of the mutations in the predisposing genes. Hereditary cancer disorders of the gastrointestinal tracts are caused by mutations of the tumour suppressor genes or the DNA repair genes. Occurrence of recurrent mutation allows improvement of molecular diagnostics. The mutation spectrum in the genes causing hereditary forms of colorectal cancers in the Polish population was previously described. In the present work an estimation of the frequency of the recurrent mutations of the APC gene was performed. Eight types of mutations occurred in 19.4% of our FAP families and these constitute 43% of all Polish diagnosed families.
    Full-text · Article · Feb 2007 · Hereditary Cancer in Clinical Practice
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    • "Types and prevalence of MSH2 and MLH1 mutations in HNPCC families from Poland (Based on publication no. 3: Germline MSH2 and MLH1 mutational spectrum including large rearrangements in HNPCC families from Poland (update study) [30]*) "
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    ABSTRACT: This manuscript is composed of five parts which summarize five publications in succession. Essentially, they are concerned with molecular diagnostics of Lynch syndrome and are based on studies in 238 families. The finding that young age at diagnosis is the key feature in patients with MSH2 and MLH1 mutations (Part 1) has helped to define simple criteria for the preliminary diagnosis of this syndrome. A cheaper method for the detection of mutations has been developed (Part 2) and applied to study the types of mutations and their prevalence in Poland (Part 3) and the Baltic States (Part 4). A specific feature of these mutations, i.e. presence of recurrent mutations in the majority of affected families with mutations, has suggested the feasibility of effective diagnostics with a single test disclosing all of them. An attempt to reveal other causes of familial aggregation of colorectal cancer has ruled out any association with C insertion in the NOD2 gene (Part 5).
    Preview · Article · Dec 2006 · Hereditary Cancer in Clinical Practice
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