High-resolution melting (HRM) re-analysis of a polyposis patients cohort reveals previously undetected heterozygous and mosaic APC gene mutations

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Model polydiethylsiloxane networks I. Synthesis and phase behaviour

The preparation and hydrosilylation crosslinking of well-defined vinyl and ally polydiethylsiloxane (PDES) telechelics are described. End functionalization has been achieved by using divinyltetramethylsiloxane as a chain stopper during the cationic polymerization of hexaethylcyclotrisiloxane or by anionic polymerization of hexaethylcyclotrisiloxane with allyllithium followed by end capping with allyldimethylchlorosilane. Hydrosilylation crosslinking yielded model PDES networks which have been characterized by equilibrium swelling, determination of the sol fraction, differential scanning calorimetry and wide angle X-ray diffraction

Increased MUTYH mutation frequency among Dutch families with breast cancer and colorectal cancer

Homozygous and compound heterozygous MUTYH mutations predispose for MUTYH-associated polyposis (MAP). The clinical phenotype of MAP is characterised by the multiple colorectal adenomas and colorectal carcinoma. We previously found that female MAP patients may also have an increased risk for breast cancer. Yet, the involvement of MUTYH mutations in families with both breast cancer and colorectal cancer is unclear. Here, we have genotyped the MUTYH p.Tyr179Cys, p.Gly396Asp and p.Pro405Leu founder mutations in 153 Dutch families with breast cancer patients and colorectal cancer patients. Families were classified as polyposis, revised Amsterdam criteria positive (FCRC-AMS positive), revised Amsterdam criteria negative (FCRC-AMS negative), hereditary breast and colorectal cancer (HBCC) and non-HBCC breast cancer families. As anticipated, biallelic MUTYH mutations were identified among 13% of 15 polyposis families, which was significantly increased compared to the absence of biallelic MUTYH mutations in the population (P = 0.0001). Importantly, six heterozygous MUTYH mutations were identified among non-polyposis families with breast and colorectal cancer. These mutations were identified specifically in FCRC-AMS negative and in HBCC breast cancer families (11% of 28 families and 4% of 74 families, respectively; P = 0.02 for both groups combined vs. controls). Importantly, the 11% MUTYH frequency among FCRC-AMS negative families was almost fivefold higher than the reported frequencies for FCRC-AMS negative families unselected for the presence of breast cancer patients (P = 0.03). Together, our results indicate that heterozygous MUTYH mutations are associated with families that include both breast cancer patients and colorectal cancer patients, independent of which tumour type is more prevalent in the family.Molecular tumour pathology - and tumour genetic

MUTYH gene variants and breast cancer in a Dutch case-control study

The MUTYH gene is involved in base excision repair. MUTYH mutations predispose to recessively inherited colorectal polyposis and cancer. Here, we evaluate an association with breast cancer (BC), following up our previous finding of an elevated BC frequency among Dutch bi-allelic MUTYH mutation carriers. A case–control study was performed comparing 1,469 incident BC patients (ORIGO cohort), 471 individuals displaying features suggesting a genetic predisposition for BC, but without a detectable BRCA1 or BRCA2 mutation (BRCAx cohort), and 1,666 controls. First, for 303 consecutive patients diagnosed before age 55 years and/or with multiple primary breast tumors, the MUTYH coding region and flanking introns were sequenced. The remaining subjects were genotyped for five coding variants, p.Tyr179Cys, p.Arg309Cys, p.Gly396Asp, p.Pro405Leu, and p.Ser515Phe, and four tagging SNPs, c.37-2487G>T, p.Val22Met, c.504+35G>A, and p.Gln338His. No bi-allelic pathogenic MUTYH mutations were identified. The pathogenic variant p.Gly396Asp and the variant of uncertain significance p.Arg309Cys occurred twice as frequently in BRCAx subjects as compared to incident BC patients and controls (p=0.13 and p=0.15, respectively). The likely benign variant p.Val22Met occurred less frequently in patients from the incident BC (p=0.03) and BRCAx groups (p=0.11), respectively, as compared to the controls. Minor allele genotypes of several MUTYH variants showed trends towards association with lobular BC histology. This extensive case–control study could not confirm previously reported associations of MUTYH variants with BC, although it was too small to exclude subtle effects on BC susceptibility

The extended OPAL silicon strip microvertex detector

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