These methods have been used to analyze two large HNPCC kindreds exhibiting features of the Muir-Torre syndrome and demonstrate that cancer susceptibility is due to the inheritance of a frameshift mutation in the MSH2 gene in one family and a nonsense mutation in the MSH2 gene in the other family.
We did not detect any correlation between clinical phenotype and the genetic linkage results, but a Muir-Torre syndrome family excluded from linkage to hMLH1 was likely to be linked to hMSH2 and showed microsatellite instability in a tumour from an affected relative.
We did not detect any correlation between clinical phenotype and the genetic linkage results, but a Muir-Torre syndrome family excluded from linkage to hMLH1 was likely to be linked to hMSH2 and showed microsatellite instability in a tumour from an affected relative.
Sixteen rare sequence variants of the hMLH1 and hMSH2 genes found in a cohort of 254 suspected HNPCC (hereditary non-polyposis colorectal cancer) patients: mutations or polymorphisms?
Thus, we could show in a sample of sebaceous tumors from patients with genetically proven Muir-Torre syndrome that loss of heterozygosity most probably is not the preferred mode of somatic inactivation of the second MSH2 allele.
The presence of microsatellite instability in transplant-associated lesions, together with loss of hMSH2 expression suggests that immunosuppression might unmask a previously silent Muir-Torre syndrome phenotype in some cases.
Loss of DNA mismatch repair proteins in skin tumors from patients with Muir-Torre syndrome and MSH2 or MLH1 germline mutations: establishment of immunohistochemical analysis as a screening test.
Biopsy specimens of periocular sebaceous gland carcinoma obtained from six patients (mean age, 60 +/- 17 years; range, 38 to 83 years, 5 male, 1 female) with Muir-Torre syndrome and histopathologically proven sebaceous gland carcinoma were studied immunohistochemically for the presence of fragile histidine triad protein.