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.
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?
Most examples of hereditary non-polyposis cancer syndrome (Lynch syndrome), including the Muir-Torre syndrome, are associated with microsatellite instability (MSI) and germline mutations in mismatch repair genes-most commonly MLH1 or MSH2.
Muir-Torre syndrome is usually inherited in an autosomal dominant fashion and associated with mutations in the mismatch repair genes, predominantly in MLH1 and MSH2 genes.
Four (44%) of nine families with MLH1 mutations had a member with Muir-Torre syndrome compared with 10 (42%) of 24 families with MSH2 mutations (P = .302).
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.
Value of MLH1 and MSH2 mutations in the appearance of Muir-Torre syndrome phenotype in HNPCC patients presenting sebaceous gland tumors or keratoacanthomas.