Assessing pathogenicity of MLH1 variants by co-expression of human MLH1 and PMS2 genes in yeast.

摘要: Loss of DNA mismatch repair (MMR) in humans, mainly due to mutations the hMLH1 gene, is linked hereditary nonpolyposis colorectal cancer (HNPCC). Because not all MLH1 alterations result loss MMR function, accurate characterization variants and their classification terms effect on function essential for reliable genetic testing effective treatment. To date, vivo assays functional performed various model systems have used episomal expression modified genes. We describe here a novel approach determine accurately significance vivo, based co-expression human PMS2 yeast cells. Yeast PMS1 genes, whose protein products form MutLα complex, were replaced by orthologs directly chromosomes homologous recombination, resulting activity was tested. The strain co-expressing hPMS2 exhibited same mutation rate as wild-type. Eight cancer-related introduced, using approach, into prepared model, determined. Five (A92P, S93G, I219V, K618R K618T) classified non-pathogenic, whereas T117M, Y646C R659Q characterized pathogenic. Results our yeast-based correlate well with clinical data five out seven described thus shown be useful patients found throughout entire coding region gene.