Current findings that some HNPCC patients carry aberrations exclusively in the TACSTD1 gene leading to the generation of TACSTD1/MSH2 fusion transcripts [46,47] led to the creation of a new version of the P003 kit (B1 version), including TASCTD1 probes to enable simultaneous MLPA analysis of this gene and the major MMR genes (MLH1 and MSH2). This evidence concerns the gene MRC1 and hereditary nonpolyposis colon cancer.