Prevalence Tables

The following table is based on regularly updated data representing the observations of deleterious mutations in the MLH1 and MSH2 genes by Myriad Genetic Laboratories, Inc. through our clinical testing service. Prevalence data for MSH6 mutations, which account for 10% to 15% of detectable mutations in HNPCC, are not yet available. These data were obtained from a routine laboratory requisition form and have not been independently verified. Data obtained through testing performed under specific research protocols and data for whom relevant information was not provided are excluded from this tabulation. Personal History categories will be added as data becomes available.


Personal History No Affected Relatives ‰¥ 1 Relative Affected
Colorectal Cancer < 50 7.2% 27.5%
Colorectal Cancer ‰¥ 50 4.4% 14.1%
Endometrial Cancer < 50 7.0%* 29.9%
Other Lynch Syndrome Cancer 3.6%** 14.3%
>1 Lynch Syndrome Cancer 8.8% 45.8%

*Estimate calculated according to PREMM12 model; Myriad’s N < 25

**Myriad’s N < 50