Comment by apaprocki

In the US, President Bush signed the Genetic Information Nondiscrimination Act of 2008 which covers these topics. Some relevant parts are available here: http://thomas.loc.gov/cgi-bin/bdquery/z?d110:HR00493:

edit: Specifically, "`(A) IN GENERAL- For purposes of this section, a group health plan, and a health insurance issuer offering group health insurance coverage in connection with a group health plan, may not adjust premium or contribution amounts for the group covered under such plan on the basis of genetic information."