Were you born in the US after 1963? If so, your state of birth probably already screened you for genetic diseases at birth:

http://articles.latimes.com/2013/jul/19/opinion/la-oe-timmer...

Parental consent is not required – though with enough advance effort and written request, opting-out is possible.

Further, many states retain the "residual dried blood spots" for more than 6 months and perhaps indefinitely:

http://www.ncbi.nlm.nih.gov/pubmed/16737872

So a sample of your genetic material may already exist in a state government filing cabinet, somewhere. In California, the retained information and sample can be used "for medical intervention, counseling or specific research projects which the California Board of Health approves" and "anonymous research studies". See the section "Storage and Use of Dried Blood Spots" at:

http://www.babysfirsttest.org/newborn-screening/states/calif...

For newborns, the California program currently tests for 79 different disorders:

http://www.cdph.ca.gov/programs/nbs/Documents/NBS-DisordersD...

And the per-disease records are apparently kept for lookup-by-individual without retesting, because there's a routine by-email process for requesting long-ago sickle-cell results (back to 1990) about NCAA student athletes:

http://www.cdph.ca.gov/programs/nbs/Pages/NBSFAQTraitAthlete...

And that's not even considering all the health procedures (blood donations, tests, surgeries) or natural shedding (hairs, skin, saliva, excrement) routine in a normal life. You are a firehose of genetic samples, to any even slightly attentive observer, or even passive observers who take an interest some time later.

So: good luck keeping your genes from the state, if it really wants them.