So what are you waiting for? If your family’s genetic signature hasn’t yet been tested, how about considering contributing to the genealogical record and resource for your family by finding one or two men to take a Y-DNA test. If you are a male S-NN-T descendant then please check out the Sinnott/Sennett (and variants) surname project at familytreeDNA.com – you even get a discounted rate for the Y-DNA37 test if ordered through the project. http://www.familytreedna.com/group-join.aspx?Group=Sennett
Health and disease info: DNA testing can also indicate which conditions for which you may have a preponderance. It's a controversial feature, to be sure. Knowing that you have a genetic predisposition to a certain form of cancer may make you more vigilant for testing, but it may also lead to increased stress -- worrying about a potential condition that may never develop, even if you're "genetically susceptible" to it. The possibility of false positives and false negatives abound -- any such information should be discussed with your doctor before you act upon it.
Getting the most out of your AncestryDNA results requires a bit of work, as the DNA test works best in concert with the site’s other available resources. You can use the DNA service without creating a family tree, though the results are much less interesting. Ancestry uses information gleaned from its user’s DNA and family trees to create compelling stories about your family’s recent history and migrations. Testers with European roots could trace their family’s movements across the Atlantic and see what stops they made on their way across the U.S.
If you are interested in doing in-depth analysis, the firm offers a chromosome browser, allows raw data to be uploaded, provides support for setting different segment matching thresholds, and allows up to five comparisons to be done at once. Family Tree DNA allows trial transfers from 23andMe and AncestryDNA into its match database; additional transfers of various datasets is available for a fee. The company promises to keep data for 25 years.
1. Family Tree DNA’s Family Finder: One of the first to offer these types of tests, FTDNA is generally considered the leader in autosomal DNA testing for ancestry and provides some of the best tools available for genealogists. Their population finder section is currently a bit less specific than the other companies, but FTDNA Family Finder users are eagerly awaiting a much improved update to be released sometime in the next month. Find out about Family Finder here.