DNA Testing and Genetic Genealogy

DNAhelixGenetic genealogy is based on the results you receive from DNA testing. The amount of DNA you share with another person determines your genetic relationship (Example: immediate family, 1st cousin, distant cousin). Your genetic cousins may not match your genealogical cousins, since everyone inherits a different combination of DNA from previous generations.


There are four types of DNA tests:

  • Autosomal DNA: Combined inherited DNA from both your paternal and maternal ancestors. Results usually extend back 5 to 6 generations (with each new generation, less DNA is inherited from distant generations). Anyone can take an Autosomal DNA test.
  • Y-Chromosome DNA: DNA inherited only through the male line (passed from grandfather to father to son). Only men can take a Y-Chromosome DNA test.
  • Mitochondrial DNA: DNA inherited through the female line by all of her children (both female and male) but only passed down through daughters (passed from grandmother to mother to daughters). Both women and men can take a Mitochondrial DNA test.
  • Combination DNA Test: Combines Autosomal with Y-Chromosome and/or Mitochondrial DNA testing (women cannot be tested for Y-Chromosome DNA). Both women and men can take a Combination DNA test.

There are many reasons to participate in DNA testing. Most people are curious about their ethnicity and are interested in matching with genetic cousins (cousins that share some of your DNA). Other motivations include questions about paternity, learning your haplogroup (deep ancestry) or finding out about your genetic medical background.

There are four major DNA testing companies:

Each testing company offers specific results, services, tools and analysis. To proceed, first determine the reason you want to take a DNA test, then match your reason with the appropriate DNA test and testing company. We recommend thoroughly evaluating each company and the type of test they offer before making your decision.


Helpful Research Links:

International Society of Genetic Genealogy – Autosomal DNA testing comparison chart

DNAeXplained – Genetic Genealogy: Demystifying Autosomal DNA Matching

International Society of Genetic Genealogy Wiki: Y chromosome DNA tests

International Society of Genetic Genealogy Wiki: Mitochondrial DNA tests


Order a DNA Test:

DNA testing kits are available through this website. We offer a variety of tests through three different companies: Ancestry.com, FamilyTree DNA and 23andMe. For information and to order please go to the Genetti Family Online Shop – click here.


Books About DNA Testing and Genetic Genealogy:

Guide to DNA Testing: How to Identify Ancestors, Confirm Relationships, and Measure Ethnic Ancestry through DNA Testing

Finding Family: My Search for Roots and the Secrets in My DNA

Genetic Genealogy: The Basics and Beyond

Genealogy: DNA and the Family Tree, 2nd Edition

The Family Tree Guide to DNA Testing and Genetic Genealogy


Disclaimer: All products for sale on this page are provided and shipped by third party companies. I am an affiliate for these companies and use affiliate links from FamilyTree DNA and Amazon. My compensation is a small percentage of the sales made through these links which support the expense of maintaining this website and my genealogy research. Donations towards the upkeep of this website are also humbly accepted.

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