DNA Basics

What is DNA?

Deoxyribonucleic acid (DNA) is a molecule found in nearly all human cells and contains the information for the development and function of all living organisms. A human DNA molecule is a double helix shaped like a twisted ladder. The human genome is the complete set of human genetic information found within 23 pairs of chromosomes for each person. Half of the chromosomes come from the father and half from the mother. These 23 chromosomes reside within the nucleus of the cells and some DNA is also found in the mitochondria.

Learn more about DNA and how it is inherited

Why use it in family history research?

Some of the reasons you may want to use DNA in your family history research:

• Break down a brick wall where paper records may not exist to solve the problem
• Confirm the relationship between two people or families
• Learn about deep ancestry and ethnicity
• Locate the biological parents of adoptees or people who don't know their parentage
• Verify ancestral lines found through paper records

DNA testing risks

May disclose information you weren’t expecting such as:

• Adoptions
• Illegitimacies
• Non-paternal events (NPEs where parentage may be unexpected)
• Name changes

Types of DNA tests

• atDNA (autosomal) males and females
• mtDNA (mitochondrial DNA passed from a mother to each of her children) males and females
• Y-DNA (DNA passed from father to son) males only

DNA testing companies

• 23 and Me
  • Autosomal (with paternal and maternal Haplogroups)
• AncestryDNA
  • Autosomal
• FamilyTree DNA
  • Autosomal Family Finder
  • mt-DNA (with maternal Haplogroup)
  • Y-DNA (37 markers through 111 markers with paternal Haplogroup)
• MyHeritage
  • Autosomal

Online Classes

• FamilyTree DNA courses https://www.familytreedna.com/learn/ftdna/webinars/
• GeneTech at FamilySearch https://familysearch.org/ask/learningViewer/276
• ISOGG Courses (International Society of Genetic Genealogy) https://isogg.org/wiki/Genetics_courses

Additional information

• Hiring a DNA Testing Company Familysearch Wiki page

• Wiki of the International Society of Genetic Genealogy (ISOGG)

Facebook Groups

• 23andMe Newbies- This is a closed group for those who are beginning genetic testing with 23andMe and discussing genealogy and health.
• Autosomal DNA- This group talks about geographical and historical origins of your genetic markers.
• DNA Detectives- From their Facebook group "The DNA Detectives group is focused on bringing together volunteers with genetic genealogy and searching experience with those seeking biological family -- adoptees, foundlings, donor-conceived individuals, unknown paternity and all other types of unknown parentage cases, near or far. This group is for members helping members and self-education."
• International Society of Genetic Genealogy (ISOGG)- From their Facebook group The mission of the International Society of Genetic Genealogy is to advocate for and educate about the use of genetics as a tool for genealogical research, and promote a supportive network for genetic genealogists."