Direct to consumer testing week 9 - Ancestry DNA testing Flashcards
why do a DNA test?
- Determine if two people are related
- Determine if two people descend from the same ancestor
- Find out if you are related to others with the same surname
- Prove or disprove your family tree research
- Go beyond brick wall in genealogy
- Provide clues about your ethnic origin
- To find out about genetic risk factors in health
Methods of ancestry DNA testing
- Y Chromosome
- Mitochondrial DNA
- Autosomal
- X chromosome
Short tandem Repeats (STRs)
the repeat region is variable between samples while the flanking regions where PCR primers bind are constant
Homozygote = both alleles are the same length
Heterozygote = alleles differ and can be resolved from one another
Branches and twigs - Haplogroups
• Haplogroups are the descents of mega-families that characterized early human migrations. They are normally associated with geographical regions. Examples: R1b (Western Atlantic European), I (northern Europe), J (Jewish, Middle Eastern).
Branches and twigs - Haplotype
• Haplotype - One person’s set of values for the markers that have been tested. Two individuals that match on all markers but one, have two distinct haplotypes. (One-step mutation)
Atlantic Modal Haplotype
AMH is a Y chromosome haplotype of Y-STR microsatellite variations, associated with the Haplogroup R1b.
Atlantic Modal Haplotype characterised by which marker alleles
DYS388 12 DYS390 24 DYS391 11 DYS392 13 DYS393 13 DYS394 14 (also known as DYS19)
Atlantic Modal Haplotype explanation.
Part of Haplogroup R1b
• If you have one mutation in either direction, then you are AMH 1.15+. The AMH 1.15 haplotype is also referred to as the Atlantic Modal Cluster or AMC. Generally 1.15+ puts you in Haplogroup 1 (H1), but not always.
• Most common in Atlantic Europe
Mitochondrial DNA D-loop
non coding sequence, origin of replication, promoter, hypervariable regions
Mitochondrial DNA HVR
high variability among humans, ideal for studying relationships among individuals
mtDNA haplgorup results
- Like most of you and your genealogical projects, you have road blocks and branches which cannot be connected with main trees.
- Such was the case with the Mumma surname which has many spelling variations of the surname – as with most surnames.
- Developing specific project objectives were very useful when recruiting participants as it helped them understand how their results would contribute to the big picture. As I developed these objective, it became apparent that a large representative sample would be required to establish a baseline “fingerprint” for sorting people into family groups.
Use of Autosomal Tests
- Paternity
- Relationship testing (siblings adopted)
- Police work – CODIS profiles, OmniPop
- DNA fingerprint Test
- DNAPrint – biogeographical markers
- Inherited disease
Type of Autosomal Tests
- DNA fingerprint test
- Eurasian 1.0
- EURO DNA 2.0
- SNP testing
- Genetic screening
- Genome wide genetic research
CODIS
FBI - combined DNA indexing system
What can you learn from your DNA – Genealogically Speaking
- The migration path your Ancient” ancestors and possible ethnic makeup?
- Whether men share a recent common paternal ancestor
- Whether two women or a man and a woman share a recent common maternal ancestor
