Ancestry-Informative Marker (AIM)
Definition
A SNP with an allele-frequency difference (FST) above 0.4 or 0.5 between continental population groups. A panel of 100-200 AIMs provides probabilistic continental ancestry assignment for an unknown contributor.
- Marker type
- SNP
- Selection threshold
- FST above 0.4 to 0.5
- Typical panel size
- 100 to 200 markers
- Output
- Probabilistic continental ancestry assignment
Common questions
Why are AIMs chosen by FST rather than by any allele-frequency difference?+
Most SNPs differ only slightly in frequency between populations and give weak individual signal. Selecting markers with a high FST concentrates the panel on the SNPs with the largest between-population frequency contrasts, so a modest panel size still yields a statistically useful ancestry estimate.
What can an AIM panel not tell investigators?+
It gives a probabilistic estimate of broad continental or regional ancestry proportions, not a specific ethnicity, nationality, or individual identity, and results are typically reported with confidence intervals rather than as a definitive classification.
Related terms
- Externally Visible Characteristic (EVC)
- An observable physical trait (eye colour, hair colour, skin tone, height, facial morphology) whose variation in the population is partly genetically determined...
- FORENSeq DNA Signature Prep
- Commercial MPS kit from Verogen that types STRs, Y-STRs, X-STRs, identity SNPs, AIMs, and EVC SNPs in a single library preparation and...
- HIrisPlex-S
- A 41-SNP externally visible characteristics (EVC) panel for simultaneous prediction of eye, hair, and skin colour, developed at Erasmus MC Rotterdam by...
- Parabon Snapshot
- A commercial DNA phenotyping service (Parabon NanoLabs, Virginia, US) that genotypes thousands of SNPs from a crime-scene sample and uses machine learning...
- SNPforID Consortium
- European-funded research consortium that published the foundational 52-SNP identity panel for forensic use in 2004-2006. The 52-plex is validated for maximum discriminating...