Accurate estimation of
recent shared ancestry is important for genetics, evolution, medicine,
conservation biology, and forensics. University of Utah investigators have
developed a maximum-likelihood method for the estimation of recent shared
ancestry (ERSA) from the number and lengths of identical by descent (IBD)
chromosomal segments derived from high-density SNP or whole-genome sequence
data. ERSA accurately
estimates the degree of relationship for up to eighth-degree relatives (e.g.
third cousins once removed), and detects relationships as distant as
twelfth-degree relatives (e.g. fifth cousins once removed). ERSA greatly
expands the range of relationships that can be estimated from genetic
ERSA is accurate in
determination of relatedness within one degree of relationship for 97% of first-
through fifth-degree relatives and 80% of sixth- and seventh-degree relatives.
Established methods only estimate kinship accurately for first- through
In analysis of large
pedigrees, ERSA can verify distant relationships without genotyping intervening
family members, reducing the need for extensive sample collection and
- >100,000 genetic ancestry tests performed annually.
- >$12,000,000 spent on genetic ancestry testing.
- Expanding market for those desiring to identify more distant
- Pedigrees: checking, merging and
- Removal of related individuals for case-control association studies and
population-based genetic analysis.
- Gene variant discovery and mapping disease-susceptibility loci.
- Identification of mass disaster/ homicide victims.
- >$65,000,000 spent annually in US alone.
need for mass disaster identification.
patent application is pending. A software package for application of this
methodology has been developed and is also available for