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Population-Specific F-ST Values for Forensic STR Markers: A Worldwide Survey

NCJ Number
Forensic Science International-Genetics Volume: 23 Dated: July 2016 Pages: 91-100
Date Published
July 2016
10 pages
This article reports on a project that shows FST (population structure quantity) can be estimated from sample allelic matching proportions within and between populations.
The interpretation of matching between DNA profiles of a person of interest and an item of evidence is undertaken using population genetic models to predict the probability of matching by chance. Calculation of matching probabilities is straightforward if allelic probabilities are known, or can be estimated, in the relevant population. It is more often the case, however, that the relevant population has not been sampled and allele frequencies are available only from a broader collection of populations as might be represented in a national or regional database. Variation of allele probabilities among the relevant populations is quantified by the population structure quantity FST and this quantity affects matching proportions. Matching within a population can be interpreted only with respect to matching between populations. The current project reports that estimates from sample allelic matching proportions within and between populations were obtained from data in 250 papers in the forensic literature, representing STR profiles at up to 24 loci from nearly 500,000 people in 446 different populations. The results suggest that theta values in current forensic use do not have the buffer of conservatism often thought. (Publisher abstract modified)

Date Published: July 1, 2016