Probabilistic interpretation of the Amelogenin locus

• NCJ Number: 304022
• Journal: Forensic Science International-Genetics Volume: 52 Dated: 2021
• Author(s): J. A. Bright; et al
• Date Published: 2021
• Grant Number(s): 2020-DQ-BX-0022
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)

Annotation

This article describes a method for assigning weights to genotype combinations at the Amelogenin locus.

Abstract

It is a typical practice in forensic laboratories that once the weight exceeds a threshold (such as 99 percent), then they can be considered to be resolved sufficiently to interpret (for example to load onto a database). The current study found that unless an individual is a clear major (or minor) contributor, the genotype weights do not typically exceed 99 percent for any genotype. LRs have not been traditionally assigned for the Amelogenin locus and are small compared to an LR assigned for a modern day STR multiplex where, for a more discriminatory locus, the per locus LR for a resolved contributor could be in the order of tens or hundreds. The method described in this article uses per contributor template values for a previously interpreted profile. The discrimination power is restricted, with a maximum possible LR of 2 for a fully resolved genotype, due to the limited number of alleles and hence genotypes and assuming equal proportions of genders in the population; however, it has a good power to exclude when the component is well-resolved and non-concordant with a POI. (publisher abstract modified)