Determination of the sensitivity and specificity of sibship calculations using AmpF l STR Profiler Plus

Abstract

In circumstances where a known DNA reference sample from the deceased's belongings or biological parents is not available, more complex kinship analyses are possible. The purpose of the work reported here is to determine the sensitivity and specificity of the sibship analysis utilising multiple STR loci. Using all nine Profiler Plus loci, likelihood ratios for biologically-related siblings ranged from slightly less than 1 to over 45,000. When allelic dropout was mimicked, likelihood ratios ranged from less than 1 to over 1,000. Thus, the results of this study have a direct application to forensic laboratories faced with identifications involving sibling comparisons.

Genetic data of nine non-CODIS STRs in Chinese Han population from Guangdong Province, Southern China

“…In forensic casework, ordinary parentage cases can be expected to be solved by a commercially available multiplexes of STRs genotyping kit, e.g., PowerPlex 16 System Kit (Promega, Madison, WI, USA) or AmpFℓSTR Identifiler polymerase chain reaction (PCR) amplification kit (Applied Biosystems, Foster City, CA, USA). However, for more difficult cases, such as deficient cases [1], related individuals are involved [2,3], mutations are encountered [4], or complex kinship analysis [5,6] and common STRs cannot provide enough discriminatory power [5,7,8]. Additional STRs are needed to complement conventional analysis for obtain more information.…”

Multidisciplinary forensic approach – investigation of a neonaticide and alleged concomitant rape

“…It would have been expected that for 14 successful loci shared by the mother and her offspring, the value of the likelihood ratio would be higher. Nevertheless, a value of 445 is still high enough to conclude that the remains were those of the progeny of the complainant, 15 thus corroborating the circumstances of the event and proving one of the required elements that attenuate the crime to manslaughter. The second consideration for leniency rests on proving that the crime was committed less than 12 months post-partum.…”

A grey zone approach for evaluation of 15 short tandem repeat loci in sibship analysis: A pilot study in Indian subjects

“…2 With every new DNA marker system making its way in forensic laboratories different authors have prescribed threshold CSI for inferring the likelihood of probable sibship. Gaytmenn et al 5 have recently reported significant risks of false inclusion associated with this approach when 3, 6 and 9 loci STR systems are used. Tzeng et al 4 using 15 loci STR panel established a presumptive cutting point of CSI at P3.0 for sibship determination.…”

“…Previous studies using various STR locus combinations reflect that it is difficult to determine exactly how many loci are necessary to achieve a certain level of power in sibship inferences and highly impossible to provide a universal CSI cut-off point for demarcating siblings from unrelated group. 4,5 These studies also suggest for creation of an initial reference standard in every DNA laboratory on which the decision to apply the test convincingly can be taken. The present case-control sibship study in Indian subjects was designed with an aim of generating suitable values of CSI using the 15 panel STR multiplex systems.…”