Drop-out probabilities of IrisPlex SNP alleles

TY - GEN

T1 - Drop-out probabilities of IrisPlex SNP alleles

AU - Andersen, Jeppe Dyrberg

AU - Tvedebrink, Torben

AU - Mogensen, Helle Smidt

AU - Børsting, Claus

AU - Morling, Niels

PY - 2013

Y1 - 2013

N2 - In certain crime cases, information about a perpetrator's phenotype, including eye colour, may be a valuable tool if no DNA profile of any suspect or individual in the DNA database matches the DNA profile found at the crime scene. Often, the available DNA material is sparse and allelic drop-out of true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop-out when the amount of DNA was greater than 125. pg for 29 cycles of PCR and greater than 62. pg for 30 cycles of PCR. With the use of a logistic regression model, we estimated the allele specific probability of drop-out in heterozygote systems based on the signal strength of the observed allele. The probability of drop-out in heterozygote systems depended on the signal strength of the observed allele as well as the number of PCR and SBE cycles.

AB - In certain crime cases, information about a perpetrator's phenotype, including eye colour, may be a valuable tool if no DNA profile of any suspect or individual in the DNA database matches the DNA profile found at the crime scene. Often, the available DNA material is sparse and allelic drop-out of true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop-out when the amount of DNA was greater than 125. pg for 29 cycles of PCR and greater than 62. pg for 30 cycles of PCR. With the use of a logistic regression model, we estimated the allele specific probability of drop-out in heterozygote systems based on the signal strength of the observed allele. The probability of drop-out in heterozygote systems depended on the signal strength of the observed allele as well as the number of PCR and SBE cycles.

M3 - Conference article

SN - 1875-1768

VL - 4

SP - e238-e239

JO - Forensic Society International: Genetics Supplement Series

JF - Forensic Society International: Genetics Supplement Series

IS - 1

M1 - 1

T2 - 25th

Y2 - 2 September 2013 through 7 September 2013

ER -