Methods and systems for prediction of a DNA profile mixture ratio
AssigneeSyracuse University
InventorsMichael Marciano, Jonathan D. Adelman, Laura C. Haarer
Life of this patent
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Abstract
A system configured to characterize a ratio of contributors to a DNA mixture within a sample, the system including: a sample preparation module configured to generate initial data about the DNA mixture within the sample; a processor comprising a ratio of contributors determination module configured to: (i) receive the generated initial data; (ii) analyze the generated initial data to determine the ratio of contributors to the DNA mixture within the sample; and an output device configured to receive the determined ratio of contributors from the processor, and further configured to output information about the received determined ratio of contributors.
Claims10
A method for characterizing a ratio of contributors to a DNA mixture within a sample, the method comprising the steps of:
- obtaining a forensic DNA sample mixture having a plurality of contributors;
- characterizing the forensic DNA sample mixture to obtain a data file containing DNA sequence data representing a plurality of markers within the forensic DNA sample mixture;
- identifying which of the plurality of markers within the forensic DNA sample mixture exhibit a maximum number of alleles, or the maximum minus one, wherein each of the plurality of markers that exhibits the maximum number of alleles is identified;
- enumerating, based on the identification, all possible scenarios for contributors to the forensic DNA sample mixture based on the determined maximum number of alleles;
- determining whether each possible scenario is valid based on whether the possible scenario has every allele appearing in one of the plurality of markers appears at least once;
- determining an initial mixture ratio for each valid scenario where every allele is represented;
- identifying all possible clusters for the determined initial mixture ratios, wherein a cluster is a group of the initial mixture ratios comprising just one ratio from each of the plurality of markers that were identified;
- removing any statistical outliers from each of the identified clusters using Chebyshev's Inequality;
- identifying candidate compact clusters, wherein a compact cluster is identified as a candidate if the variance of the distance from each mixture ratio to a centroid of the compact cluster is below a certain threshold, wherein the centroid of each compact cluster represents a candidate ratio;
- and
- comparing all of the candidate ratios to all the of the mixture ratios across all of the plurality of markers;
- identifying, using Euclidean distance below a dynamic threshold, the candidate ratio with the highest number of markers containing at least one similar ratio at each marker as representing the DNA profile mixture ratio that is the ratio of contributors to the forensic DNA sample mixture.
A system configured to characterize a ratio of contributors to a DNA mixture within a sample, the system comprising a processor configured to receive data about the DNA within the sample, and further configured to perform the steps of:
- identifying, using DNA sequence data representing a plurality of markers within the forensic DNA sample mixture within the received data, which of the plurality of markers within the DNA mixture exhibit a maximum number of alleles, or the maximum minus one, wherein each of the plurality of markers that exhibits the maximum number of alleles is identified;
- enumerating, based on the identification, all possible scenarios for contributors to the DNA mixture based on the determined maximum number of alleles;
- determining whether each possible scenario is valid based on whether the possible scenario has every allele appearing in one of the plurality of markers appears at least once;
- determining an initial mixture ratio for each valid scenario where every allele is represented;
- identifying all possible clusters for the determined initial mixture ratios, wherein a cluster is a group of the initial mixture ratios comprising just one ratio from each of the plurality of markers that were identified;
- removing any statistical outliers from each of the identified clusters using Chebyshev's Inequality;
- identifying compact clusters, wherein a compact cluster is identified as a candidate if the variance of the distance from each mixture ratio to a centroid of the compact cluster is below a certain threshold, wherein the centroid of each compact cluster represents a candidate ratio;
- and
- comparing all of the candidate ratios to all the of the mixture ratios across all of the plurality of markers;
- identifying, using Euclidean distance below a dynamic threshold, the candidate ratio with the highest number of markers containing at least one similar ratio at each marker as representing the DNA profile mixture ratio that is the ratio of contributors to the forensic DNA sample mixture.
Dependencies are inferred from the claim text.