The Profiler Plus Calculations Site can be used to calculate a Random Match Probability for a ProfilerPlus DNA typing profile for any database that has been added to this site. If you wish to add a database to this page, feel free to contact the WebMaster. It is as easy as typing up a small text file of the allele frequencies.
Calculations: The heterozygote calculation for each loci is a straight Mendelian calculation of 2pq. Homozygotes are calculated as per NRC 2 [1] in the form of p2+(p*(1-p)*Ø) where Ø is the correction for population substructure. Theta is used as 0.01 for most larger databases and 0.03 for the smaller, isolated databases.
The Random Match Probability (RMP) is then calculated as the product of the nine ProfilerPlus loci frequencies. Cofiler allele frequencies are NOT available for databases marked with *.
Database Counts: The databases are made up from the following quantity of individuals:
RCMP Combined Caucasian : 79 from Edmonton, 85 from Vancouver = 164 persons (328 allele counts)
RCMP Northern Ontario Aboriginal: 129 persons (258 allele counts), 128 for Cofiler.
RCMP Saskatchewan Aboriginal: 105 persons (210 allele counts), 104 for Cofiler.
RCMP Salishan (BC) Aboriginal: 104 persons (208 allele counts)
RCMP Japanese : 113 from Kyoto region and 59 from Aomori region = 173 individuals (346 allele count)
RCMP Texas African-American: 151 from Fort Worth Texas region (302 allele count)
CFS = Centre of Forensic Sciences, Toronto, Ontario
CFS Caucasian: 293 individuals (586 allele count)
CFS African-American: 179 individuals (358 allele caount)
CFS Asian: 195 individuals (390 allele count)
CFS East Indian: 167 individuals (334 allele count)
ABD-Caucasian 200*: persons (400 allele counts)
ABD-African-American*: 195 persons (390 allele counts)To Enter the Data:
- Enter homozygotes as the same allele in both fields. Just one will give you frequency of 1.
- New Alleles: The "default frequency" is used in the calculation for alleles not found in the database. For example, the RCMP default frequencies are: Canadian Caucasian : 0.015, Northern Ontario : 0.020, Saskatchewan and Salishan: 0.0250 and from ABD, 0.013 for both databases. The CFS uses the following: Caucasian: 0.010, African-American: 0.014, Asian: 0.013 and East Indian: 0.015.
- You may notice a difference in the very rare alleles used in the calculations as opposed to what is in the Frequency Tables. If a frequency for an allele is below the default frequency, then the default frequency is used in the calculations.
- A Test Page has been added. You can use these results to check the test profile for several of the databases.
To see the raw database information and allele frequency tables, click here.
References:
[1] The Evaluation of Forensic DNA Evidence, NRC,
National Academy Press, Washington, DC 1996, Page 5, Recommendation 4.1