The forensic use of ABO blood groups and VNTR allele frequencies
Frequencies of ABO and Rh blood types in the United States
|
U.S. Caucasian
|
U.S. Black
|
U.S. Asian
|
0
|
0.45
|
0.48
|
0.40
|
A
|
0.40
|
0.27
|
0.28
|
B
|
0.11
|
0.21
|
0.24
|
AB
|
0.04
|
0.04
|
0.08
|
Rh+
|
0.85
|
0.90
|
0.99
|
Rh-
|
0.15
|
0.10
|
0.01
|
a) What is the probability that a B+ blood stain in the US lefta at the scene of a crime randomly matches a person of the following ancestry
Caucasian
Black
Asian
A genetic sytem that is far more variable than the simple blood types consists of atretches of DNA called VNTRs (variable number of tandem repeats). Each of thes VNTR (also known as minisatellites) loci contain many alleles, most of which are very rate.
Binned
|
VNTR Locus D1S7
Frequencies in Caucasians Blacks
|
Binned a Caucasian D2S44
|
Ilele frequencies in samples at VNTR loci D17S79 D4S139
|
Allele
|
(n=605)
|
(n=372)
|
(n=802)
|
(n=563)
|
(n=460)
|
1
|
0.004
|
0.007
|
0.005
|
0.010
|
0.004
|
2
|
0.006
|
0.009
|
0.003
|
0.003
|
0.010
|
3
|
0.009
|
0.011
|
0.016
|
0.007
|
0.006
|
4
|
0.012
|
0.007
|
0.024
|
0.004
|
0.014
|
5
|
0.011
|
0.016
|
0.046
|
0.015
|
0.033
|
6
|
0.014
|
0.020
|
0.034
|
0.223
|
0.024
|
7
|
0.010
|
0.011
|
0.123
|
0.199
|
0.040
|
8
|
0.029
|
0.035
|
0.106
|
0.263
|
0.047
|
9
|
0.021
|
0.023
|
0.084
|
0.200
|
0.054
|
10
|
0.014
|
0.030
|
0.049
|
0.029
|
0.071
|
11
|
0.028
|
0.030
|
0.083
|
0.032
|
0.108
|
12
|
0.031
|
0.026
|
0.039
|
0.010
|
0.190
|
13
|
0.046
|
0.044
|
0.041
|
0.006
|
0.129
|
14
|
0.067
|
0.069
|
0.039
|
|
0.095
|
15
|
0.057
|
0.065
|
0.087
|
|
0.036
|
16
|
0.061
|
0.073
|
0.089
|
|
0.036
|
17
|
0.069
|
0.054
|
0.075
|
|
0.103
|
18
|
0.055
|
0.051
|
0.022
|
|
|
19
|
0.060
|
0.047
|
0.018
|
|
|
20
|
0.063
|
0.063
|
0.008
|
|
|
21
|
0.079
|
0.062
|
0.008
|
|
|
22
|
0.077
|
0.060
|
|
|
|
23
|
0.077
|
0.074
|
|
|
|
24
|
0.032
|
0.017
|
|
|
|
25
|
0.019
|
0.027
|
|
|
|
26
|
0.050
|
0.071
|
|
|
|
b) Calculate the probability that an individual picked at random from the Caucasian population has the following genotype (allele 1/allele 2)
5/22 heterozygote at D1S7
6/8 heterozygote at D2S44
5/9 heterozygote at D17S79
12/12 homozygote at D4S139
c) What is the probability that an individual has full multilocus DNA profile in b)?